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Title: A History of Science — Volume 1

Author: Henry Smith Williams
Edward Huntington Williams

Release date: April 1, 1999 [eBook #1705]
Most recently updated: January 29, 2013

Language: English

Other information and formats: www.gutenberg.org/ebooks/1705

Credits: Produced by Charles Keller, and David Widger

*** START OF THE PROJECT GUTENBERG EBOOK A HISTORY OF
SCIENCE — VOLUME 1 ***

A HISTORY OF SCIENCE

BY HENRY SMITH WILLIAMS, M.D., LL.D.

ASSISTED BY EDWARD H. WILLIAMS, M.D.

IN FIVE VOLUMES

VOLUME I. THE BEGINNINGS OF SCIENCE

CONTENTS

A HISTORY OF SCIENCE

BOOK I

I. PREHISTORIC SCIENCE
II. EGYPTIAN SCIENCE
III. SCIENCE OF BABYLONIA AND ASSYRIA
IV. THE DEVELOPMENT OF THE ALPHABET

V. THE BEGINNINGS OF GREEK SCIENCE
VI. THE EARLY GREEK PHILOSOPHERS IN ITALY
VII. GREEK SCIENCE IN THE EARLY ATTIC PERIOD
VIII. POST-SOCRATIC SCIENCE AT ATHENS—PLATO,
ARISTOTLE, AND THEOPHRASTUS
IX. GREEK SCIENCE OF THE ALEXANDRIAN OR
HELLENISTIC PERIOD
X. SCIENCE OF THE ROMAN PERIOD
XI. A RETROSPECTIVE GLANCE AT CLASSICAL
SCIENCE

APPENDIX
CHAPTER I. PREHISTORIC SCIENCE
CHAPTER II. EGYPTIAN SCIENCE
CHAPTER III. SCIENCE OF BABYLONIA
AND ASSYRIA
CHAPTER IV. THE DEVELOPMENT OF
THE ALPHABET
CHAPTER V. THE BEGINNINGS OF
GREEK SCIENCE
CHAPTER VI. THE EARLY GREEK
PHILOSOPHERS IN ITALY
CHAPTER VII. GREEK SCIENCE IN THE
EARLY ATTIC PERIOD
CHAPTER VIII. POST-SOCRATIC SCIENCE
AT ATHENS

CHAPTER IX. GREEK SCIENCE OF THE
ALEXANDRIAN OR HELLENISTIC PERIOD
CHAPTER X. SCIENCE OF THE ROMAN
PERIOD
CHAPTER XI. A RETROSPECTIVE
GLANCE AT CLASSICAL SCIENCE

A HISTORY OF SCIENCE

BOOK I
Should the story that is about to be unfolded be found to lack interest, the
writers must stand convicted of unpardonable lack of art. Nothing but
dulness in the telling could mar the story, for in itself it is the record of the
growth of those ideas that have made our race and its civilization what they
are; of ideas instinct with human interest, vital with meaning for our race;
fundamental in their influence on human development; part and parcel of
the mechanism of human thought on the one hand, and of practical
civilization on the other. Such a phrase as "fundamental principles" may
seem at first thought a hard saying, but the idea it implies is less repellent
than the phrase itself, for the fundamental principles in question are so
closely linked with the present interests of every one of us that they lie
within the grasp of every average man and woman—nay, of every well-
developed boy and girl. These principles are not merely the stepping-stones
to culture, the prerequisites of knowledge—they are, in themselves, an
essential part of the knowledge of every cultivated person.
It is our task, not merely to show what these principles are, but to point
out how they have been discovered by our predecessors. We shall trace the
growth of these ideas from their first vague beginnings. We shall see how
vagueness of thought gave way to precision; how a general truth, once
grasped and formulated, was found to be a stepping-stone to other truths.
We shall see that there are no isolated facts, no isolated principles, in
nature; that each part of our story is linked by indissoluble bands with that
which goes before, and with that which comes after. For the most part the
discovery of this principle or that in a given sequence is no accident.
Galileo and Keppler must precede Newton. Cuvier and Lyall must come
before Darwin;—Which, after all, is no more than saying that in our Temple
of Science, as in any other piece of architecture, the foundation must
precede the superstructure.
We shall best understand our story of the growth of science if we think of
each new principle as a stepping-stone which must fit into its own particular
niche; and if we reflect that the entire structure of modern civilization
would be different from what it is, and less perfect than it is, had not that

particular stepping-stone been found and shaped and placed in position.
Taken as a whole, our stepping-stones lead us up and up towards the
alluring heights of an acropolis of knowledge, on which stands the Temple
of Modern Science. The story of the building of this wonderful structure is
in itself fascinating and beautiful.

I. PREHISTORIC SCIENCE
To speak of a prehistoric science may seem like a contradiction of terms.
The word prehistoric seems to imply barbarism, while science, clearly
enough, seems the outgrowth of civilization; but rightly considered, there is
no contradiction. For, on the one hand, man had ceased to be a barbarian
long before the beginning of what we call the historical period; and, on the
other hand, science, of a kind, is no less a precursor and a cause of
civilization than it is a consequent. To get this clearly in mind, we must ask
ourselves: What, then, is science? The word runs glibly enough upon the
tongue of our every-day speech, but it is not often, perhaps, that they who
use it habitually ask themselves just what it means. Yet the answer is not
difficult. A little attention will show that science, as the word is commonly
used, implies these things: first, the gathering of knowledge through
observation; second, the classification of such knowledge, and through this
classification, the elaboration of general ideas or principles. In the familiar
definition of Herbert Spencer, science is organized knowledge.
Now it is patent enough, at first glance, that the veriest savage must have
been an observer of the phenomena of nature. But it may not be so obvious
that he must also have been a classifier of his observations—an organizer of
knowledge. Yet the more we consider the case, the more clear it will
become that the two methods are too closely linked together to be
dissevered. To observe outside phenomena is not more inherent in the
nature of the mind than to draw inferences from these phenomena. A deer
passing through the forest scents the ground and detects a certain odor. A
sequence of ideas is generated in the mind of the deer. Nothing in the deer's
experience can produce that odor but a wolf; therefore the scientific
inference is drawn that wolves have passed that way. But it is a part of the
deer's scientific knowledge, based on previous experience, individual and
racial; that wolves are dangerous beasts, and so, combining direct
observation in the present with the application of a general principle based
on past experience, the deer reaches the very logical conclusion that it may
wisely turn about and run in another direction. All this implies, essentially, a
comprehension and use of scientific principles; and, strange as it seems to

speak of a deer as possessing scientific knowledge, yet there is really no
absurdity in the statement. The deer does possess scientific knowledge;
knowledge differing in degree only, not in kind, from the knowledge of a
Newton. Nor is the animal, within the range of its intelligence, less logical,
less scientific in the application of that knowledge, than is the man. The
animal that could not make accurate scientific observations of its
surroundings, and deduce accurate scientific conclusions from them, would
soon pay the penalty of its lack of logic.
What is true of man's precursors in the animal scale is, of course, true in a
wider and fuller sense of man himself at the very lowest stage of his
development. Ages before the time which the limitations of our knowledge
force us to speak of as the dawn of history, man had reached a high stage of
development. As a social being, he had developed all the elements of a
primitive civilization. If, for convenience of classification, we speak of his
state as savage, or barbaric, we use terms which, after all, are relative, and
which do not shut off our primitive ancestors from a tolerably close
association with our own ideals. We know that, even in the Stone Age, man
had learned how to domesticate animals and make them useful to him, and
that he had also learned to cultivate the soil. Later on, doubtless by slow
and painful stages, he attained those wonderful elements of knowledge that
enabled him to smelt metals and to produce implements of bronze, and then
of iron. Even in the Stone Age he was a mechanic of marvellous skill, as
any one of to-day may satisfy himself by attempting to duplicate such an
implement as a chipped arrow-head. And a barbarian who could fashion an
axe or a knife of bronze had certainly gone far in his knowledge of
scientific principles and their practical application. The practical application
was, doubtless, the only thought that our primitive ancestor had in mind;
quite probably the question as to principles that might be involved troubled
him not at all. Yet, in spite of himself, he knew certain rudimentary
principles of science, even though he did not formulate them.
Let us inquire what some of these principles are. Such an inquiry will, as
it were, clear the ground for our structure of science. It will show the plane
of knowledge on which historical investigation begins. Incidentally,
perhaps, it will reveal to us unsuspected affinities between ourselves and
our remote ancestor. Without attempting anything like a full analysis, we
may note in passing, not merely what primitive man knew, but what he did

not know; that at least a vague notion may be gained of the field for
scientific research that lay open for historic man to cultivate.
It must be understood that the knowledge of primitive man, as we are
about to outline it, is inferential. We cannot trace the development of these
principles, much less can we say who discovered them. Some of them, as
already suggested, are man's heritage from non-human ancestors. Others
can only have been grasped by him after he had reached a relatively high
stage of human development. But all the principles here listed must surely
have been parts of our primitive ancestor's knowledge before those earliest
days of Egyptian and Babylonian civilization, the records of which
constitute our first introduction to the so-called historical period. Taken
somewhat in the order of their probable discovery, the scientific ideas of
primitive man may be roughly listed as follows:
1. Primitive man must have conceived that the earth is flat and of
limitless extent. By this it is not meant to imply that he had a distinct
conception of infinity, but, for that matter, it cannot be said that any one to-
day has a conception of infinity that could be called definite. But, reasoning
from experience and the reports of travellers, there was nothing to suggest
to early man the limit of the earth. He did, indeed, find in his wanderings,
that changed climatic conditions barred him from farther progress; but
beyond the farthest reaches of his migrations, the seemingly flat land-
surfaces and water-surfaces stretched away unbroken and, to all
appearances, without end. It would require a reach of the philosophical
imagination to conceive a limit to the earth, and while such imaginings may
have been current in the prehistoric period, we can have no proof of them,
and we may well postpone consideration of man's early dreamings as to the
shape of the earth until we enter the historical epoch where we stand on
firm ground.
2. Primitive man must, from a very early period, have observed that the
sun gives heat and light, and that the moon and stars seem to give light only
and no heat. It required but a slight extension of this observation to note that
the changing phases of the seasons were associated with the seeming
approach and recession of the sun. This observation, however, could not
have been made until man had migrated from the tropical regions, and had
reached a stage of mechanical development enabling him to live in
subtropical or temperate zones. Even then it is conceivable that a long

period must have elapsed before a direct causal relation was felt to exist
between the shifting of the sun and the shifting of the seasons; because, as
every one knows, the periods of greatest heat in summer and greatest cold
in winter usually come some weeks after the time of the solstices. Yet, the
fact that these extremes of temperature are associated in some way with the
change of the sun's place in the heavens must, in time, have impressed itself
upon even a rudimentary intelligence. It is hardly necessary to add that this
is not meant to imply any definite knowledge of the real meaning of, the
seeming oscillations of the sun. We shall see that, even at a relatively late
period, the vaguest notions were still in vogue as to the cause of the sun's
changes of position.
That the sun, moon, and stars move across the heavens must obviously
have been among the earliest scientific observations. It must not be inferred,
however, that this observation implied a necessary conception of the
complete revolution of these bodies about the earth. It is unnecessary to
speculate here as to how the primitive intelligence conceived the transfer of
the sun from the western to the eastern horizon, to be effected each night,
for we shall have occasion to examine some historical speculations
regarding this phenomenon. We may assume, however, that the idea of the
transfer of the heavenly bodies beneath the earth (whatever the conception
as to the form of that body) must early have presented itself.
It required a relatively high development of the observing faculties, yet a
development which man must have attained ages before the historical
period, to note that the moon has a secondary motion, which leads it to shift
its relative position in the heavens, as regards the stars; that the stars
themselves, on the other hand, keep a fixed relation as regards one another,
with the notable exception of two or three of the most brilliant members of
the galaxy, the latter being the bodies which came to be known finally as
planets, or wandering stars. The wandering propensities of such brilliant
bodies as Jupiter and Venus cannot well have escaped detection. We may
safely assume, however, that these anomalous motions of the moon and
planets found no explanation that could be called scientific until a relatively
late period.
3. Turning from the heavens to the earth, and ignoring such primitive
observations as that of the distinction between land and water, we may note
that there was one great scientific law which must have forced itself upon

the attention of primitive man. This is the law of universal terrestrial
gravitation. The word gravitation suggests the name of Newton, and it may
excite surprise to hear a knowledge of gravitation ascribed to men who
preceded that philosopher by, say, twenty-five or fifty thousand years. Yet
the slightest consideration of the facts will make it clear that the great
central law that all heavy bodies fall directly towards the earth, cannot have
escaped the attention of the most primitive intelligence. The arboreal habits
of our primitive ancestors gave opportunities for constant observation of the
practicalities of this law. And, so soon as man had developed the mental
capacity to formulate ideas, one of the earliest ideas must have been the
conception, however vaguely phrased in words, that all unsupported bodies
fall towards the earth. The same phenomenon being observed to operate on
water-surfaces, and no alteration being observed in its operation in different
portions of man's habitat, the most primitive wanderer must have come to
have full faith in the universal action of the observed law of gravitation.
Indeed, it is inconceivable that he can have imagined a place on the earth
where this law does not operate. On the other hand, of course, he never
grasped the conception of the operation of this law beyond the close
proximity of the earth. To extend the reach of gravitation out to the moon
and to the stars, including within its compass every particle of matter in the
universe, was the work of Newton, as we shall see in due course. Meantime
we shall better understand that work if we recall that the mere local fact of
terrestrial gravitation has been the familiar knowledge of all generations of
men. It may further help to connect us in sympathy with our primeval
ancestor if we recall that in the attempt to explain this fact of terrestrial
gravitation Newton made no advance, and we of to-day are scarcely more
enlightened than the man of the Stone Age. Like the man of the Stone Age,
we know that an arrow shot into the sky falls back to the earth. We can
calculate, as he could not do, the arc it will describe and the exact speed of
its fall; but as to why it returns to earth at all, the greatest philosopher of to-
day is almost as much in the dark as was the first primitive bowman that
ever made the experiment.
Other physical facts going to make up an elementary science of
mechanics, that were demonstratively known to prehistoric man, were such
as these: the rigidity of solids and the mobility of liquids; the fact that
changes of temperature transform solids to liquids and vice versa—that
heat, for example, melts copper and even iron, and that cold congeals water;

and the fact that friction, as illustrated in the rubbing together of two sticks,
may produce heat enough to cause a fire. The rationale of this last
experiment did not receive an explanation until about the beginning of the
nineteenth century of our own era. But the experimental fact was so well
known to prehistoric man that he employed this method, as various savage
tribes employ it to this day, for the altogether practical purpose of making a
fire; just as he employed his practical knowledge of the mutability of solids
and liquids in smelting ores, in alloying copper with tin to make bronze, and
in casting this alloy in molds to make various implements and weapons.
Here, then, were the germs of an elementary science of physics. Meanwhile
such observations as that of the solution of salt in water may be considered
as giving a first lesson in chemistry, but beyond such altogether
rudimentary conceptions chemical knowledge could not have gone—unless,
indeed, the practical observation of the effects of fire be included; nor can
this well be overlooked, since scarcely another single line of practical
observation had a more direct influence in promoting the progress of man
towards the heights of civilization.
4. In the field of what we now speak of as biological knowledge,
primitive man had obviously the widest opportunity for practical
observation. We can hardly doubt that man attained, at an early day, to that
conception of identity and of difference which Plato places at the head of
his metaphysical system. We shall urge presently that it is precisely such
general ideas as these that were man's earliest inductions from observation,
and hence that came to seem the most universal and "innate" ideas of his
mentality. It is quite inconceivable, for example, that even the most
rudimentary intelligence that could be called human could fail to
discriminate between living things and, let us say, the rocks of the earth.
The most primitive intelligence, then, must have made a tacit classification
of the natural objects about it into the grand divisions of animate and
inanimate nature. Doubtless the nascent scientist may have imagined life
animating many bodies that we should call inanimate—such as the sun,
wandering planets, the winds, and lightning; and, on the other hand, he may
quite likely have relegated such objects as trees to the ranks of the non-
living; but that he recognized a fundamental distinction between, let us say,
a wolf and a granite bowlder we cannot well doubt. A step beyond this—a
step, however, that may have required centuries or millenniums in the
taking—must have carried man to a plane of intelligence from which a

primitive Aristotle or Linnaeus was enabled to note differences and
resemblances connoting such groups of things as fishes, birds, and furry
beasts. This conception, to be sure, is an abstraction of a relatively high
order. We know that there are savage races to-day whose language contains
no word for such an abstraction as bird or tree. We are bound to believe,
then, that there were long ages of human progress during which the highest
man had attained no such stage of abstraction; but, on the other hand, it is
equally little in question that this degree of mental development had been
attained long before the opening of our historical period. The primeval man,
then, whose scientific knowledge we are attempting to predicate, had
become, through his conception of fishes, birds, and hairy animals as
separate classes, a scientific zoologist of relatively high attainments.
In the practical field of medical knowledge, a certain stage of
development must have been reached at a very early day. Even animals pick
and choose among the vegetables about them, and at times seek out certain
herbs quite different from their ordinary food, practising a sort of instinctive
therapeutics. The cat's fondness for catnip is a case in point. The most
primitive man, then, must have inherited a racial or instinctive knowledge
of the medicinal effects of certain herbs; in particular he must have had
such elementary knowledge of toxicology as would enable him to avoid
eating certain poisonous berries. Perhaps, indeed, we are placing the effect
before the cause to some extent; for, after all, the animal system possesses
marvellous powers of adaption, and there is perhaps hardly any poisonous
vegetable which man might not have learned to eat without deleterious
effect, provided the experiment were made gradually. To a certain extent,
then, the observed poisonous effects of numerous plants upon the human
system are to be explained by the fact that our ancestors have avoided this
particular vegetable. Certain fruits and berries might have come to have
been a part of man's diet, had they grown in the regions he inhabited at an
early day, which now are poisonous to his system. This thought, however,
carries us too far afield. For practical purposes, it suffices that certain roots,
leaves, and fruits possess principles that are poisonous to the human system,
and that unless man had learned in some way to avoid these, our race must
have come to disaster. In point of fact, he did learn to avoid them; and such
evidence implied, as has been said, an elementary knowledge of toxicology.
Coupled with this knowledge of things dangerous to the human system,
there must have grown up, at a very early day, a belief in the remedial

character of various vegetables as agents to combat disease. Here, of
course, was a rudimentary therapeutics, a crude principle of an empirical art
of medicine. As just suggested, the lower order of animals have an
instinctive knowledge that enables them to seek out remedial herbs (though
we probably exaggerate the extent of this instinctive knowledge); and if this
be true, man must have inherited from his prehuman ancestors this instinct
along with the others. That he extended this knowledge through observation
and practice, and came early to make extensive use of drugs in the
treatment of disease, is placed beyond cavil through the observation of the
various existing barbaric tribes, nearly all of whom practice elaborate
systems of therapeutics. We shall have occasion to see that even within
historic times the particular therapeutic measures employed were often
crude, and, as we are accustomed to say, unscientific; but even the crudest
of them are really based upon scientific principles, inasmuch as their
application implies the deduction of principles of action from previous
observations. Certain drugs are applied to appease certain symptoms of
disease because in the belief of the medicine-man such drugs have proved
beneficial in previous similar cases.
All this, however, implies an appreciation of the fact that man is subject
to "natural" diseases, and that if these diseases are not combated, death may
result. But it should be understood that the earliest man probably had no
such conception as this. Throughout all the ages of early development, what
we call "natural" disease and "natural" death meant the onslaught of a
tangible enemy. A study of this question leads us to some very curious
inferences. The more we look into the matter the more the thought forces
itself home to us that the idea of natural death, as we now conceive it, came
to primitive man as a relatively late scientific induction. This thought seems
almost startling, so axiomatic has the conception "man is mortal" come to
appear. Yet a study of the ideas of existing savages, combined with our
knowledge of the point of view from which historical peoples regard
disease, make it more probable that the primitive conception of human life
did not include the idea of necessary death. We are told that the Australian
savage who falls from a tree and breaks his neck is not regarded as having
met a natural death, but as having been the victim of the magical practices
of the "medicine-man" of some neighboring tribe. Similarly, we shall find
that the Egyptian and the Babylonian of the early historical period
conceived illness as being almost invariably the result of the machinations

of an enemy. One need but recall the superstitious observances of the
Middle Ages, and the yet more recent belief in witchcraft, to realize how
generally disease has been personified as a malicious agent invoked by an
unfriendly mind. Indeed, the phraseology of our present-day speech is still
reminiscent of this; as when, for example, we speak of an "attack of fever,"
and the like.
When, following out this idea, we picture to ourselves the conditions
under which primitive man lived, it will be evident at once how relatively
infrequent must have been his observation of what we usually term natural
death. His world was a world of strife; he lived by the chase; he saw
animals kill one another; he witnessed the death of his own fellows at the
hands of enemies. Naturally enough, then, when a member of his family
was "struck down" by invisible agents, he ascribed this death also to
violence, even though the offensive agent was concealed. Moreover, having
very little idea of the lapse of time—being quite unaccustomed, that is, to
reckon events from any fixed era—primitive man cannot have gained at
once a clear conception of age as applied to his fellows. Until a relatively
late stage of development made tribal life possible, it cannot have been
usual for man to have knowledge of his grandparents; as a rule he did not
know his own parents after he had passed the adolescent stage and had been
turned out upon the world to care for himself. If, then, certain of his fellow-
beings showed those evidences of infirmity which we ascribe to age, it did
not necessarily follow that he saw any association between such infirmities
and the length of time which those persons had lived. The very fact that
some barbaric nations retain the custom of killing the aged and infirm, in
itself suggests the possibility that this custom arose before a clear
conception had been attained that such drags upon the community would be
removed presently in the natural order of things. To a person who had no
clear conception of the lapse of time and no preconception as to the limited
period of man's life, the infirmities of age might very naturally be ascribed
to the repeated attacks of those inimical powers which were understood
sooner or later to carry off most members of the race. And coupled with this
thought would go the conception that inasmuch as some people through
luck had escaped the vengeance of all their enemies for long periods, these
same individuals might continue to escape for indefinite periods of the
future. There were no written records to tell primeval man of events of long
ago. He lived in the present, and his sweep of ideas scarcely carried him

back beyond the limits of his individual memory. But memory is observed
to be fallacious. It must early have been noted that some people recalled
events which other participants in them had quite forgotten, and it may
readily enough have been inferred that those members of the tribe who
spoke of events which others could not recall were merely the ones who
were gifted with the best memories. If these reached a period when their
memories became vague, it did not follow that their recollections had
carried them back to the beginnings of their lives. Indeed, it is contrary to
all experience to believe that any man remembers all the things he has once
known, and the observed fallaciousness and evanescence of memory would
thus tend to substantiate rather than to controvert the idea that various
members of a tribe had been alive for an indefinite period.
Without further elaborating the argument, it seems a justifiable inference
that the first conception primitive man would have of his own life would
not include the thought of natural death, but would, conversely, connote the
vague conception of endless life. Our own ancestors, a few generations
removed, had not got rid of this conception, as the perpetual quest of the
spring of eternal youth amply testifies. A naturalist of our own day has
suggested that perhaps birds never die except by violence. The thought,
then, that man has a term of years beyond which "in the nature of things,"
as the saying goes, he may not live, would have dawned but gradually upon
the developing intelligence of successive generations of men; and we
cannot feel sure that he would fully have grasped the conception of a
"natural" termination of human life until he had shaken himself free from
the idea that disease is always the result of the magic practice of an enemy.
Our observation of historical man in antiquity makes it somewhat doubtful
whether this conception had been attained before the close of the prehistoric
period. If it had, this conception of the mortality of man was one of the
most striking scientific inductions to which prehistoric man attained.
Incidentally, it may be noted that the conception of eternal life for the
human body being a more primitive idea than the conception of natural
death, the idea of the immortality of the spirit would be the most natural of
conceptions. The immortal spirit, indeed, would be but a correlative of the
immortal body, and the idea which we shall see prevalent among the
Egyptians that the soul persists only as long as the body is intact—the idea
upon which the practice of mummifying the dead depended—finds a ready
explanation. But this phase of the subject carries us somewhat afield. For

our present purpose it suffices to have pointed out that the conception of
man's mortality—a conception which now seems of all others the most
natural and "innate"—was in all probability a relatively late scientific
induction of our primitive ancestors.
5. Turning from the consideration of the body to its mental complement,
we are forced to admit that here, also, our primitive man must have made
certain elementary observations that underlie such sciences as psychology,
mathematics, and political economy. The elementary emotions associated
with hunger and with satiety, with love and with hatred, must have forced
themselves upon the earliest intelligence that reached the plane of conscious
self-observation. The capacity to count, at least to the number four or five,
is within the range of even animal intelligence. Certain savages have gone
scarcely farther than this; but our primeval ancestor, who was forging on
towards civilization, had learned to count his fingers and toes, and to
number objects about him by fives and tens in consequence, before he
passed beyond the plane of numerous existing barbarians. How much
beyond this he had gone we need not attempt to inquire; but the relatively
high development of mathematics in the early historical period suggests that
primeval man had attained a not inconsiderable knowledge of numbers. The
humdrum vocation of looking after a numerous progeny must have taught
the mother the rudiments of addition and subtraction; and the elements of
multiplication and division are implied in the capacity to carry on even the
rudest form of barter, such as the various tribes must have practised from an
early day.
As to political ideas, even the crudest tribal life was based on certain
conceptions of ownership, at least of tribal ownership, and the application
of the principle of likeness and difference to which we have already
referred. Each tribe, of course, differed in some regard from other tribes,
and the recognition of these differences implied in itself a political
classification. A certain tribe took possession of a particular hunting-
ground, which became, for the time being, its home, and over which it came
to exercise certain rights. An invasion of this territory by another tribe
might lead to war, and the banding together of the members of the tribe to
repel the invader implied both a recognition of communal unity and a
species of prejudice in favor of that community that constituted a primitive
patriotism. But this unity of action in opposing another tribe would not
prevent a certain rivalry of interest between the members of the same tribe,

which would show itself more and more prominently as the tribe increased
in size. The association of two or more persons implies, always, the
ascendency of some and the subordination of others. Leadership and
subordination are necessary correlatives of difference of physical and
mental endowment, and rivalry between leaders would inevitably lead to
the formation of primitive political parties. With the ultimate success and
ascendency of one leader, who secures either absolute power or power
modified in accordance with the advice of subordinate leaders, we have the
germs of an elaborate political system—an embryo science of government.
Meanwhile, the very existence of such a community implies the
recognition on the part of its members of certain individual rights, the
recognition of which is essential to communal harmony. The right of
individual ownership of the various articles and implements of every-day
life must be recognized, or all harmony would be at an end. Certain rules of
justice—primitive laws—must, by common consent, give protection to the
weakest members of the community. Here are the rudiments of a system of
ethics. It may seem anomalous to speak of this primitive morality, this early
recognition of the principles of right and wrong, as having any relation to
science. Yet, rightly considered, there is no incongruity in such a citation.
There cannot well be a doubt that the adoption of those broad principles of
right and wrong which underlie the entire structure of modern civilization
was due to scientific induction,—in other words, to the belief, based on
observation and experience, that the principles implied were essential to
communal progress. He who has scanned the pageant of history knows how
often these principles seem to be absent in the intercourse of men and
nations. Yet the ideal is always there as a standard by which all deeds are
judged.
It would appear, then, that the entire superstructure of later science had
its foundation in the knowledge and practice of prehistoric man. The
civilization of the historical period could not have advanced as it has had
there not been countless generations of culture back of it. The new
principles of science could not have been evolved had there not been great
basal principles which ages of unconscious experiment had impressed upon
the mind of our race. Due meed of praise must be given, then, to our
primitive ancestor for his scientific accomplishments; but justice demands
that we should look a little farther and consider the reverse side of the
picture. We have had to do, thus far, chiefly with the positive side of

accomplishment. We have pointed out what our primitive ancestor knew,
intimating, perhaps, the limitations of his knowledge; but we have had little
to say of one all-important feature of his scientific theorizing. The feature in
question is based on the highly scientific desire and propensity to find
explanations for the phenomena of nature. Without such desire no progress
could be made. It is, as we have seen, the generalizing from experience that
constitutes real scientific progress; and yet, just as most other good things
can be overdone, this scientific propensity may be carried to a disastrous
excess.
Primeval man did not escape this danger. He observed, he reasoned, he
found explanations; but he did not always discriminate as to the logicality
of his reasonings. He failed to recognize the limitations of his knowledge.
The observed uniformity in the sequence of certain events impressed on his
mind the idea of cause and effect. Proximate causes known, he sought
remoter causes; childlike, his inquiring mind was always asking, Why? and,
childlike, he demanded an explicit answer. If the forces of nature seemed to
combat him, if wind and rain opposed his progress and thunder and
lightning seemed to menace his existence, he was led irrevocably to think of
those human foes who warred with him, and to see, back of the warfare of
the elements, an inscrutable malevolent intelligence which took this method
to express its displeasure. But every other line of scientific observation
leads equally, following back a sequence of events, to seemingly causeless
beginnings. Modern science can explain the lightning, as it can explain a
great number of the mysteries which the primeval intelligence could not
penetrate. But the primordial man could not wait for the revelations of
scientific investigation: he must vault at once to a final solution of all
scientific problems. He found his solution by peopling the world with
invisible forces, anthropomorphic in their conception, like himself in their
thought and action, differing only in the limitations of their powers. His
own dream existence gave him seeming proof of the existence of an alter
ego, a spiritual portion of himself that could dissever itself from his body
and wander at will; his scientific inductions seemed to tell him of a world of
invisible beings, capable of influencing him for good or ill. From the
scientific exercise of his faculties he evolved the all-encompassing
generalizations of invisible and all-powerful causes back of the phenomena
of nature. These generalizations, early developed and seemingly supported
by the observations of countless generations, came to be among the most

firmly established scientific inductions of our primeval ancestor. They
obtained a hold upon the mentality of our race that led subsequent
generations to think of them, sometimes to speak of them, as "innate" ideas.
The observations upon which they were based are now, for the most part,
susceptible of other interpretations; but the old interpretations have
precedent and prejudice back of them, and they represent ideas that are
more difficult than almost any others to eradicate. Always, and everywhere,
superstitions based upon unwarranted early scientific deductions have been
the most implacable foes to the progress of science. Men have built systems
of philosophy around their conception of anthropomorphic deities; they
have linked to these systems of philosophy the allied conception of the
immutability of man's spirit, and they have asked that scientific progress
should stop short at the brink of these systems of philosophy and accept
their dictates as final. Yet there is not to-day in existence, and there never
has been, one jot of scientific evidence for the existence of these intangible
anthropomorphic powers back of nature that is not susceptible of scientific
challenge and of more logical interpretation. In despite of which the
superstitious beliefs are still as firmly fixed in the minds of a large majority
of our race as they were in the mind of our prehistoric ancestor. The fact of
this baleful heritage must not be forgotten in estimating the debt of gratitude
which historic man owes to his barbaric predecessor.

II. EGYPTIAN SCIENCE
In the previous chapter we have purposely refrained from referring to any
particular tribe or race of historical man. Now, however, we are at the
beginnings of national existence, and we have to consider the
accomplishments of an individual race; or rather, perhaps, of two or more
races that occupied successively the same geographical territory. But even
now our studies must for a time remain very general; we shall see little or
nothing of the deeds of individual scientists in the course of our study of
Egyptian culture. We are still, it must be understood, at the beginnings of
history; indeed, we must first bridge over the gap from the prehistoric
before we may find ourselves fairly on the line of march of historical
science.
At the very outset we may well ask what constitutes the distinction
between prehistoric and historic epochs—a distinction which has been
constantly implied in much that we have said. The reply savors somewhat
of vagueness. It is a distinction having to do, not so much with facts of
human progress as with our interpretation of these facts. When we speak of
the dawn of history we must not be understood to imply that, at the period
in question, there was any sudden change in the intellectual status of the
human race or in the status of any individual tribe or nation of men. What
we mean is that modern knowledge has penetrated the mists of the past for
the period we term historical with something more of clearness and
precision than it has been able to bring to bear upon yet earlier periods.
New accessions of knowledge may thus shift from time to time the bounds
of the so-called historical period. The clearest illustration of this is
furnished by our interpretation of Egyptian history. Until recently the
biblical records of the Hebrew captivity or service, together with the similar
account of Josephus, furnished about all that was known of Egyptian
history even of so comparatively recent a time as that of Ramses II.
(fifteenth century B.C.), and from that period on there was almost a
complete gap until the story was taken up by the Greek historians
Herodotus and Diodorus. It is true that the king-lists of the Alexandrian
historian, Manetho, were all along accessible in somewhat garbled copies.

But at best they seemed to supply unintelligible lists of names and dates
which no one was disposed to take seriously. That they were, broadly
speaking, true historical records, and most important historical records at
that, was not recognized by modern scholars until fresh light had been
thrown on the subject from altogether new sources.
These new sources of knowledge of ancient history demand a moment's
consideration. They are all-important because they have been the means of
extending the historical period of Egyptian history (using the word history
in the way just explained) by three or four thousand years. As just
suggested, that historical period carried the scholarship of the early
nineteenth century scarcely beyond the fifteenth century B.C., but to-day's
vision extends with tolerable clearness to about the middle of the fifth
millennium B.C. This change has been brought about chiefly through study
of the Egyptian hieroglyphics. These hieroglyphics constitute, as we now
know, a highly developed system of writing; a system that was practised for
some thousands of years, but which fell utterly into disuse in the later
Roman period, and the knowledge of which passed absolutely from the
mind of man. For about two thousand years no one was able to read, with
any degree of explicitness, a single character of this strange script, and the
idea became prevalent that it did not constitute a real system of writing, but
only a more or less barbaric system of religious symbolism. The falsity of
this view was shown early in the nineteenth century when Dr. Thomas
Young was led, through study of the famous trilingual inscription of the
Rosetta stone, to make the first successful attempt at clearing up the
mysteries of the hieroglyphics.
This is not the place to tell the story of his fascinating discoveries and
those of his successors. That story belongs to nineteenth-century science,
not to the science of the Egyptians. Suffice it here that Young gained the
first clew to a few of the phonetic values of the Egyptian symbols, and that
the work of discovery was carried on and vastly extended by the Frenchman
Champollion, a little later, with the result that the firm foundations of the
modern science of Egyptology were laid. Subsequently such students as
Rosellini the Italian, Lepsius the German, and Wilkinson the Englishman,
entered the field, which in due course was cultivated by De Rouge in
France and Birch in England, and by such distinguished latter-day workers
as Chabas, Mariette, Maspero, Amelineau, and De Morgan among the
Frenchmen; Professor Petrie and Dr. Budge in England; and Brugsch Pasha

and Professor Erman in Germany, not to mention a large coterie of
somewhat less familiar names. These men working, some of them in the
field of practical exploration, some as students of the Egyptian language
and writing, have restored to us a tolerably precise knowledge of the history
of Egypt from the time of the first historical king, Mena, whose date is
placed at about the middle of the fifth century B.C. We know not merely the
names of most of the subsequent rulers, but some thing of the deeds of
many of them; and, what is vastly more important, we know, thanks to the
modern interpretation of the old literature, many things concerning the life
of the people, and in particular concerning their highest culture, their
methods of thought, and their scientific attainments, which might well have
been supposed to be past finding out. Nor has modern investigation halted
with the time of the first kings; the recent explorations of such
archaeologists as Amelineau, De Morgan, and Petrie have brought to light
numerous remains of what is now spoken of as the predynastic period—a
period when the inhabitants of the Nile Valley used implements of chipped
stone, when their pottery was made without the use of the potter's wheel,
and when they buried their dead in curiously cramped attitudes without
attempt at mummification. These aboriginal inhabitants of Egypt cannot
perhaps with strict propriety be spoken of as living within the historical
period, since we cannot date their relics with any accuracy. But they give us
glimpses of the early stages of civilization upon which the Egyptians of the
dynastic period were to advance.
It is held that the nascent civilization of these Egyptians of the Neolithic,
or late Stone Age, was overthrown by the invading hosts of a more highly
civilized race which probably came from the East, and which may have
been of a Semitic stock. The presumption is that this invading people
brought with it a knowledge of the arts of war and peace, developed or
adopted in its old home. The introduction of these arts served to bridge
somewhat suddenly, so far as Egypt is concerned, that gap between the
prehistoric and the historic stage of culture to which we have all along
referred. The essential structure of that bridge, let it now be clearly
understood, consisted of a single element. That element is the capacity to
make written records: a knowledge of the art of writing. Clearly understood,
it is this element of knowledge that forms the line bounding the historical
period. Numberless mementos are in existence that tell of the intellectual
activities of prehistoric man; such mementos as flint implements, pieces of

pottery, and fragments of bone, inscribed with pictures that may fairly be
spoken of as works of art; but so long as no written word accompanies these
records, so long as no name of king or scribe comes down to us, we feel
that these records belong to the domain of archaeology rather than to that of
history. Yet it must be understood all along that these two domains shade
one into the other and, it has already been urged, that the distinction
between them is one that pertains rather to modern scholarship than to the
development of civilization itself. Bearing this distinction still in mind, and
recalling that the historical period, which is to be the field of our
observation throughout the rest of our studies, extends for Egypt well back
into the fifth millennium B.C., let us briefly review the practical phases of
that civilization to which the Egyptian had attained before the beginning of
the dynastic period. Since theoretical science is everywhere linked with the
mechanical arts, this survey will give us a clear comprehension of the field
that lies open for the progress of science in the long stages of historical time
upon which we are just entering.
We may pass over such rudimentary advances in the direction of
civilization as are implied in the use of articulate language, the application
of fire to the uses of man, and the systematic making of dwellings of one
sort or another, since all of these are stages of progress that were reached
very early in the prehistoric period. What more directly concerns us is to
note that a really high stage of mechanical development had been reached
before the dawnings of Egyptian history proper. All manner of household
utensils were employed; the potter's wheel aided in the construction of a
great variety of earthen vessels; weaving had become a fine art, and
weapons of bronze, including axes, spears, knives, and arrow-heads, were
in constant use. Animals had long been domesticated, in particular the dog,
the cat, and the ox; the horse was introduced later from the East. The
practical arts of agriculture were practised almost as they are at the present
day in Egypt, there being, of course, the same dependence then as now
upon the inundations of the Nile.
As to government, the Egyptian of the first dynasty regarded his king as a
demi-god to be actually deified after his death, and this point of view was
not changed throughout the stages of later Egyptian history. In point of art,
marvellous advances upon the skill of the prehistoric man had been made,
probably in part under Asiatic influences, and that unique style of stilted yet
expressive drawing had come into vogue, which was to be remembered in

after times as typically Egyptian. More important than all else, our Egyptian
of the earliest historical period was in possession of the art of writing. He
had begun to make those specific records which were impossible to the man
of the Stone Age, and thus he had entered fully upon the way of historical
progress which, as already pointed out, has its very foundation in written
records. From now on the deeds of individual kings could find specific
record. It began to be possible to fix the chronology of remote events with
some accuracy; and with this same fixing of chronologies came the advent
of true history. The period which precedes what is usually spoken of as the
first dynasty in Egypt is one into which the present-day searcher is still able
to see but darkly. The evidence seems to suggest than an invasion of
relatively cultured people from the East overthrew, and in time supplanted,
the Neolithic civilization of the Nile Valley. It is impossible to date this
invasion accurately, but it cannot well have been later than the year 5000
B.C., and it may have been a great many centuries earlier than this. Be the
exact dates what they may, we find the Egyptian of the fifth millennium
B.C. in full possession of a highly organized civilization.
All subsequent ages have marvelled at the pyramids, some of which date
from about the year 4000 B.C., though we may note in passing that these
dates must not be taken too literally. The chronology of ancient Egypt
cannot as yet be fixed with exact accuracy, but the disagreements between
the various students of the subject need give us little concern. For our
present purpose it does not in the least matter whether the pyramids were
built three thousand or four thousand years before the beginning of our era.
It suffices that they date back to a period long antecedent to the beginnings
of civilization in Western Europe. They prove that the Egyptian of that early
day had attained a knowledge of practical mechanics which, even from the
twentieth-century point of view, is not to be spoken of lightly. It has
sometimes been suggested that these mighty pyramids, built as they are of
great blocks of stone, speak for an almost miraculous knowledge on the part
of their builders; but a saner view of the conditions gives no warrant for this
thought. Diodoras, the Sicilian, in his famous World's History, written about
the beginning of our era, explains the building of the pyramids by
suggesting that great quantities of earth were piled against the side of the
rising structure to form an inclined plane up which the blocks of stone were
dragged. He gives us certain figures, based, doubtless, on reports made to
him by Egyptian priests, who in turn drew upon the traditions of their

country, perhaps even upon written records no longer preserved. He says
that one hundred and twenty thousand men were employed in the
construction of the largest pyramid, and that, notwithstanding the size of
this host of workers, the task occupied twenty years. We must not place too
much dependence upon such figures as these, for the ancient historians are
notoriously given to exaggeration in recording numbers; yet we need not
doubt that the report given by Diodorus is substantially accurate in its main
outlines as to the method through which the pyramids were constructed. A
host of men putting their added weight and strength to the task, with the aid
of ropes, pulleys, rollers, and levers, and utilizing the principle of the
inclined plane, could undoubtedly move and elevate and place in position
the largest blocks that enter into the pyramids or—what seems even more
wonderful—the most gigantic obelisks, without the aid of any other kind of
mechanism or of any more occult power. The same hands could, as
Diodorus suggests, remove all trace of the debris of construction and leave
the pyramids and obelisks standing in weird isolation, as if sprung into
being through a miracle.
ASTRONOMICAL SCIENCE
It has been necessary to bear in mind these phases of practical
civilization because much that we know of the purely scientific attainments
of the Egyptians is based upon modern observation of their pyramids and
temples. It was early observed, for example, that the pyramids are
obviously oriented as regards the direction in which they face, in strict
accordance with some astronomical principle. Early in the nineteenth
century the Frenchman Biot made interesting studies in regard to this
subject, and a hundred years later, in our own time, Sir Joseph Norman
Lockyer, following up the work of various intermediary observers, has
given the subject much attention, making it the central theme of his work on
The Dawn of Astronomy.(1) Lockyer's researches make it clear that in the
main the temples of Egypt were oriented with reference to the point at
which the sun rises on the day of the summer solstice. The time of the
solstice had peculiar interest for the Egyptians, because it corresponded
rather closely with the time of the rising of the Nile. The floods of that river
appear with very great regularity; the on-rushing tide reaches the region of
Heliopolis and Memphis almost precisely on the day of the summer
solstice. The time varies at different stages of the river's course, but as the

civilization of the early dynasties centred at Memphis, observations made at
this place had widest vogue.
Considering the all-essential character of the Nile floods-without which
civilization would be impossible in Egypt—it is not strange that the time of
their appearance should be taken as marking the beginning of a new year.
The fact that their coming coincides with the solstice makes such a division
of the calendar perfectly natural. In point of fact, from the earliest periods
of which records have come down to us, the new year of the Egyptians
dates from the summer solstice. It is certain that from the earliest historical
periods the Egyptians were aware of the approximate length of the year. It
would be strange were it otherwise, considering the ease with which a
record of days could be kept from Nile flood to Nile flood, or from solstice
to solstice. But this, of course, applies only to an approximate count. There
is some reason to believe that in the earliest period the Egyptians made this
count only 360 days. The fact that their year was divided into twelve
months of thirty days each lends color to this belief; but, in any event, the
mistake was discovered in due time and a partial remedy was applied
through the interpolation of a "little month" of five days between the end of
the twelfth month and the new year. This nearly but not quite remedied the
matter. What it obviously failed to do was to take account of that additional
quarter of a day which really rounds out the actual year.
It would have been a vastly convenient thing for humanity had it chanced
that the earth had so accommodated its rotary motion with its speed of
transit about the sun as to make its annual flight in precisely 360 days.
Twelve lunar months of thirty days each would then have coincided exactly
with the solar year, and most of the complexities of the calendar, which
have so puzzled historical students, would have been avoided; but, on the
other hand, perhaps this very simplicity would have proved detrimental to
astronomical science by preventing men from searching the heavens as
carefully as they have done. Be that as it may, the complexity exists. The
actual year of three hundred and sixty-five and (about) one-quarter days
cannot be divided evenly into months, and some such expedient as the
intercalation of days here and there is essential, else the calendar will
become absolutely out of harmony with the seasons.
In the case of the Egyptians, the attempt at adjustment was made, as just
noted, by the introduction of the five days, constituting what the Egyptians

themselves termed "the five days over and above the year." These so-called
epagomenal days were undoubtedly introduced at a very early period.
Maspero holds that they were in use before the first Thinite dynasty, citing
in evidence the fact that the legend of Osiris explains these days as having
been created by the god Thot in order to permit Nuit to give birth to all her
children; this expedient being necessary to overcome a ban which had been
pronounced against Nuit, according to which she could not give birth to
children on any day of the year. But, of course, the five additional days do
not suffice fully to rectify the calendar. There remains the additional quarter
of a day to be accounted for. This, of course, amounts to a full day every
fourth year. We shall see that later Alexandrian science hit upon the
expedient of adding a day to every fourth year; an expedient which the
Julian calendar adopted and which still gives us our familiar leap-year. But,
unfortunately, the ancient Egyptian failed to recognize the need of this
additional day, or if he did recognize it he failed to act on his knowledge,
and so it happened that, starting somewhere back in the remote past with a
new year's day that coincided with the inundation of the Nile, there was a
constantly shifting maladjustment of calendar and seasons as time went on.
The Egyptian seasons, it should be explained, were three in number: the
season of the inundation, the season of the seed-time, and the season of the
harvest; each season being, of course, four months in extent. Originally, as
just mentioned, the season of the inundations began and coincided with the
actual time of inundation. The more precise fixing of new year's day was
accomplished through observation of the time of the so-called heliacal
rising of the dog-star, Sirius, which bore the Egyptian name Sothis. It
chances that, as viewed from about the region of Heliopolis, the sun at the
time of the summer solstice occupies an apparent position in the heavens
close to the dog-star. Now, as is well known, the Egyptians, seeing divinity
back of almost every phenomenon of nature, very naturally paid particular
reverence to so obviously influential a personage as the sun-god. In
particular they thought it fitting to do homage to him just as he was starting
out on his tour of Egypt in the morning; and that they might know the
precise moment of his coming, the Egyptian astronomer priests, perched on
the hill-tops near their temples, were wont to scan the eastern horizon with
reference to some star which had been observed to precede the solar
luminary. Of course the precession of the equinoxes, due to that axial
wobble in which our clumsy earth indulges, would change the apparent

position of the fixed stars in reference to the sun, so that the same star could
not do service as heliacal messenger indefinitely; but, on the other hand,
these changes are so slow that observations by many generations of
astronomers would be required to detect the shifting. It is believed by
Lockyer, though the evidence is not quite demonstrative, that the
astronomical observations of the Egyptians date back to a period when
Sothis, the dog-star, was not in close association with the sun on the
morning of the summer solstice. Yet, according to the calculations of Biot,
the heliacal rising of Sothis at the solstice was noted as early as the year
3285 B.C., and it is certain that this star continued throughout subsequent
centuries to keep this position of peculiar prestige. Hence it was that Sothis
came to be associated with Isis, one of the most important divinities of
Egypt, and that the day in which Sothis was first visible in the morning sky
marked the beginning of the new year; that day coinciding, as already
noted, with the summer solstice and with the beginning of the Nile flow.
But now for the difficulties introduced by that unreckoned quarter of a
day. Obviously with a calendar of 365 days only, at the end of four years,
the calendar year, or vague year, as the Egyptians came to call it, had gained
by one full day upon the actual solar year—that is to say, the heliacal rising
of Sothis, the dog-star, would not occur on new year's day of the faulty
calendar, but a day later. And with each succeeding period of four years the
day of heliacal rising, which marked the true beginning of the year—and
which still, of course, coincided with the inundation—would have fallen
another day behind the calendar. In the course of 120 years an entire month
would be lost; and in 480 years so great would become the shifting that the
seasons would be altogether misplaced; the actual time of inundations
corresponding with what the calendar registered as the seed-time, and the
actual seed-time in turn corresponding with the harvest-time of the calendar.
At first thought this seems very awkward and confusing, but in all
probability the effects were by no means so much so in actual practice. We
need go no farther than to our own experience to know that the names of
seasons, as of months and days, come to have in the minds of most of us a
purely conventional significance. Few of us stop to give a thought to the
meaning of the words January, February, etc., except as they connote certain
climatic conditions. If, then, our own calendar were so defective that in the
course of 120 years the month of February had shifted back to occupy the
position of the original January, the change would have been so gradual,

covering the period of two life-times or of four or five average generations,
that it might well escape general observation.
Each succeeding generation of Egyptians, then, may not improbably have
associated the names of the seasons with the contemporary climatic
conditions, troubling themselves little with the thought that in an earlier age
the climatic conditions for each period of the calendar were quite different.
We cannot well suppose, however, that the astronomer priests were
oblivious to the true state of things. Upon them devolved the duty of
predicting the time of the Nile flood; a duty they were enabled to perform
without difficulty through observation of the rising of the solstitial sun and
its Sothic messenger. To these observers it must finally have been apparent
that the shifting of the seasons was at the rate of one day in four years; this
known, it required no great mathematical skill to compute that this shifting
would finally effect a complete circuit of the calendar, so that after (4 X 365
=) 1460 years the first day of the calendar year would again coincide with
the heliacal rising of Sothis and with the coming of the Nile flood. In other
words, 1461 vague years or Egyptian calendar years Of 365 days each
correspond to 1460 actual solar years of 365 1/4 days each. This period,
measured thus by the heliacal rising of Sothis, is spoken of as the Sothic
cycle.
To us who are trained from childhood to understand that the year consists
of (approximately) 365 1/4 days, and to know that the calendar may be
regulated approximately by the introduction of an extra day every fourth
year, this recognition of the Sothic cycle seems simple enough. Yet if the
average man of us will reflect how little he knows, of his own knowledge,
of the exact length of the year, it will soon become evident that the
appreciation of the faults of the calendar and the knowledge of its periodical
adjustment constituted a relatively high development of scientific
knowledge on the part of the Egyptian astronomer. It may be added that
various efforts to reform the calendar were made by the ancient Egyptians,
but that they cannot be credited with a satisfactory solution of the problem;
for, of course, the Alexandrian scientists of the Ptolemaic period (whose
work we shall have occasion to review presently) were not Egyptians in any
proper sense of the word, but Greeks.
Since so much of the time of the astronomer priests was devoted to
observation of the heavenly bodies, it is not surprising that they should have

mapped out the apparent course of the moon and the visible planets in their
nightly tour of the heavens, and that they should have divided the stars of
the firmament into more or less arbitrary groups or constellations. That they
did so is evidenced by various sculptured representations of constellations
corresponding to signs of the zodiac which still ornament the ceilings of
various ancient temples. Unfortunately the decorative sense, which was
always predominant with the Egyptian sculptor, led him to take various
liberties with the distribution of figures in these representations of the
constellations, so that the inferences drawn from them as to the exact map
of the heavens as the Egyptians conceived it cannot be fully relied upon. It
appears, however, that the Egyptian astronomer divided the zodiac into
twenty-four decani, or constellations. The arbitrary groupings of figures,
with the aid of which these are delineated, bear a close resemblance to the
equally arbitrary outlines which we are still accustomed to use for the same
purpose.
IDEAS OF COSMOLOGY
In viewing this astronomical system of the Egyptians one cannot avoid
the question as to just what interpretation was placed upon it as regards the
actual mechanical structure of the universe. A proximal answer to the
question is supplied us with a good deal of clearness. It appears that the
Egyptian conceived the sky as a sort of tangible or material roof placed
above the world, and supported at each of its four corners by a column or
pillar, which was later on conceived as a great mountain. The earth itself
was conceived to be a rectangular box, longer from north to south than from
east to west; the upper surface of this box, upon which man lived, being
slightly concave and having, of course, the valley of the Nile as its centre.
The pillars of support were situated at the points of the compass; the
northern one being located beyond the Mediterranean Sea; the southern one
away beyond the habitable regions towards the source of the Nile, and the
eastern and western ones in equally inaccessible regions. Circling about the
southern side of the world was a great river suspended in mid-air on
something comparable to mountain cliffs; on which river the sun-god made
his daily course in a boat, fighting day by day his ever-recurring battle
against Set, the demon of darkness. The wide channel of this river enabled
the sun-god to alter his course from time to time, as he is observed to do; in
winter directing his bark towards the farther bank of the channel; in summer
gliding close to the nearer bank. As to the stars, they were similar lights,

suspended from the vault of the heaven; but just how their observed motion
of translation across the heavens was explained is not apparent. It is more
than probable that no one explanation was, universally accepted.
In explaining the origin of this mechanism of the heavens, the Egyptian
imagination ran riot. Each separate part of Egypt had its own hierarchy of
gods, and more or less its own explanations of cosmogony. There does not
appear to have been any one central story of creation that found universal
acceptance, any more than there was one specific deity everywhere
recognized as supreme among the gods. Perhaps the most interesting of the
cosmogonic myths was that which conceived that Nuit, the goddess of
night, had been torn from the arms of her husband, Sibu the earth-god, and
elevated to the sky despite her protests and her husband's struggles, there to
remain supported by her four limbs, which became metamorphosed into the
pillars, or mountains, already mentioned. The forcible elevation of Nuit had
been effected on the day of creation by a new god, Shu, who came forth
from the primeval waters. A painting on the mummy case of one
Betuhamon, now in the Turin Museum, illustrates, in the graphic manner so
characteristic of the Egyptians, this act of creation. As Maspero(2) points
out, the struggle of Sibu resulted in contorted attitudes to which the
irregularities of the earth's surface are to be ascribed.
In contemplating such a scheme of celestial mechanics as that just
outlined, one cannot avoid raising the question as to just the degree of
literalness which the Egyptians themselves put upon it. We know how
essentially eye-minded the Egyptian was, to use a modern psychological
phrase—that is to say, how essential to him it seemed that all his
conceptions should be visualized. The evidences of this are everywhere: all
his gods were made tangible; he believed in the immortality of the soul, yet
he could not conceive of such immortality except in association with an
immortal body; he must mummify the body of the dead, else, as he firmly
believed, the dissolution of the spirit would take place along with the
dissolution of the body itself. His world was peopled everywhere with
spirits, but they were spirits associated always with corporeal bodies; his
gods found lodgment in sun and moon and stars; in earth and water; in the
bodies of reptiles and birds and mammals. He worshipped all of these
things: the sun, the moon, water, earth, the spirit of the Nile, the ibis, the
cat, the ram, and apis the bull; but, so far as we can judge, his imagination
did not reach to the idea of an absolutely incorporeal deity. Similarly his

conception of the mechanism of the heavens must be a tangibly mechanical
one. He must think of the starry firmament as a substantial entity which
could not defy the law of gravitation, and which, therefore, must have the
same manner of support as is required by the roof of a house or temple. We
know that this idea of the materiality of the firmament found elaborate
expression in those later cosmological guesses which were to dominate the
thought of Europe until the time of Newton. We need not doubt, therefore,
that for the Egyptian this solid vault of the heavens had a very real
existence. If now and then some dreamer conceived the great bodies of the
firmament as floating in a less material plenum—and such iconoclastic
dreamers there are in all ages—no record of his musings has come down to
us, and we must freely admit that if such thoughts existed they were alien to
the character of the Egyptian mind as a whole.
While the Egyptians conceived the heavenly bodies as the abiding-place
of various of their deities, it does not appear that they practised astrology in
the later acceptance of that word. This is the more remarkable since the
conception of lucky and unlucky days was carried by the Egyptians to the
extremes of absurdity. "One day was lucky or unlucky," says Erman,(3)
"according as a good or bad mythological incident took place on that day.
For instance, the 1st of Mechir, on which day the sky was raised, and the
27th of Athyr, when Horus and, Set concluded peace together and divided
the world between them, were lucky days; on the other hand, the 14th of
Tybi, on which Isis and Nephthys mourned for Osiris, was an unlucky day.
With the unlucky days, which, fortunately, were less in number than the
lucky days, they distinguished different degrees of ill-luck. Some were very
unlucky, others only threatened ill-luck, and many, like the 17th and the
27th Choiakh, were partly good and partly bad according to the time of day.
Lucky days might, as a rule, be disregarded. At most it might be as well to
visit some specially renowned temple, or to 'celebrate a joyful day at home,'
but no particular precautions were really necessary; and, above all, it was
said, 'what thou also seest on the day is lucky.' It was quite otherwise with
the unlucky and dangerous days, which imposed so many and such great
limitations on people that those who wished to be prudent were always
obliged to bear them in mind when determining on any course of action.
Certain conditions were easy to carry out. Music and singing were to be
avoided on the 14th Tybi, the day of the mourning of Osiris, and no one was
allowed to wash on the 16th Tybi; whilst the name of Set might not be

pronounced on the 24th of Pharmuthi. Fish was forbidden on certain days;
and what was still more difficult in a country so rich in mice, on the 12th of
Tybi no mouse might be seen. The most tiresome prohibitions, however,
were those which occurred not infrequently, namely, those concerning work
and going out: for instance, four times in Paophi the people had to 'do
nothing at all,' and five times to sit the whole day or half the day in the
house; and the same rule had to be observed each month. It was impossible
to rejoice if a child was born on the 23d of Thoth; the parents knew it could
not live. Those born on the 20th of Choiakh would become blind, and those
born on the 3d of Choiakh, deaf."
CHARMS AND INCANTATIONS
Where such conceptions as these pertained, it goes without saying that
charms and incantations intended to break the spell of the unlucky omens
were equally prevalent. Such incantations consisted usually of the recitation
of certain phrases based originally, it would appear, upon incidents in the
history of the gods. The words which the god had spoken in connection
with some lucky incident would, it was thought, prove effective now in
bringing good luck to the human supplicant—that is to say, the magician
hoped through repeating the words of the god to exercise the magic power
of the god. It was even possible, with the aid of the magical observances,
partly to balk fate itself. Thus the person predestined through birth on an
unlucky day to die of a serpent bite might postpone the time of this fateful
visitation to extreme old age. The like uncertainty attached to those spells
which one person was supposed to be able to exercise over another. It was
held, for example, that if something belonging to an individual, such as a
lock of hair or a paring of the nails, could be secured and incorporated in a
waxen figure, this figure would be intimately associated with the
personality of that individual. An enemy might thus secure occult power
over one; any indignity practised upon the waxen figure would result in like
injury to its human prototype. If the figure were bruised or beaten, some
accident would overtake its double; if the image were placed over a fire, the
human being would fall into a fever, and so on. But, of course, such
mysterious evils as these would be met and combated by equally mysterious
processes; and so it was that the entire art of medicine was closely linked
with magical practices. It was not, indeed, held, according to Maspero, that
the magical spells of enemies were the sole sources of human ailments, but
one could never be sure to what extent such spells entered into the

affliction; and so closely were the human activities associated in the mind
of the Egyptian with one form or another of occult influences that purely
physical conditions were at a discount. In the later times, at any rate, the
physician was usually a priest, and there was a close association between
the material and spiritual phases of therapeutics. Erman(4) tells us that the
following formula had to be recited at the preparation of all medicaments:
"That Isis might make free, make free. That Isis might make Horus free
from all evil that his brother Set had done to him when he slew his father,
Osiris. O Isis, great enchantress, free me, release me from all evil red
things, from the fever of the god, and the fever of the goddess, from death
and death from pain, and the pain which comes over me; as thou hast freed,
as thou hast released thy son Horus, whilst I enter into the fire and come
forth from the water," etc. Again, when the invalid took the medicine, an
incantation had to be said which began thus: "Come remedy, come drive it
out of my heart, out of these limbs strong in magic power with the remedy."
He adds: "There may have been a few rationalists amongst the Egyptian
doctors, for the number of magic formulae varies much in the different
books. The book that we have specially taken for a foundation for this
account of Egyptian medicine—the great papyrus of the eighteenth dynasty
edited by Ebers(5)—contains, for instance, far fewer exorcisms than some
later writings with similar contents, probably because the doctor who
compiled this book of recipes from older sources had very little liking for
magic."
It must be understood, however—indeed, what has just been said implies
as much—that the physician by no means relied upon incantations alone; on
the contrary, he equipped himself with an astonishing variety of
medicaments. He had a particular fondness for what the modern physician
speaks of as a "shot-gun" prescription—one containing a great variety of
ingredients. Not only did herbs of many kinds enter into this, but such
substances as lizard's blood, the teeth of swine, putrid meat, the moisture
from pigs' ears, boiled horn, and numerous other even more repellent
ingredients. Whoever is familiar with the formulae employed by European
physicians even so recently as the eighteenth century will note a striking
similarity here. Erman points out that the modern Egyptian even of this day
holds closely to many of the practices of his remote ancestor. In particular,
the efficacy of the beetle as a medicinal agent has stood the test of ages of
practice. "Against all kinds of witchcraft," says an ancient formula, "a great

scarabaeus beetle; cut off his head and wings, boil him; put him in oil and
lay him out; then cook his head and wings, put them in snake fat, boil, and
let the patient drink the mixture." The modern Egyptian, says Erman, uses
almost precisely the same recipe, except that the snake fat is replaced by
modern oil.
In evidence of the importance which was attached to practical medicine
in the Egypt of an early day, the names of several physicians have come
down to us from an age which has preserved very few names indeed, save
those of kings. In reference to this Erman says(6): "We still know the names
of some of the early body physicians of this time; Sechmetna'eonch, 'chief
physician of the Pharaoh,' and Nesmenan his chief, the 'superintendent of
the physicians of the Pharaoh.' The priests also of the lioness-headed
goddess Sechmet seem to have been famed for their medical wisdom,
whilst the son of this goddess, the demi-god Imhotep, was in later times
considered to be the creator of medical knowledge. These ancient doctors of
the New Empire do not seem to have improved upon the older conceptions
about the construction of the human body."
As to the actual scientific attainments of the Egyptian physician, it is
difficult to speak with precision. Despite the cumbersome formulae and the
grotesque incantations, we need not doubt that a certain practical value
attended his therapeutics. He practised almost pure empiricism, however,
and certainly it must have been almost impossible to determine which ones,
if any, of the numerous ingredients of the prescription had real efficacy.
The practical anatomical knowledge of the physician, there is every
reason to believe, was extremely limited. At first thought it might seem that
the practice of embalming would have led to the custom of dissecting
human bodies, and that the Egyptians, as a result of this, would have
excelled in the knowledge of anatomy. But the actual results were rather the
reverse of this. Embalming the dead, it must be recalled, was a purely
religious observance. It took place under the superintendence of the priests,
but so great was the reverence for the human body that the priests
themselves were not permitted to make the abdominal incision which was a
necessary preliminary of the process. This incision, as we are informed by
both Herodotus(7) and Diodorus(8), was made by a special officer, whose
status, if we may believe the explicit statement of Diodorus, was quite
comparable to that of the modern hangman. The paraschistas, as he was

called, having performed his necessary but obnoxious function, with the aid
of a sharp Ethiopian stone, retired hastily, leaving the remaining processes
to the priests. These, however, confined their observations to the abdominal
viscera; under no consideration did they make other incisions in the body. It
follows, therefore, that their opportunity for anatomical observations was
most limited.
Since even the necessary mutilation inflicted on the corpse was regarded
with such horror, it follows that anything in the way of dissection for a less
sacred purpose was absolutely prohibited. Probably the same prohibition
extended to a large number of animals, since most of these were held sacred
in one part of Egypt or another. Moreover, there is nothing in what we know
of the Egyptian mind to suggest the probability that any Egyptian physician
would make extensive anatomical observations for the love of pure
knowledge. All Egyptian science is eminently practical. If we think of the
Egyptian as mysterious, it is because of the superstitious observances that
we everywhere associate with his daily acts; but these, as we have already
tried to make clear, were really based on scientific observations of a kind,
and the attempt at true inferences from these observations. But whether or
not the Egyptian physician desired anatomical knowledge, the results of his
inquiries were certainly most meagre. The essentials of his system had to do
with a series of vessels, alleged to be twenty-two or twenty-four in number,
which penetrated the head and were distributed in pairs to the various
members of the body, and which were vaguely thought of as carriers of
water, air, excretory fluids, etc. Yet back of this vagueness, as must not be
overlooked, there was an all-essential recognition of the heart as the central
vascular organ. The heart is called the beginning of all the members. Its
vessels, we are told, "lead to all the members; whether the doctor lays his
finger on the forehead, on the back of the head, on the hands, on the place
of the stomach (?), on the arms, or on the feet, everywhere he meets with
the heart, because its vessels lead to all the members."(9) This recognition
of the pulse must be credited to the Egyptian physician as a piece of
practical knowledge, in some measure off-setting the vagueness of his
anatomical theories.
ABSTRACT SCIENCE
But, indeed, practical knowledge was, as has been said over and over, the
essential characteristic of Egyptian science. Yet another illustration of this is

furnished us if we turn to the more abstract departments of thought and
inquire what were the Egyptian attempts in such a field as mathematics. The
answer does not tend greatly to increase our admiration for the Egyptian
mind. We are led to see, indeed, that the Egyptian merchant was able to
perform all the computations necessary to his craft, but we are forced to
conclude that the knowledge of numbers scarcely extended beyond this, and
that even here the methods of reckoning were tedious and cumbersome. Our
knowledge of the subject rests largely upon the so-called papyrus Rhind,
(10) which is a sort of mythological hand-book of the ancient Egyptians.
Analyzing this document, Professor Erman concludes that the knowledge of
the Egyptians was adequate to all practical requirements. Their mathematics
taught them "how in the exchange of bread for beer the respective value
was to be determined when converted into a quantity of corn; how to reckon
the size of a field; how to determine how a given quantity of corn would go
into a granary of a certain size," and like every-day problems. Yet they were
obliged to make some of their simple computations in a very roundabout
way. It would appear, for example, that their mental arithmetic did not
enable them to multiply by a number larger than two, and that they did not
reach a clear conception of complex fractional numbers. They did, indeed,
recognize that each part of an object divided into 10 pieces became 1/10 of
that object; they even grasped the idea of 2/3 this being a conception easily
visualized; but they apparently did not visualize such a conception as 3/10
except in the crude form of 1/10 plus 1/10 plus 1/10. Their entire idea of
division seems defective. They viewed the subject from the more
elementary stand-point of multiplication. Thus, in order to find out how
many times 7 is contained in 77, an existing example shows that the
numbers representing 1 times 7, 2 times 7, 4 times 7, 8 times 7 were set
down successively and various experimental additions made to find out
which sets of these numbers aggregated 77.

—1 7
—2 14
—4 28
—8 56

A line before the first, second, and fourth of these numbers indicated that
it is necessary to multiply 7 by 1 plus 2 plus 8—that is, by 11, in order to
obtain 77; that is to say, 7 goes 11 times in 77. All this seems very
cumbersome indeed, yet we must not overlook the fact that the process

which goes on in our own minds in performing such a problem as this is
precisely similar, except that we have learned to slur over certain of the
intermediate steps with the aid of a memorized multiplication table. In the
last analysis, division is only the obverse side of multiplication, and any one
who has not learned his multiplication table is reduced to some such
expedient as that of the Egyptian. Indeed, whenever we pass beyond the
range of our memorized multiplication table-which for most of us ends with
the twelves—the experimental character of the trial multiplication through
which division is finally effected does not so greatly differ from the
experimental efforts which the Egyptian was obliged to apply to smaller
numbers.
Despite his defective comprehension of fractions, the Egyptian was able
to work out problems of relative complexity; for example, he could
determine the answer of such a problem as this: a number together with its
fifth part makes 21; what is the number? The process by which the Egyptian
solved this problem seems very cumbersome to any one for whom a
rudimentary knowledge of algebra makes it simple, yet the method which
we employ differs only in that we are enabled, thanks to our hypothetical x,
to make a short cut, and the essential fact must not be overlooked that the
Egyptian reached a correct solution of the problem. With all due desire to
give credit, however, the fact remains that the Egyptian was but a crude
mathematician. Here, as elsewhere, it is impossible to admire him for any
high development of theoretical science. First, last, and all the time, he was
practical, and there is nothing to show that the thought of science for its
own sake, for the mere love of knowing, ever entered his head.
In general, then, we must admit that the Egyptian had not progressed far
in the hard way of abstract thinking. He worshipped everything about him
because he feared the result of failing to do so. He embalmed the dead lest
the spirit of the neglected one might come to torment him. Eye-minded as
he was, he came to have an artistic sense, to love decorative effects. But he
let these always take precedence over his sense of truth; as, for example,
when he modified his lists of kings at Abydos to fit the space which the
architect had left to be filled; he had no historical sense to show to him that
truth should take precedence over mere decoration. And everywhere he
lived in the same happy-go-lucky way. He loved personal ease, the
pleasures of the table, the luxuries of life, games, recreations, festivals. He
took no heed for the morrow, except as the morrow might minister to his

personal needs. Essentially a sensual being, he scarcely conceived the
meaning of the intellectual life in the modern sense of the term. He had
perforce learned some things about astronomy, because these were
necessary to his worship of the gods; about practical medicine, because this
ministered to his material needs; about practical arithmetic, because this
aided him in every-day affairs. The bare rudiments of an historical science
may be said to be crudely outlined in his defective lists of kings. But
beyond this he did not go. Science as science, and for its own sake, was
unknown to him. He had gods for all material functions, and festivals in
honor of every god; but there was no goddess of mere wisdom in his
pantheon. The conception of Minerva was reserved for the creative genius
of another people.

III. SCIENCE OF BABYLONIA AND ASSYRIA
Throughout classical antiquity Egyptian science was famous. We know
that Plato spent some years in Egypt in the hope of penetrating the alleged
mysteries of its fabled learning; and the story of the Egyptian priest who
patronizingly assured Solon that the Greeks were but babes was quoted
everywhere without disapproval. Even so late as the time of Augustus, we
find Diodorus, the Sicilian, looking back with veneration upon the Oriental
learning, to which Pliny also refers with unbounded respect. From what we
have seen of Egyptian science, all this furnishes us with a somewhat
striking commentary upon the attainments of the Greeks and Romans
themselves. To refer at length to this would be to anticipate our purpose;
what now concerns us is to recall that all along there was another nation, or
group of nations, that disputed the palm for scientific attainments. This
group of nations found a home in the valley of the Tigris and Euphrates.
Their land was named Mesopotamia by the Greeks, because a large part of
it lay between the two rivers just mentioned. The peoples themselves are
familiar to every one as the Babylonians and the Assyrians. These peoples
were of Semitic stock—allied, therefore, to the ancient Hebrews and
Phoenicians and of the same racial stem with the Arameans and Arabs.
The great capital of the Babylonians during the later period of their
history was the famed city of Babylon itself; the most famous capital of the
Assyrians was Nineveh, that city to which, as every Bible-student will
recall, the prophet Jonah was journeying when he had a much-exploited
experience, the record of which forms no part of scientific annals. It was the
kings of Assyria, issuing from their palaces in Nineveh, who dominated the
civilization of Western Asia during the heyday of Hebrew history, and
whose deeds are so frequently mentioned in the Hebrew chronicles. Later
on, in the year 606 B.C., Nineveh was overthrown by the Medes(1) and
Babylonians. The famous city was completely destroyed, never to be
rebuilt. Babylon, however, though conquered subsequently by Cyrus and
held in subjection by Darius,(2) the Persian kings, continued to hold sway
as a great world-capital for some centuries. The last great historical event

that occurred within its walls was the death of Alexander the Great, which
took place there in the year 322 B.C.
In the time of Herodotus the fame of Babylon was at its height, and the
father of history has left us a most entertaining account of what he saw
when he visited the wonderful capital. Unfortunately, Herodotus was not a
scholar in the proper acceptance of the term. He probably had no inkling of
the Babylonian language, so the voluminous records of its literature were
entirely shut off from his observation. He therefore enlightens us but little
regarding the science of the Babylonians, though his observations on their
practical civilization give us incidental references of no small importance.
Somewhat more detailed references to the scientific attainments of the
Babylonians are found in the fragments that have come down to us of the
writings of the great Babylonian historian, Berosus,(3) who was born in
Babylon about 330 B.C., and who was, therefore, a contemporary of
Alexander the Great. But the writings of Berosus also, or at least such parts
of them as have come down to us, leave very much to be desired in point of
explicitness. They give some glimpses of Babylonian history, and they
detail at some length the strange mythical tales of creation that entered into
the Babylonian conception of cosmogony—details which find their
counterpart in the allied recitals of the Hebrews. But taken all in all, the
glimpses of the actual state of Chaldean(4) learning, as it was commonly
called, amounted to scarcely more than vague wonder-tales. No one really
knew just what interpretation to put upon these tales until the explorers of
the nineteenth century had excavated the ruins of the Babylonian and
Assyrian cities, bringing to light the relics of their wonderful civilization.
But these relics fortunately included vast numbers of written documents,
inscribed on tablets, prisms, and cylinders of terra-cotta. When nineteenth-
century scholarship had penetrated the mysteries of the strange script, and
ferreted out the secrets of an unknown tongue, the world at last was in
possession of authentic records by which the traditions regarding the
Babylonians and Assyrians could be tested. Thanks to these materials, a
new science commonly spoken of as Assyriology came into being, and a
most important chapter of human history was brought to light. It became
apparent that the Greek ideas concerning Mesopotamia, though vague in the
extreme, were founded on fact. No one any longer questions that the
Mesopotamian civilization was fully on a par with that of Egypt; indeed, it
is rather held that superiority lay with the Asiatics. Certainly, in point of

purely scientific attainments, the Babylonians passed somewhat beyond
their Egyptian competitors. All the evidence seems to suggest also that the
Babylonian civilization was even more ancient than that of Egypt. The
precise dates are here in dispute; nor for our present purpose need they
greatly concern us. But the Assyrio-Babylonian records have much greater
historical accuracy as regards matters of chronology than have the
Egyptian, and it is believed that our knowledge of the early Babylonian
history is carried back, with some certainty, to King Sargon of Agade,(5) for
whom the date 3800 B.C. is generally accepted; while somewhat vaguer
records give us glimpses of periods as remote as the sixth, perhaps even the
seventh or eighth millenniums before our era.
At a very early period Babylon itself was not a capital and Nineveh had
not come into existence. The important cities, such as Nippur and Shirpurla,
were situated farther to the south. It is on the site of these cities that the
recent excavations have been made, such as those of the University of
Pennsylvania expeditions at Nippur,(6) which are giving us glimpses into
remoter recesses of the historical period.
Even if we disregard the more problematical early dates, we are still
concerned with the records of a civilization extending unbroken throughout
a period of about four thousand years; the actual period is in all probability
twice or thrice that. Naturally enough, the current of history is not an
unbroken stream throughout this long epoch. It appears that at least two
utterly different ethnic elements are involved. A preponderance of evidence
seems to show that the earliest civilized inhabitants of Mesopotamia were
not Semitic, but an alien race, which is now commonly spoken of as
Sumerian. This people, of whom we catch glimpses chiefly through the
records of its successors, appears to have been subjugated or overthrown by
Semitic invaders, who, coming perhaps from Arabia (their origin is in
dispute), took possession of the region of the Tigris and Euphrates, learned
from the Sumerians many of the useful arts, and, partly perhaps because of
their mixed lineage, were enabled to develop the most wonderful
civilization of antiquity. Could we analyze the details of this civilization
from its earliest to its latest period we should of course find the same
changes which always attend racial progress and decay. We should then be
able, no doubt, to speak of certain golden epochs and their periods of
decline. To a certain meagre extent we are able to do this now. We know, for
example, that King Khammurabi, who lived about 2200 B.C., was a great

law-giver, the ancient prototype of Justinian; and the epochs of such
Assyrian kings as Sargon II., Asshurnazirpal, Sennacherib, and
Asshurbanapal stand out with much distinctness. Yet, as a whole, the record
does not enable us to trace with clearness the progress of scientific thought.
At best we can gain fewer glimpses in this direction than in almost any
other, for it is the record of war and conquest rather than of the peaceful arts
that commanded the attention of the ancient scribe. So in dealing with the
scientific achievements of these peoples, we shall perforce consider their
varied civilizations as a unity, and attempt, as best we may, to summarize
their achievements as a whole. For the most part, we shall not attempt to
discriminate as to what share in the final product was due to Sumerian,
what to Babylonian, and what to Assyrian. We shall speak of Babylonian
science as including all these elements; and drawing our information chiefly
from the relatively late Assyrian and Babylonian sources, which, therefore,
represent the culminating achievements of all these ages of effort, we shall
attempt to discover what was the actual status of Mesopotamian science at
its climax. In so far as we succeed, we shall be able to judge what scientific
heritage Europe received from the Orient; for in the records of Babylonian
science we have to do with the Eastern mind at its best. Let us turn to the
specific inquiry as to the achievements of the Chaldean scientist whose
fame so dazzled the eyes of his contemporaries of the classic world.
BABYLONIAN ASTRONOMY
Our first concern naturally is astronomy, this being here, as in Egypt, the
first-born and the most important of the sciences. The fame of the Chaldean
astronomer was indeed what chiefly commanded the admiration of the
Greeks, and it was through the results of astronomical observations that
Babylonia transmitted her most important influences to the Western world.
"Our division of time is of Babylonian origin," says Hornmel;(7) "to
Babylonia we owe the week of seven days, with the names of the planets
for the days of the week, and the division into hours and months." Hence
the almost personal interest which we of to-day must needs feel in the
efforts of the Babylonian star-gazer.
It must not be supposed, however, that the Chaldean astronomer had
made any very extraordinary advances upon the knowledge of the Egyptian
"watchers of the night." After all, it required patient observation rather than
any peculiar genius in the observer to note in the course of time such broad

astronomical conditions as the regularity of the moon's phases, and the
relation of the lunar periods to the longer periodical oscillations of the sun.
Nor could the curious wanderings of the planets escape the attention of
even a moderately keen observer. The chief distinction between the
Chaldean and Egyptian astronomers appears to have consisted in the
relative importance they attached to various of the phenomena which they
both observed. The Egyptian, as we have seen, centred his attention upon
the sun. That luminary was the abode of one of his most important gods.
His worship was essentially solar. The Babylonian, on the other hand,
appears to have been peculiarly impressed with the importance of the moon.
He could not, of course, overlook the attention-compelling fact of the solar
year; but his unit of time was the lunar period of thirty days, and his year
consisted of twelve lunar periods, or 360 days. He was perfectly aware,
however, that this period did not coincide with the actual year; but the
relative unimportance which he ascribed to the solar year is evidenced by
the fact that he interpolated an added month to adjust the calendar only once
in six years. Indeed, it would appear that the Babylonians and Assyrians did
not adopt precisely the same method of adjusting the calendar, since the
Babylonians had two intercular months called Elul and Adar, whereas the
Assyrians had only a single such month, called the second Adar.(8) (The
Ve'Adar of the Hebrews.) This diversity further emphasizes the fact that it
was the lunar period which received chief attention, the adjustment of this
period with the solar seasons being a necessary expedient of secondary
importance. It is held that these lunar periods have often been made to do
service for years in the Babylonian computations and in the allied
computations of the early Hebrews. The lives of the Hebrew patriarchs, for
example, as recorded in the Bible, are perhaps reckoned in lunar "years."
Divided by twelve, the "years" of Methuselah accord fairly with the usual
experience of mankind.
Yet, on the other hand, the convenience of the solar year in computing
long periods of time was not unrecognized, since this period is utilized in
reckoning the reigns of the Assyrian kings. It may be added that the reign of
a king "was not reckoned from the day of his accession, but from the
Assyrian new year's day, either before or after the day of accession. There
does not appear to have been any fixed rule as to which new year's day
should be chosen; but from the number of known cases, it appears to have
been the general practice to count the reigning years from the new year's

day nearest the accession, and to call the period between the accession day
and the first new year's day 'the beginning of the reign,' when the year from
the new year's day was called the first year, and the following ones were
brought successively from it. Notwithstanding, in the dates of several
Assyrian and Babylonian sovereigns there are cases of the year of accession
being considered as the first year, thus giving two reckonings for the reigns
of various monarchs, among others, Shalmaneser, Sennacherib,
Nebuchadrezzar."(9) This uncertainty as to the years of reckoning again
emphasizes the fact that the solar year did not have for the Assyrian
chronology quite the same significance that it has for us.
The Assyrian month commenced on the evening when the new moon was
first observed, or, in case the moon was not visible, the new month started
thirty days after the last month. Since the actual lunar period is about
twenty-nine and one-half days, a practical adjustment was required between
the months themselves, and this was probably effected by counting alternate
months as Only 29 days in length. Mr. R. Campbell Thompson(10) is led by
his studies of the astrological tablets to emphasize this fact. He believes that
"the object of the astrological reports which related to the appearance of the
moon and sun was to help determine and foretell the length of the lunar
month." Mr. Thompson believes also that there is evidence to show that the
interculary month was added at a period less than six years. In point of fact,
it does not appear to be quite clearly established as to precisely how the
adjustment of days with the lunar months, and lunar months with the solar
year, was effected. It is clear, however, according to Smith, "that the first 28
days of every month were divided into four weeks of seven days each; the
seventh, fourteenth, twenty-first, twenty-eighth days respectively being
Sabbaths, and that there was a general prohibition of work on these days."
Here, of course, is the foundation of the Hebrew system of Sabbatical days
which we have inherited. The sacredness of the number seven itself—the
belief in which has not been quite shaken off even to this day—was
deduced by the Assyrian astronomer from his observation of the seven
planetary bodies—namely, Sin (the moon), Samas (the sun), Umunpawddu
(Jupiter), Dilbat (Venus), Kaimanu (Saturn), Gudud (Mercury), Mustabarru-
mutanu (Mars).(11) Twelve lunar periods, making up approximately the
solar year, gave peculiar importance to the number twelve also. Thus the
zodiac was divided into twelve signs which astronomers of all subsequent
times have continued to recognize; and the duodecimal system of counting

took precedence with the Babylonian mathematicians over the more
primitive and, as it seems to us, more satisfactory decimal system.
Another discrepancy between the Babylonian and Egyptian years appears
in the fact that the Babylonian new year dates from about the period of the
vernal equinox and not from the solstice. Lockyer associates this with the
fact that the periodical inundation of the Tigris and Euphrates occurs about
the equinoctial period, whereas, as we have seen, the Nile flood comes at
the time of the solstice. It is but natural that so important a phenomenon as
the Nile flood should make a strong impression upon the minds of a people
living in a valley. The fact that occasional excessive inundations have led to
most disastrous results is evidenced in the incorporation of stories of the
almost total destruction of mankind by such floods among the myth tales of
all peoples who reside in valley countries. The flooding of the Tigris and
Euphrates had not, it is true, quite the same significance for the
Mesopotamians that the Nile flood had for the Egyptians. Nevertheless it
was a most important phenomenon, and may very readily be imagined to
have been the most tangible index to the seasons. But in recognizing the
time of the inundations and the vernal equinox, the Assyrians did not
dethrone the moon from its accustomed precedence, for the year was
reckoned as commencing not precisely at the vernal equinox, but at the new
moon next before the equinox.
ASTROLOGY
Beyond marking the seasons, the chief interests that actuated the
Babylonian astronomer in his observations were astrological. After quoting
Diodorus to the effect that the Babylonian priests observed the position of
certain stars in order to cast horoscopes, Thompson tells us that from a very
early day the very name Chaldean became synonymous with magician. He
adds that "from Mesopotamia, by way of Greece and Rome, a certain
amount of Babylonian astrology made its way among the nations of the
west, and it is quite probable that many superstitions which we commonly
record as the peculiar product of western civilization took their origin from
those of the early dwellers on the alluvial lands of Mesopotamia. One
Assurbanipal, king of Assyria B.C. 668-626, added to the royal library at
Nineveh his contribution of tablets, which included many series of
documents which related exclusively to the astrology of the ancient
Babylonians, who in turn had borrowed it with modifications from the

Sumerian invaders of the country. Among these must be mentioned the
series which was commonly called 'the Day of Bel,' and which was decreed
by the learned to have been written in the time of the great Sargon I., king
of Agade, 3800 B.C. With such ancient works as these to guide them, the
profession of deducing omens from daily events reached such a pitch of
importance in the last Assyrian Empire that a system of making periodical
reports came into being. By these the king was informed of all the
occurrences in the heavens and on earth, and the results of astrological
studies in respect to after events. The heads of the astrological profession
were men of high rank and position, and their office was hereditary. The
variety of information contained in these reports is best gathered from the
fact that they were sent from cities as far removed from each other as Assur
in the north and Erech in the south, and it can only be assumed that they
were despatched by runners, or men mounted on swift horses. As reports
also came from Dilbat, Kutba, Nippur, and Bursippa, all cities of ancient
foundation, the king was probably well acquainted with the general course
of events in his empire."(12)
From certain passages in the astrological tablets, Thompson draws the
interesting conclusion that the Chaldean astronomers were acquainted with
some kind of a machine for reckoning time. He finds in one of the tablets a
phrase which he interprets to mean measure-governor, and he infers from
this the existence of a kind of a calculator. He calls attention also to the fact
that Sextus Empiricus(13) states that the clepsydra was known to the
Chaldeans, and that Herodotus asserts that the Greeks borrowed certain
measures of time from the Babylonians. He finds further corroboration in
the fact that the Babylonians had a time-measure by which they divided the
day and the night; a measure called kasbu, which contained two hours. In a
report relating to the day of the vernal equinox, it is stated that there are six
kasbu of the day and six kasbu of the night.
While the astrologers deduced their omens from all the celestial bodies
known to them, they chiefly gave attention to the moon, noting with great
care the shape of its horns, and deducing such a conclusion as that "if the
horns are pointed the king will overcome whatever he goreth," and that
"when the moon is low at its appearance, the submission (of the people) of
a far country will come."(14) The relations of the moon and sun were a
source of constant observation, it being noted whether the sun and moon
were seen together above the horizon; whether one set as the other rose, and

the like. And whatever the phenomena, there was always, of course, a direct
association between such phenomena and the well-being of human kind—in
particular the king, at whose instance, and doubtless at whose expense, the
observations were carried out.
From omens associated with the heavenly bodies it is but a step to omens
based upon other phenomena of nature, and we, shall see in a moment that
the Babylonian prophets made free use of their opportunities in this
direction also. But before we turn from the field of astronomy, it will be
well to inform ourselves as to what system the Chaldean astronomer had
invented in explanation of the mechanics of the universe. Our answer to this
inquiry is not quite as definite as could be desired, the vagueness of the
records, no doubt, coinciding with the like vagueness in the minds of the
Chaldeans themselves. So far as we can interpret the somewhat mystical
references that have come down to us, however, the Babylonian cosmology
would seem to have represented the earth as a circular plane surrounded by
a great circular river, beyond which rose an impregnable barrier of
mountains, and resting upon an infinite sea of waters. The material vault of
the heavens was supposed to find support upon the outlying circle of
mountains. But the precise mechanism through which the observed
revolution of the heavenly bodies was effected remains here, as with the
Egyptian cosmology, somewhat conjectural. The simple fact would appear
to be that, for the Chaldeans as for the Egyptians, despite their most careful
observations of the tangible phenomena of the heavens, no really
satisfactory mechanical conception of the cosmos was attainable. We shall
see in due course by what faltering steps the European imagination
advanced from the crude ideas of Egypt and Babylonia to the relatively
clear vision of Newton and Laplace.
CHALDEAN MAGIC
We turn now from the field of the astrologer to the closely allied province
of Chaldean magic—a province which includes the other; which, indeed, is
so all-encompassing as scarcely to leave any phase of Babylonian thought
outside its bounds.
The tablets having to do with omens, exorcisms, and the like magic
practices make up an astonishingly large proportion of the Babylonian
records. In viewing them it is hard to avoid the conclusion that the
superstitions which they evidenced absolutely dominated the life of the

Babylonians of every degree. Yet it must not be forgotten that the greatest
inconsistencies everywhere exist between the superstitious beliefs of a
people and the practical observances of that people. No other problem is so
difficult for the historian as that which confronts him when he endeavors to
penetrate the mysteries of an alien religion; and when, as in the present
case, the superstitions involved have been transmitted from generation to
generation, their exact practical phases as interpreted by any particular
generation must be somewhat problematical. The tablets upon which our
knowledge of these omens is based are many of them from the libraries of
the later kings of Nineveh; but the omens themselves are, in such cases,
inscribed in the original Accadian form in which they have come down
from remote ages, accompanied by an Assyrian translation. Thus the
superstitions involved had back of them hundreds of years, even thousands
of years, of precedent; and we need not doubt that the ideas with which they
are associated were interwoven with almost every thought and deed of the
life of the people. Professor Sayce assures us that the Assyrians and
Babylonians counted no fewer than three hundred spirits of heaven, and six
hundred spirits of earth. "Like the Jews of the Talmud," he says, "they
believed that the world was swarming with noxious spirits, who produced
the various diseases to which man is liable, and might be swallowed with
the food and drink which support life." Fox Talbot was inclined to believe
that exorcisms were the exclusive means used to drive away the tormenting
spirits. This seems unlikely, considering the uniform association of drugs
with the magical practices among their people. Yet there is certainly a
strange silence of the tablets in regard to medicine. Talbot tells us that
sometimes divine images were brought into the sick-chamber, and written
texts taken from holy books were placed on the walls and bound around the
sick man's members. If these failed, recourse was had to the influence of the
mamit, which the evil powers were unable to resist. On a tablet, written in
the Accadian language only, the Assyrian version being taken, however, was
found the following:

1. Take a white cloth. In it place the mamit,
2. in the sick man's right hand.
3. Take a black cloth,
4. wrap it around his left hand.
5. Then all the evil spirits (a long list of them is given)
6. and the sins which he has committed
7. shall quit their hold of him
8. and shall never return.

The symbolism of the black cloth in the left hand seems evident. The
dying man repents of his former evil deeds, and he puts his trust in holiness,
symbolized by the white cloth in his right hand. Then follow some obscure
lines about the spirits:

1. Their heads shall remove from his head.
2. Their heads shall let go his hands.
3. Their feet shall depart from his feet.

Which perhaps may be explained thus: we learn from another tablet that
the various classes of evil spirits troubled different parts of the body; some
injured the head, some the hands and the feet, etc., therefore the passage
before may mean "the spirits whose power is over the hand shall loose their
hands from his," etc. "But," concludes Talbot, "I can offer no decided
opinion upon such obscure points of their superstition."(15)
In regard to evil spirits, as elsewhere, the number seven had a peculiar
significance, it being held that that number of spirits might enter into a man
together. Talbot has translated(16) a "wild chant" which he names "The
Song of the Seven Spirits."

1. There are seven! There are seven!
2. In the depths of the ocean there are seven!
3. In the heights of the heaven there are seven!
4. In the ocean stream in a palace they were born.
5. Male they are not: female they are not!
6. Wives they have not! Children are not born to them!
7. Rules they have not! Government they know not!
8. Prayers they hear not!
9. There are seven! There are seven! Twice over there are
seven!

The tablets make frequent allusion to these seven spirits. One starts thus:

1. The god (—-) shall stand by his bedside;
2. These seven evil spirits he shall root out and shall expel
them from his body, 3. and these seven shall never return to the sick man
again.(17)

Altogether similar are the exorcisms intended to ward off disease.
Professor Sayce has published translations of some of these.(18) Each of
these ends with the same phrase, and they differ only in regard to the
particular maladies from which freedom is desired. One reads:
"From wasting, from want of health, from the evil spirit of the ulcer, from
the spreading quinsy of the gullet, from the violent ulcer, from the noxious

ulcer, may the king of heaven preserve, may the king of earth preserve."
Another is phrased thus:
"From the cruel spirit of the head, from the strong spirit of the head, from
the head spirit that departs not, from the head spirit that comes not forth,
from the head spirit that will not go, from the noxious head spirit, may the
king of heaven preserve, may the king of earth preserve."
As to omens having to do with the affairs of everyday life the number is
legion. For example, Moppert has published, in the Journal Asiatique,(19)
the translation of a tablet which contains on its two sides several scores of
birth-portents, a few of which maybe quoted at random:
"When a woman bears a child and it has the ears of a lion, a strong king
is in the country." "When a woman bears a child and it has a bird's beak,
that country is oppressed." "When a woman bears a child and its right hand
is wanting, that country goes to destruction." "When a woman bears a child
and its feet are wanting, the roads of the country are cut; that house is
destroyed." "When a woman bears a child and at the time of its birth its
beard is grown, floods are in the country." "When a woman bears a child
and at the time of its birth its mouth is open and speaks, there is pestilence
in the country, the Air-god inundates the crops of the country, injury in the
country is caused."
Some of these portents, it will be observed, are not in much danger of
realization, and it is curious to surmise by what stretch of the imagination
they can have been invented. There is, for example, on the same tablet just
quoted, one reference which assures us that "when a sheep bears a lion the
forces march multitudinously; the king has not a rival." There are other
omens, however, that are so easy of realization as to lead one to suppose
that any Babylonian who regarded all the superstitious signs must have
been in constant terror. Thus a tablet translated by Professor Sayce(20)
gives a long list of omens furnished by dogs, in which we are assured that:

1. If a yellow dog enters into the palace, exit from that
palace will be baleful.
2. If a dog to the palace goes, and on a throne lies down, that
palace is burned.
3. If a black dog into a temple enters, the foundation of that
temple is not stable.
4. If female dogs one litter bear, destruction to the city.

It is needless to continue these citations, since they but reiterate endlessly
the same story. It is interesting to recall, however, that the observations of
animate nature, which were doubtless superstitious in their motive, had
given the Babylonians some inklings of a knowledge of classification. Thus,
according to Menant,(21) some of the tablets from Nineveh, which are
written, as usual, in both the Sumerian and Assyrian languages, and which,
therefore, like practically all Assyrian books, draw upon the knowledge of
old Babylonia, give lists of animals, making an attempt at classification.
The dog, lion, and wolf are placed in one category; the ox, sheep, and goat
in another; the dog family itself is divided into various races, as the
domestic dog, the coursing dog, the small dog, the dog of Elan, etc. Similar
attempts at classification of birds are found. Thus, birds of rapid flight, sea-
birds, and marsh-birds are differentiated. Insects are classified according to
habit; those that attack plants, animals, clothing, or wood. Vegetables seem
to be classified according to their usefulness. One tablet enumerates the
uses of wood according to its adaptability for timber-work of palaces, or
construction of vessels, the making of implements of husbandry, or even
furniture. Minerals occupy a long series in these tablets. They are classed
according to their qualities, gold and silver occupying a division apart;
precious stones forming another series. Our Babylonians, then, must be
credited with the development of a rudimentary science of natural history.
BABYLONIAN MEDICINE
We have just seen that medical practice in the Babylonian world was
strangely under the cloud of superstition. But it should be understood that
our estimate, through lack of correct data, probably does much less than
justice to the attainments of the physician of the time. As already noted, the
existing tablets chance not to throw much light on the subject. It is known,
however, that the practitioner of medicine occupied a position of some,
authority and responsibility. The proof of this is found in the clauses
relating to the legal status of the physician which are contained in the now
famous code(22) of the Babylonian King Khamurabi, who reigned about
2300 years before our era. These clauses, though throwing no light on the
scientific attainments of the physician of the period, are too curious to be
omitted. They are clauses 215 to 227 of the celebrated code, and are as
follows:

215. If a doctor has treated a man for a severe wound with a lancet of
bronze and has cured the man, or has opened a tumor with a bronze lancet
and has cured the man's eye, he shall receive ten shekels of silver.
216. If it was a freedman, he shall receive five shekels of silver.
217. If it was a man's slave, the owner of the slave shall give the doctor
two shekels of silver.
218. If a physician has treated a free-born man for a severe wound with a
lancet of bronze and has caused the man to die, or has opened a tumor of
the man with a lancet of bronze and has destroyed his eye, his hands one
shall cut off.
219. If the doctor has treated the slave of a freedman for a severe wound
with a bronze lancet and has caused him to die, he shall give back slave for
slave.
220. If he has opened his tumor with a bronze lancet and has ruined his
eye, he shall pay the half of his price in money.
221. If a doctor has cured the broken limb of a man, or has healed his
sick body, the patient shall pay the doctor five shekels of silver.
222. If it was a freedman, he shall give three shekels of silver.
223. If it was a man's slave, the owner of the slave shall give two shekels
of silver to the doctor.
224. If the doctor of oxen and asses has treated an ox or an ass for a
grave wound and has cured it, the owner of the ox or the ass shall give to
the doctor as his pay one-sixth of a shekel of silver.
225. If he has treated an ox or an ass for a severe wound and has caused
its death, he shall pay one-fourth of its price to the owner of the ox or the
ass.
226. If a barber-surgeon, without consent of the owner of a slave, has
branded the slave with an indelible mark, one shall cut off the hands of that
barber.
227. If any one deceive the surgeon-barber and make him brand a slave
with an indelible mark, one shall kill that man and bury him in his house.
The barber shall swear, "I did not mark him wittingly," and he shall be
guiltless.
ESTIMATES OF BABYLONIAN SCIENCE

Before turning from the Oriental world it is perhaps worth while to
attempt to estimate somewhat specifically the world-influence of the name,
Babylonian science. Perhaps we cannot better gain an idea as to the
estimate put upon that science by the classical world than through a
somewhat extended quotation from a classical author. Diodorus Siculus,
who, as already noted, lived at about the time of Augustus, and who,
therefore, scanned in perspective the entire sweep of classical Greek history,
has left us a striking summary which is doubly valuable because of its
comparisons of Babylonian with Greek influence. Having viewed the
science of Babylonia in the light of the interpretations made possible by the
recent study of original documents, we are prepared to draw our own
conclusions from the statements of the Greek historian. Here is his estimate
in the words of the quaint translation made by Philemon Holland in the year
1700:(23)
"They being the most ancient Babylonians, hold the same station and
dignity in the Common-wealth as the Egyptian Priests do in Egypt: For
being deputed to Divine Offices, they spend all their Time in the study of
Philosophy, and are especially famous for the Art of Astrology. They are
mightily given to Divination, and foretel future Events, and imploy
themselves either by Purifications, Sacrifices, or other Inchantments to
avert Evils, or procure good Fortune and Success. They are skilful likewise
in the Art of Divination, by the flying of Birds, and interpreting of Dreams
and Prodigies: And are reputed as true Oracles (in declaring what will come
to pass) by their exact and diligent viewing the Intrals of the Sacrifices. But
they attain not to this Knowledge in the same manner as the Grecians do;
for the Chaldeans learn it by Tradition from their Ancestors, the Son from
the Father, who are all in the mean time free from all other publick Offices
and Attendances; and because their Parents are their Tutors, they both learn
every thing without Envy, and rely with more confidence upon the truth of
what is taught them; and being train'd up in this Learning, from their very
Childhood, they become most famous Philosophers, (that Age being most
capable of Learning, wherein they spend much of their time). But the
Grecians for the most part come raw to this study, unfitted and unprepar'd,
and are long before they attain to the Knowledge of this Philosophy: And
after they have spent some small time in this Study, they are many times
call'd off and forc'd to leave it, in order to get a Livelihood and Subsistence.
And although some, few do industriously apply themselves to Philosophy,

yet for the sake of Gain, these very Men are opinionative, and ever and
anon starting new and high Points, and never fix in the steps of their
Ancestors. But the Barbarians keeping constantly close to the same thing,
attain to a perfect and distinct Knowledge in every particular.
"But the Grecians, cunningly catching at all Opportunities of Gain, make
new Sects and Parties, and by their contrary Opinions wrangling and
quarelling concerning the chiefest Points, lead their Scholars into a Maze;
and being uncertain and doubtful what to pitch upon for certain truth, their
Minds are fluctuating and in suspence all the days of their Lives, and unable
to give a certain assent unto any thing. For if any Man will but examine the
most eminent Sects of the Philosophers, he shall find them much differing
among themselves, and even opposing one another in the most weighty
parts of their Philosophy. But to return to the Chaldeans, they hold that the
World is eternal, which had neither any certain Beginning, nor shall have
any End; but all agree, that all things are order'd, and this beautiful Fabrick
is supported by a Divine Providence, and that the Motions of the Heavens
are not perform'd by chance and of their own accord, but by a certain and
determinate Will and Appointment of the Gods.
"Therefore from a long observation of the Stars, and an exact Knowledge
of the motions and influences of every one of them, wherein they excel all
others, they fortel many things that are to come to pass.
"They say that the Five Stars which some call Planets, but they
Interpreters, are most worthy of Consideration, both for their motions and
their remarkable influences, especially that which the Grecians call Saturn.
The brightest of them all, and which often portends many and great Events,
they call Sol, the other Four they name Mars, Venus, Mercury, and Jupiter,
with our own Country Astrologers. They give the Name of Interpreters to
these Stars, because these only by a peculiar Motion do portend things to
come, and instead of Jupiters, do declare to Men before-hand the good-will
of the Gods; whereas the other Stars (not being of the number of the
Planets) have a constant ordinary motion. Future Events (they say) are
pointed at sometimes by their Rising, and sometimes by their Setting, and at
other times by their Colour, as may be experienc'd by those that will
diligently observe it; sometimes foreshewing Hurricanes, at other times
Tempestuous Rains, and then again exceeding Droughts. By these, they say,
are often portended the appearance of Comets, Eclipses of the Sun and

Moon, Earthquakes and all other the various Changes and remarkable
effects in the Air, boding good and bad, not only to Nations in general, but
to Kings and Private Persons in particular. Under the course of these
Planets, they say are Thirty Stars, which they call Counselling Gods, half of
whom observe what is done under the Earth, and the other half take notice
of the actions of Men upon the Earth, and what is transacted in the Heavens.
Once every Ten Days space (they say) one of the highest Order of these
Stars descends to them that are of the lowest, like a Messenger sent from
them above; and then again another ascends from those below to them
above, and that this is their constant natural motion to continue for ever.
The chief of these Gods, they say, are Twelve in number, to each of which
they attribute a Month, and one Sign of the Twelve in the Zodiack.
"Through these Twelve Signs the Sun, Moon, and the other Five Planets
run their Course. The Sun in a Years time, and the Moon in the space of a
Month. To every one of the Planets they assign their own proper Courses,
which are perform'd variously in lesser or shorter time according as their
several motions are quicker or slower. These Stars, they say, have a great
influence both as to good and bad in Mens Nativities; and from the
consideration of their several Natures, may be foreknown what will befal
Men afterwards. As they foretold things to come to other Kings formerly, so
they did to Alexander who conquer'd Darius, and to his Successors
Antigonus and Seleucus Nicator; and accordingly things fell out as they
declar'd; which we shall relate particularly hereafter in a more convenient
time. They tell likewise private Men their Fortunes so certainly, that those
who have found the thing true by Experience, have esteem'd it a Miracle,
and above the reach of man to perform. Out of the Circle of the Zodiack
they describe Four and Twenty Stars, Twelve towards the North Pole, and
as many to the South.
"Those which we see, they assign to the living; and the other that do not
appear, they conceive are Constellations for the Dead; and they term them
Judges of all things. The Moon, they say, is in the lowest Orb; and being
therefore next to the Earth (because she is so small), she finishes her Course
in a little time, not through the swiftness of her Motion, but the shortness of
her Sphear. In that which they affirm (that she has but a borrow'd light, and
that when she is eclips'd, it's caus'd by the interposition of the shadow of the
Earth) they agree with the Grecians.

"Their Rules and Notions concerning the Eclipses of the Sun are but
weak and mean, which they dare not positively foretel, nor fix a certain
time for them. They have likewise Opinions concerning the Earth peculiar
to themselves, affirming it to resemble a Boat, and to be hollow, to prove
which, and other things relating to the frame of the World, they abound in
Arguments; but to give a particular Account of 'em, we conceive would be a
thing foreign to our History. But this any Man may justly and truly say, That
the Chaldeans far exceed all other Men in the Knowledge of Astrology, and
have study'd it most of any other Art or Science: But the number of years
during which the Chaldeans say, those of their Profession have given
themselves to the study of this natural Philosophy, is incredible; for when
Alexander was in Asia, they reckon'd up Four Hundred and Seventy
Thousand Years since they first began to observe the Motions of the Stars."
Let us now supplement this estimate of Babylonian influence with
another estimate written in our own day, and quoted by one of the most
recent historians of Babylonia and Assyria.(24) The estimate in question is
that of Canon Rawlinson in his Great Oriental Monarchies.(25) Of
Babylonia he says:
"Hers was apparently the genius which excogitated an alphabet; worked
out the simpler problems of arithmetic; invented implements for measuring
the lapse of time; conceived the idea of raising enormous structures with the
poorest of all materials, clay; discovered the art of polishing, boring, and
engraving gems; reproduced with truthfulness the outlines of human and
animal forms; attained to high perfection in textile fabrics; studied with
success the motions of the heavenly bodies; conceived of grammar as a
science; elaborated a system of law; saw the value of an exact chronology
—in almost every branch of science made a beginning, thus rendering it
comparatively easy for other nations to proceed with the superstructure.... It
was from the East, not from Egypt, that Greece derived her architecture, her
sculpture, her science, her philosophy, her mathematical knowledge—in a
word, her intellectual life. And Babylon was the source to which the entire
stream of Eastern civilization may be traced. It is scarcely too much to say
that, but for Babylon, real civilization might not yet have dawned upon the
earth."
Considering that a period of almost two thousand years separates the
times of writing of these two estimates, the estimates themselves are

singularly in unison. They show that the greatest of Oriental nations has not
suffered in reputation at the hands of posterity. It is indeed almost
impossible to contemplate the monuments of Babylonian and Assyrian
civilization that are now preserved in the European and American museums
without becoming enthusiastic. That certainly was a wonderful civilization
which has left us the tablets on which are inscribed the laws of a Khamurabi
on the one hand, and the art treasures of the palace of an Asshurbanipal on
the other. Yet a candid consideration of the scientific attainments of the
Babylonians and Assyrians can scarcely arouse us to a like enthusiasm. In
considering the subject we have seen that, so far as pure science is
concerned, the efforts of the Babylonians and Assyrians chiefly centred
about the subjects of astrology and magic. With the records of their ghost-
haunted science fresh in mind, one might be forgiven for a momentary
desire to take issue with Canon Rawlinson's words. We are assured that the
scientific attainments of Europe are almost solely to be credited to
Babylonia and not to Egypt, but we should not forget that Plato, the greatest
of the Greek thinkers, went to Egypt and not to Babylonia to pursue his
studies when he wished to penetrate the secrets of Oriental science and
philosophy. Clearly, then, classical Greece did not consider Babylonia as
having a monopoly of scientific knowledge, and we of to-day, when we
attempt to weigh the new evidence that has come to us in recent generations
with the Babylonian records themselves, find that some, at least, of the
heritages for which Babylonia has been praised are of more than doubtful
value. Babylonia, for example, gave us our seven-day week and our system
of computing by twelves. But surely the world could have got on as well
without that magic number seven; and after some hundreds of generations
we are coming to feel that the decimal system of the Egyptians has
advantages over the duodecimal system of the Babylonians. Again, the
Babylonians did not invent the alphabet; they did not even accept it when
all the rest of the world had recognized its value. In grammar and
arithmetic, as with astronomy, they seemed not to have advanced greatly, if
at all, upon the Egyptians. One field in which they stand out in startling pre-
eminence is the field of astrology; but this, in the estimate of modern
thought, is the very negation of science. Babylonia impressed her
superstitions on the Western world, and when we consider the baleful
influence of these superstitions, we may almost question whether we might
not reverse Canon Rawlinson's estimate and say that perhaps but for

Babylonia real civilization, based on the application of true science, might
have dawned upon the earth a score of centuries before it did. Yet, after all,
perhaps this estimate is unjust. Society, like an individual organism, must
creep before it can walk, and perhaps the Babylonian experiments in
astrology and magic, which European civilization was destined to copy for
some three or four thousand years, must have been made a part of the
necessary evolution of our race in one place or in another. That thought,
however, need not blind us to the essential fact, which the historian of
science must needs admit, that for the Babylonian, despite his boasted
culture, science spelled superstition.

IV. THE DEVELOPMENT OF THE ALPHABET
Before we turn specifically to the new world of the west, it remains to
take note of what may perhaps be regarded as the very greatest achievement
of ancient science. This was the analysis of speech sounds, and the resulting
development of a system of alphabetical writing. To comprehend the series
of scientific inductions which led to this result, we must go back in
imagination and trace briefly the development of the methods of recording
thought by means of graphic symbols. In other words, we must trace the
evolution of the art of writing. In doing so we cannot hold to national lines
as we have done in the preceding two chapters, though the efforts of the two
great scientific nations just considered will enter prominently into the story.
The familiar Greek legend assures us that a Phoenician named Kadmus
was the first to bring a knowledge of letters into Europe. An elaboration of
the story, current throughout classical times, offered the further explanation
that the Phoenicians had in turn acquired the art of writing from the
Egyptians or Babylonians. Knowledge as to the true origin and
development of the art of writing did not extend in antiquity beyond such
vagaries as these. Nineteenth-century studies gave the first real clews to an
understanding of the subject. These studies tended to authenticate the
essential fact on which the legend of Kadmus was founded; to the extent, at
least, of making it probable that the later Grecian alphabet was introduced
from Phoenicia—though not, of course, by any individual named Kadmus,
the latter being, indeed, a name of purely Greek origin. Further studies of
the past generation tended to corroborate the ancient belief as to the original
source of the Phoenician alphabet, but divided scholars between two
opinions: the one contending that the Egyptian hieroglyphics were the
source upon which the Phoenicians drew; and the other contending with
equal fervor that the Babylonian wedge character must be conceded that
honor.
But, as has often happened in other fields after years of acrimonious
controversy, a new discovery or two may suffice to show that neither
contestant was right. After the Egyptologists of the school of De Rouge(1)
thought they had demonstrated that the familiar symbols of the Phoenician

alphabet had been copied from that modified form of Egyptian
hieroglyphics known as the hieratic writing, the Assyriologists came
forward to prove that certain characters of the Babylonian syllabary also
show a likeness to the alphabetical characters that seemingly could not be
due to chance. And then, when a settlement of the dispute seemed almost
hopeless, it was shown through the Egyptian excavations that characters
even more closely resembling those in dispute had been in use all about the
shores of the Mediterranean, quite independently of either Egyptian or
Assyrian writings, from periods so ancient as to be virtually prehistoric.
Coupled with this disconcerting discovery are the revelations brought to
light by the excavations at the sites of Knossos and other long-buried cities
of the island of Crete.(2) These excavations, which are still in progress,
show that the art of writing was known and practised independently in
Crete before that cataclysmic overthrow of the early Greek civilization
which archaeologists are accustomed to ascribe to the hypothetical invasion
of the Dorians. The significance of this is that the art of writing was known
in Europe long before the advent of the mythical Kadmus. But since the
early Cretan scripts are not to be identified with the scripts used in Greece
in historical times, whereas the latter are undoubtedly of lineal descent from
the Phoenician alphabet, the validity of the Kadmus legend, in a modified
form, must still be admitted.
As has just been suggested, the new knowledge, particularly that which
related to the great antiquity of characters similar to the Phoenician
alphabetical signs, is somewhat disconcerting. Its general trend, however, is
quite in the same direction with most of the new archaeological knowledge
of recent decades—-that is to say, it tends to emphasize the idea that human
civilization in most of its important elaborations is vastly older than has
hitherto been supposed. It may be added, however, that no definite clews
are as yet available that enable us to fix even an approximate date for the
origin of the Phoenician alphabet. The signs, to which reference has been
made, may well have been in existence for thousands of years, utilized
merely as property marks, symbols for counting and the like, before the
idea of setting them aside as phonetic symbols was ever conceived. Nothing
is more certain, in the judgment of the present-day investigator, than that
man learned to write by slow and painful stages. It is probable that the
conception of such an analysis of speech sounds as would make the idea of
an alphabet possible came at a very late stage of social evolution, and as the

culminating achievement of a long series of improvements in the art of
writing. The precise steps that marked this path of intellectual development
can for the most part be known only by inference; yet it is probable that the
main chapters of the story may be reproduced with essential accuracy.
FIRST STEPS
For the very first chapters of the story we must go back in imagination to
the prehistoric period. Even barbaric man feels the need of self-expression,
and strives to make his ideas manifest to other men by pictorial signs. The
cave-dwellers scratched pictures of men and animals on the surface of a
reindeer horn or mammoth tusk as mementos of his prowess. The American
Indian does essentially the same thing to-day, making pictures that crudely
record his successes in war and the chase. The Northern Indian had got no
farther than this when the white man discovered America; but the Aztecs of
the Southwest and the Maya people of Yucatan had carried their picture-
making to a much higher state of elaboration.(3) They had developed
systems of pictographs or hieroglyphics that would doubtless in the course
of generations have been elaborated into alphabetical systems, had not the
Europeans cut off the civilization of which they were the highest exponents.
What the Aztec and Maya were striving towards in the sixteenth century
A.D., various Oriental nations had attained at least five or six thousand
years earlier. In Egypt at the time of the pyramid-builders, and in Babylonia
at the same epoch, the people had developed systems of writing that
enabled them not merely to present a limited range of ideas pictorially, but
to express in full elaboration and with finer shades of meaning all the ideas
that pertain to highly cultured existence. The man of that time made records
of military achievements, recorded the transactions of every-day business
life, and gave expression to his moral and spiritual aspirations in a way
strangely comparable to the manner of our own time. He had perfected
highly elaborate systems of writing.
EGYPTIAN WRITING
Of the two ancient systems of writing just referred to as being in vogue at
the so-called dawnings of history, the more picturesque and suggestive was
the hieroglyphic system of the Egyptians. This is a curiously conglomerate
system of writing, made up in part of symbols reminiscent of the crudest
stages of picture-writing, in part of symbols having the phonetic value of
syllables, and in part of true alphabetical letters. In a word, the Egyptian

writing represents in itself the elements of the various stages through which
the art of writing has developed.(4) We must conceive that new features
were from time to time added to it, while the old features, curiously enough,
were not given up.
Here, for example, in the midst of unintelligible lines and pot-hooks, are
various pictures that are instantly recognizable as representations of hawks,
lions, ibises, and the like. It can hardly be questioned that when these
pictures were first used calligraphically they were meant to represent the
idea of a bird or animal. In other words, the first stage of picture-writing did
not go beyond the mere representation of an eagle by the picture of an
eagle. But this, obviously, would confine the presentation of ideas within
very narrow limits. In due course some inventive genius conceived the
thought of symbolizing a picture. To him the outline of an eagle might
represent not merely an actual bird, but the thought of strength, of courage,
or of swift progress. Such a use of symbols obviously extends the range of
utility of a nascent art of writing. Then in due course some wonderful
psychologist—or perhaps the joint efforts of many generations of
psychologists—made the astounding discovery that the human voice, which
seems to flow on in an unbroken stream of endlessly varied modulations
and intonations, may really be analyzed into a comparatively limited
number of component sounds—into a few hundreds of syllables. That
wonderful idea conceived, it was only a matter of time until it would occur
to some other enterprising genius that by selecting an arbitrary symbol to
represent each one of these elementary sounds it would be possible to make
a written record of the words of human speech which could be reproduced
—rephonated—by some one who had never heard the words and did not
know in advance what this written record contained. This, of course, is what
every child learns to do now in the primer class, but we may feel assured
that such an idea never occurred to any human being until the peculiar
forms of pictographic writing just referred to had been practised for many
centuries. Yet, as we have said, some genius of prehistoric Egypt conceived
the idea and put it into practical execution, and the hieroglyphic writing of
which the Egyptians were in full possession at the very beginning of what
we term the historical period made use of this phonetic system along with
the ideographic system already described.
So fond were the Egyptians of their pictorial symbols used
ideographically that they clung to them persistently throughout the entire

period of Egyptian history. They used symbols as phonetic equivalents very
frequently, but they never learned to depend upon them exclusively. The
scribe always interspersed his phonetic signs with some other signs
intended as graphic aids. After spelling a word out in full, he added a
picture, sometimes even two or three pictures, representative of the
individual thing, or at least of the type of thing to which the word belongs.
Two or three illustrations will make this clear.
Thus qeften, monkey, is spelled out in full, but the picture of a monkey is
added as a determinative; second, qenu, cavalry, after being spelled, is made
unequivocal by the introduction of a picture of a horse; third, temati, wings,
though spelled elaborately, has pictures of wings added; and fourth, tatu,
quadrupeds, after being spelled, has a picture of a quadruped, and then the
picture of a hide, which is the usual determinative of a quadruped, followed
by three dashes to indicate the plural number.
It must not be supposed, however, that it was a mere whim which led the
Egyptians to the use of this system of determinatives. There was sound
reason back of it. It amounted to no more than the expedient we adopt when
we spell "to," "two," or "too," in indication of a single sound with three
different meanings. The Egyptian language abounds in words having more
than one meaning, and in writing these it is obvious that some means of
distinction is desirable. The same thing occurs even more frequently in the
Chinese language, which is monosyllabic. The Chinese adopt a more
clumsy expedient, supplying a different symbol for each of the meanings of
a syllable; so that while the actual word-sounds of their speech are only a
few hundreds in number, the characters of their written language mount
high into the thousands.
BABYLONIAN WRITING
While the civilization of the Nile Valley was developing this
extraordinary system of hieroglyphics, the inhabitants of Babylonia were
practising the art of writing along somewhat different lines. It is certain that
they began with picture-making, and that in due course they advanced to the
development of the syllabary; but, unlike their Egyptian cousins, the men of
Babylonia saw fit to discard the old system when they had perfected a better
one.(5) So at a very early day their writing—as revealed to us now through
the recent excavations—had ceased to have that pictorial aspect which
distinguishes the Egyptian script. What had originally been pictures of

objects—fish, houses, and the like—had come to be represented by mere
aggregations of wedge-shaped marks. As the writing of the Babvlonians
was chiefly inscribed on soft clay, the adaptation of this wedge-shaped
mark in lieu of an ordinary line was probably a mere matter of convenience,
since the sharp-cornered implement used in making the inscription naturally
made a wedge-shaped impression in the clay. That, however, is a detail. The
essential thing is that the Babylonian had so fully analyzed the speech-
sounds that he felt entire confidence in them, and having selected a
sufficient number of conventional characters—each made up of wedge-
shaped lines—to represent all the phonetic sounds of his language, spelled
the words out in syllables and to some extent dispensed with the
determinative signs which, as we have seen, played so prominent a part in
the Egyptian writing. His cousins the Assyrians used habitually a system of
writing the foundation of which was an elaborate phonetic syllabary; a
system, therefore, far removed from the old crude pictograph, and in some
respects much more developed than the complicated Egyptian method; yet,
after all, a system that stopped short of perfection by the wide gap that
separates the syllabary from the true alphabet.
A brief analysis of speech sounds will aid us in understanding the real
nature of the syllabary. Let us take for consideration the consonantal sound
represented by the letter b. A moment's consideration will make it clear that
this sound enters into a large number of syllables. There are, for example, at
least twenty vowel sounds in the English language, not to speak of certain
digraphs; that is to say, each of the important vowels has from two to six
sounds. Each of these vowel sounds may enter into combination with the b
sound alone to form three syllables; as ba, ab, bal, be, eb, bel, etc. Thus
there are at least sixty b-sound syllables. But this is not the end, for other
consonantal sounds may be associated in the syllables in such combinations
as bad, bed, bar, bark, cab, etc. As each of the other twenty odd consonantal
sounds may enter into similar combinations, it is obvious that there are
several hundreds of fundamental syllables to be taken into account in any
syllabic system of writing. For each of these syllables a symbol must be set
aside and held in reserve as the representative of that particular sound. A
perfect syllabary, then, would require some hundred or more of symbols to
represent b sounds alone; and since the sounds for c, d, f, and the rest are
equally varied, the entire syllabary would run into thousands of characters,
almost rivalling in complexity the Chinese system. But in practice the most

perfect syllabary, Such as that of the Babylonians, fell short of this degree
of precision through ignoring the minor shades of sound; just as our own
alphabet is content to represent some thirty vowel sounds by five letters,
ignoring the fact that a, for example, has really half a dozen distinct
phonetic values. By such slurring of sounds the syllabary is reduced far
below its ideal limits; yet even so it retains three or four hundred characters.
In point of fact, such a work as Professor Delitzsch's Assyrian
Grammar(6) presents signs for three hundred and thirty-four syllables,
together with sundry alternative signs and determinatives to tax the memory
of the would-be reader of Assyrian. Let us take for example a few of the b
sounds. It has been explained that the basis of the Assyrian written character
is a simple wedge-shaped or arrow-head mark. Variously repeated and
grouped, these marks make up the syllabic characters.
To learn some four hundred such signs as these was the task set, as an
equivalent of learning the a b c's, to any primer class in old Assyria in the
long generations when that land was the culture Centre of the world. Nor
was the task confined to the natives of Babylonia and Assyria alone. About
the fifteenth century B.C., and probably for a long time before and after that
period, the exceedingly complex syllabary of the Babylonians was the
official means of communication throughout western Asia and between
Asia and Egypt, as we know from the chance discovery of a collection of
letters belonging to the Egyptian king Khun-aten, preserved at Tel-el-
Amarna. In the time of Ramses the Great the Babylonian writing was in all
probability considered by a majority of the most highly civilized people in
the world to be the most perfect script practicable. Doubtless the average
scribe of the time did not in the least realize the waste of energy involved in
his labors, or ever suspect that there could be any better way of writing.
Yet the analysis of any one of these hundreds of syllables into its
component phonetic elements—had any one been genius enough to make
such analysis—would have given the key to simpler and better things. But
such an analysis was very hard to make, as the sequel shows. Nor is the
utility of such an analysis self-evident, as the experience of the Egyptians
proved. The vowel sound is so intimately linked with the consonant—the
con-sonant, implying this intimate relation in its very name—that it seemed
extremely difficult to give it individual recognition. To set off the mere
labial beginning of the sound by itself, and to recognize it as an all-essential

element of phonation, was the feat at which human intelligence so long
balked. The germ of great things lay in that analysis. It was a process of
simplification, and all art development is from the complex to the simple.
Unfortunately, however, it did not seem a simplification, but rather quite the
reverse. We may well suppose that the idea of wresting from the syllabary
its secret of consonants and vowels, and giving to each consonantal sound a
distinct sign, seemed a most cumbersome and embarrassing complication to
the ancient scholars—that is to say, after the time arrived when any one
gave such an idea expression. We can imagine them saying: "You will
oblige us to use four signs instead of one to write such an elementary
syllable as 'bard,' for example. Out upon such endless perplexity!" Nor is
such a suggestion purely gratuitous, for it is an historical fact that the old
syllabary continued to be used in Babylon hundreds of years after the
alphabetical system had been introduced.(7) Custom is everything in
establishing our prejudices. The Japanese to-day rebel against the
introduction of an alphabet, thinking it ambiguous.
Yet, in the end, conservatism always yields, and so it was with opposition
to the alphabet. Once the idea of the consonant had been firmly grasped, the
old syllabary was doomed, though generations of time might be required to
complete the obsequies—generations of time and the influence of a new
nation. We have now to inquire how and by whom this advance was made.
THE ALPHABET ACHIEVED
We cannot believe that any nation could have vaulted to the final stage of
the simple alphabetical writing without tracing the devious and difficult
way of the pictograph and the syllabary. It is possible, however, for a
cultivated nation to build upon the shoulders of its neighbors, and, profiting
by the experience of others, to make sudden leaps upward and onward. And
this is seemingly what happened in the final development of the art of
writing. For while the Babylonians and Assyrians rested content with their
elaborate syllabary, a nation on either side of them, geographically
speaking, solved the problem, which they perhaps did not even recognize as
a problem; wrested from their syllabary its secret of consonants and vowels,
and by adopting an arbitrary sign for each consonantal sound, produced that
most wonderful of human inventions, the alphabet.
The two nations credited with this wonderful achievement are the
Phoenicians and the Persians. But it is not usually conceded that the two are

entitled to anything like equal credit. The Persians, probably in the time of
Cyrus the Great, used certain characters of the Babylonian script for the
construction of an alphabet; but at this time the Phoenician alphabet had
undoubtedly been in use for some centuries, and it is more than probable
that the Persian borrowed his idea of an alphabet from a Phoenician source.
And that, of course, makes all the difference. Granted the idea of an
alphabet, it requires no great reach of constructive genius to supply a set of
alphabetical characters; though even here, it may be added parenthetically, a
study of the development of alphabets will show that mankind has all along
had a characteristic propensity to copy rather than to invent.
Regarding the Persian alphabet-maker, then, as a copyist rather than a
true inventor, it remains to turn attention to the Phoenician source whence,
as is commonly believed, the original alphabet which became "the mother
of all existing alphabets" came into being. It must be admitted at the outset
that evidence for the Phoenician origin of this alphabet is traditional rather
than demonstrative. The Phoenicians were the great traders of antiquity;
undoubtedly they were largely responsible for the transmission of the
alphabet from one part of the world to another, once it had been invented.
Too much credit cannot be given them for this; and as the world always
honors him who makes an idea fertile rather than the originator of the idea,
there can be little injustice in continuing to speak of the Phoenicians as the
inventors of the alphabet. But the actual facts of the case will probably
never be known. For aught we know, it may have been some dreamy-eyed
Israelite, some Babylonian philosopher, some Egyptian mystic, perhaps
even some obscure Cretan, who gave to the hard-headed Phoenician trader
this conception of a dismembered syllable with its all-essential, elemental,
wonder-working consonant. But it is futile now to attempt even to surmise
on such unfathomable details as these. Suffice it that the analysis was made;
that one sign and no more was adopted for each consonantal sound of the
Semitic tongue, and that the entire cumbersome mechanism of the Egyptian
and Babylonian writing systems was rendered obsolescent. These systems
did not yield at once, to be sure; all human experience would have been set
at naught had they done so. They held their own, and much more than held
their own, for many centuries. After the Phoenicians as a nation had ceased
to have importance; after their original script had been endlessly modified
by many alien nations; after the original alphabet had made the conquest of
all civilized Europe and of far outlying portions of the Orient—the Egyptian

and Babylonian scribes continued to indite their missives in the same old
pictographs and syllables.
The inventive thinker must have been struck with amazement when, after
making the fullest analysis of speech-sounds of which he was capable, he
found himself supplied with only a score or so of symbols. Yet as regards
the consonantal sounds he had exhausted the resources of the Semitic
tongue. As to vowels, he scarcely considered them at all. It seemed to him
sufficient to use one symbol for each consonantal sound. This reduced the
hitherto complex mechanism of writing to so simple a system that the
inventor must have regarded it with sheer delight. On the other hand, the
conservative scholar doubtless thought it distinctly ambiguous. In truth, it
must be admitted that the system was imperfect. It was a vast improvement
on the old syllabary, but it had its drawbacks. Perhaps it had been made a
bit too simple; certainly it should have had symbols for the vowel sounds as
well as for the consonants. Nevertheless, the vowel-lacking alphabet seems
to have taken the popular fancy, and to this day Semitic people have never
supplied its deficiencies save with certain dots and points.
Peoples using the Aryan speech soon saw the defect, and the Greeks
supplied symbols for several new sounds at a very early day.(8) But there
the matter rested, and the alphabet has remained imperfect. For the purposes
of the English language there should certainly have been added a dozen or
more new characters. It is clear, for example, that, in the interest of
explicitness, we should have a separate symbol for the vowel sound in each
of the following syllables: bar, bay, bann, ball, to cite a single illustration.
There is, to be sure, a seemingly valid reason for not extending our
alphabet, in the fact that in multiplying syllables it would be difficult to
select characters at once easy to make and unambiguous. Moreover, the
conservatives might point out, with telling effect, that the present alphabet
has proved admirably effective for about three thousand years. Yet the fact
that our dictionaries supply diacritical marks for some thirty vowels sounds
to indicate the pronunciation of the words of our every-day speech, shows
how we let memory and guessing do the work that might reasonably be
demanded of a really complete alphabet. But, whatever its defects, the
existing alphabet is a marvellous piece of mechanism, the result of
thousands of years of intellectual effort. It is, perhaps without exception, the
most stupendous invention of the human intellect within historical times—

an achievement taking rank with such great prehistoric discoveries as the
use of articulate speech, the making of a fire, and the invention of stone
implements, of the wheel and axle, and of picture-writing. It made possible
for the first time that education of the masses upon which all later progress
of civilization was so largely to depend.

V. THE BEGINNINGS OF GREEK SCIENCE
Herodotus, the Father of History, tells us that once upon a time—which
time, as the modern computator shows us, was about the year 590 B.C.—a
war had risen between the Lydians and the Medes and continued five years.
"In these years the Medes often discomfited the Lydians and the Lydians
often discomfited the Medes (and among other things they fought a battle
by night); and yet they still carried on the war with equally balanced
fortitude. In the sixth year a battle took place in which it happened, when
the fight had begun, that suddenly the day became night. And this change of
the day Thales, the Milesian, had foretold to the Ionians, laying down as a
limit this very year in which the change took place. The Lydians, however,
and the Medes, when they saw that it had become night instead of day,
ceased from their fighting and were much more eager, both of them, that
peace should be made between them."
This memorable incident occurred while Alyattus, father of Croesus, was
king of the Lydians. The modern astronomer, reckoning backward,
estimates this eclipse as occurring probably May 25th, 585 B.C. The date is
important as fixing a mile-stone in the chronology of ancient history, but it
is doubly memorable because it is the first recorded instance of a predicted
eclipse. Herodotus, who tells the story, was not born until about one
hundred years after the incident occurred, but time had not dimmed the
fame of the man who had performed the necromantic feat of prophecy.
Thales, the Milesian, thanks in part at least to this accomplishment, had
been known in life as first on the list of the Seven Wise Men of Greece, and
had passed into history as the father of Greek philosophy. We may add that
he had even found wider popular fame through being named by Hippolytus,
and then by Father aesop, as the philosopher who, intent on studying the
heavens, fell into a well; "whereupon," says Hippolytus, "a maid-servant
named Thratta laughed at him and said, 'In his search for things in the sky
he does not see what is at his feet.'"
Such citations as these serve to bring vividly to mind the fact that we are
entering a new epoch of thought. Hitherto our studies have been
impersonal. Among Egyptians and Babylonians alike we have had to deal

with classes of scientific records, but we have scarcely come across a single
name. Now, however, we shall begin to find records of the work of
individual investigators. In general, from now on, we shall be able to trace
each great idea, if not to its originator, at least to some one man of genius
who was prominent in bringing it before the world. The first of these
vitalizers of thought, who stands out at the beginnings of Greek history, is
this same Thales, of Miletus. His is not a very sharply defined personality
as we look back upon it, and we can by no means be certain that all the
discoveries which are ascribed to him are specifically his. Of his
individuality as a man we know very little. It is not even quite certain as to
where he was born; Miletus is usually accepted as his birthplace, but one
tradition makes him by birth a Phenician. It is not at all in question,
however, that by blood he was at least in part an Ionian Greek. It will be
recalled that in the seventh century B.C., when Thales was born—and for a
long time thereafter—the eastern shores of the aegean Sea were quite as
prominently the centre of Greek influence as was the peninsula of Greece
itself. Not merely Thales, but his followers and disciples, Anaximander and
Anaximenes, were born there. So also was Herodotas, the Father of History,
not to extend the list. There is nothing anomalous, then, in the fact that
Thales, the father of Greek thought, was born and passed his life on soil that
was not geographically a part of Greece; but the fact has an important
significance of another kind. Thanks to his environment, Thales was
necessarily brought more or less in contact with Oriental ideas. There was
close commercial contact between the land of his nativity and the great
Babylonian capital off to the east, as also with Egypt. Doubtless this
association was of influence in shaping the development of Thales's mind.
Indeed, it was an accepted tradition throughout classical times that the
Milesian philosopher had travelled in Egypt, and had there gained at least
the rudiments of his knowledge of geometry. In the fullest sense, then,
Thales may be regarded as representing a link in the chain of thought
connecting the learning of the old Orient with the nascent scholarship of the
new Occident. Occupying this position, it is fitting that the personality of
Thales should partake somewhat of mystery; that the scene may not be
shifted too suddenly from the vague, impersonal East to the individualism
of Europe.
All of this, however, must not be taken as casting any doubt upon the
existence of Thales as a real person. Even the dates of his life—640 to 546

B.C.—may be accepted as at least approximately trustworthy; and the
specific discoveries ascribed to him illustrate equally well the stage of
development of Greek thought, whether Thales himself or one of his
immediate disciples were the discoverer. We have already mentioned the
feat which was said to have given Thales his great reputation. That Thales
was universally credited with having predicted the famous eclipse is beyond
question. That he actually did predict it in any precise sense of the word is
open to doubt. At all events, his prediction was not based upon any such
precise knowledge as that of the modern astronomer. There is, indeed, only
one way in which he could have foretold the eclipse, and that is through
knowledge of the regular succession of preceding eclipses. But that
knowledge implies access on the part of some one to long series of records
of practical observations of the heavens. Such records, as we have seen,
existed in Egypt and even more notably in Babylonia. That these records
were the source of the information which established the reputation of
Thales is an unavoidable inference. In other words, the magical prevision of
the father of Greek thought was but a reflex of Oriental wisdom.
Nevertheless, it sufficed to establish Thales as the father of Greek
astronomy. In point of fact, his actual astronomical attainments would
appear to have been meagre enough. There is nothing to show that he
gained an inkling of the true character of the solar system. He did not even
recognize the sphericity of the earth, but held, still following the Oriental
authorities, that the world is a flat disk. Even his famous cosmogonic guess,
according to which water is the essence of all things and the primordial
element out of which the earth was developed, is but an elaboration of the
Babylonian conception.
When we turn to the other field of thought with which the name of Thales
is associated—namely, geometry—we again find evidence of the Oriental
influence. The science of geometry, Herodotus assures us, was invented in
Egypt. It was there an eminently practical science, being applied, as the
name literally suggests, to the measurement of the earth's surface.
Herodotus tells us that the Egyptians were obliged to cultivate the science
because the periodical inundations washed away the boundary-lines
between their farms. The primitive geometer, then, was a surveyor. The
Egyptian records, as now revealed to us, show that the science had not been
carried far in the land of its birth. The Egyptian geometer was able to
measure irregular pieces of land only approximately. He never fully grasped

the idea of the perpendicular as the true index of measurement for the
triangle, but based his calculations upon measurements of the actual side of
that figure. Nevertheless, he had learned to square the circle with a close
approximation to the truth, and, in general, his measurement sufficed for all
his practical needs. Just how much of the geometrical knowledge which
added to the fame of Thales was borrowed directly from the Egyptians, and
how much he actually created we cannot be sure. Nor is the question raised
in disparagement of his genius. Receptivity is the first prerequisite to
progressive thinking, and that Thales reached out after and imbibed portions
of Oriental wisdom argues in itself for the creative character of his genius.
Whether borrower of originator, however, Thales is credited with the
expression of the following geometrical truths:
1. That the circle is bisected by its diameter.
2. That the angles at the base of an isosceles triangle are equal.
3. That when two straight lines cut each other the vertical opposite angles
are equal.
4. That the angle in a semicircle is a right angle.
5. That one side and one acute angle of a right-angle triangle determine
the other sides of the triangle.
It was by the application of the last of these principles that Thales is said
to have performed the really notable feat of measuring the distance of a ship
from the shore, his method being precisely the same in principle as that by
which the guns are sighted on a modern man-of-war. Another practical
demonstration which Thales was credited with making, and to which also
his geometrical studies led him, was the measurement of any tall object,
such as a pyramid or building or tree, by means of its shadow. The method,
though simple enough, was ingenious. It consisted merely in observing the
moment of the day when a perpendicular stick casts a shadow equal to its
own length. Obviously the tree or monument would also cast a shadow
equal to its own height at the same moment. It remains then but to measure
the length of this shadow to determine the height of the object. Such feats as
this evidence the practicality of the genius of Thales. They suggest that
Greek science, guided by imagination, was starting on the high-road of
observation. We are told that Thales conceived for the first time the
geometry of lines, and that this, indeed, constituted his real advance upon
the Egyptians. We are told also that he conceived the eclipse of the sun as a

purely natural phenomenon, and that herein lay his advance upon the
Chaldean point of view. But if this be true Thales was greatly in advance of
his time, for it will be recalled that fully two hundred years later the Greeks
under Nicias before Syracuse were so disconcerted by the appearance of an
eclipse, which was interpreted as a direct omen and warning, that Nicias
threw away the last opportunity to rescue his army. Thucydides, it is true, in
recording this fact speaks disparagingly of the superstitious bent of the
mind of Nicias, but Thucydides also was a man far in advance of his time.
All that we know of the psychology of Thales is summed up in the
famous maxim, "Know thyself," a maxim which, taken in connection with
the proven receptivity of the philosopher's mind, suggests to us a
marvellously rounded personality.
The disciples or successors of Thales, Anaximander and Anaximenes,
were credited with advancing knowledge through the invention or
introduction of the sundial. We may be sure, however, that the gnomon,
which is the rudimentary sundial, had been known and used from remote
periods in the Orient, and the most that is probable is that Anaximander
may have elaborated some special design, possibly the bowl-shaped
sundial, through which the shadow of the gnomon would indicate the time.
The same philosopher is said to have made the first sketch of a geographical
map, but this again is a statement which modern researches have shown to
be fallacious, since a Babylonian attempt at depicting the geography of the
world is still preserved to us on a clay tablet. Anaximander may, however,
have been the first Greek to make an attempt of this kind. Here again the
influence of Babylonian science upon the germinating Western thought is
suggested.
It is said that Anaximander departed from Thales's conception of the
earth, and, it may be added, from the Babylonian conception also, in that he
conceived it as a cylinder, or rather as a truncated cone, the upper end of
which is the habitable portion. This conception is perhaps the first of these
guesses through which the Greek mind attempted to explain the apparent
fixity of the earth. To ask what supports the earth in space is most natural,
but the answer given by Anaximander, like that more familiar Greek
solution which transformed the cone, or cylinder, into the giant Atlas, is but
another illustration of that substitution of unwarranted inference for

scientific induction which we have already so often pointed out as
characteristic of the primitive stages of thought.
Anaximander held at least one theory which, as vouched for by various
copyists and commentators, entitles him to be considered perhaps the first
teacher of the idea of organic evolution. According to this idea, man
developed from a fishlike ancestor, "growing up as sharks do until able to
help himself and then coming forth on dry land."(1) The thought here
expressed finds its germ, perhaps, in the Babylonian conception that
everything came forth from a chaos of waters. Yet the fact that the thought
of Anaximander has come down to posterity through such various channels
suggests that the Greek thinker had got far enough away from the Oriental
conception to make his view seem to his contemporaries a novel and
individual one. Indeed, nothing we know of the Oriental line of thought
conveys any suggestion of the idea of transformation of species, whereas
that idea is distinctly formulated in the traditional views of Anaximander.

VI. THE EARLY GREEK PHILOSOPHERS IN
ITALY
Diogenes Laertius tells a story about a youth who, clad in a purple toga,
entered the arena at the Olympian games and asked to compete with the
other youths in boxing. He was derisively denied admission, presumably
because he was beyond the legitimate age for juvenile contestants. Nothing
daunted, the youth entered the lists of men, and turned the laugh on his
critics by coming off victor. The youth who performed this feat was named
Pythagoras. He was the same man, if we may credit the story, who
afterwards migrated to Italy and became the founder of the famous
Crotonian School of Philosophy; the man who developed the religion of the
Orphic mysteries; who conceived the idea of the music of the spheres; who
promulgated the doctrine of metempsychosis; who first, perhaps, of all men
clearly conceived the notion that this world on which we live is a ball which
moves in space and which may be habitable on every side.
A strange development that for a stripling pugilist. But we must not
forget that in the Greek world athletics held a peculiar place. The chief
winner of Olympian games gave his name to an epoch (the ensuing
Olympiad of four years), and was honored almost before all others in the
land. A sound mind in a sound body was the motto of the day. To excel in
feats of strength and dexterity was an accomplishment that even a
philosopher need not scorn. It will be recalled that aeschylus distinguished
himself at the battle of Marathon; that Thucydides, the greatest of Greek
historians, was a general in the Peloponnesian War; that Xenophon, the
pupil and biographer of Socrates, was chiefly famed for having led the Ten
Thousand in the memorable campaign of Cyrus the Younger; that Plato
himself was credited with having shown great aptitude in early life as a
wrestler. If, then, Pythagoras the philosopher was really the Pythagoras who
won the boxing contest, we may suppose that in looking back upon this
athletic feat from the heights of his priesthood—for he came to be almost
deified—he regarded it not as an indiscretion of his youth, but as one of the
greatest achievements of his life. Not unlikely he recalled with pride that he
was credited with being no less an innovator in athletics than in philosophy.

At all events, tradition credits him with the invention of "scientific" boxing.
Was it he, perhaps, who taught the Greeks to strike a rising and swinging
blow from the hip, as depicted in the famous metopes of the Parthenon? If
so, the innovation of Pythagoras was as little heeded in this regard in a
subsequent age as was his theory of the motion of the earth; for to strike a
swinging blow from the hip, rather than from the shoulder, is a trick which
the pugilist learned anew in our own day.
But enough of pugilism and of what, at best, is a doubtful tradition. Our
concern is with another "science" than that of the arena. We must follow the
purple-robed victor to Italy—if, indeed, we be not over-credulous in
accepting the tradition—and learn of triumphs of a different kind that have
placed the name of Pythagoras high on the list of the fathers of Grecian
thought. To Italy? Yes, to the western limits of the Greek world. Here it
was, beyond the confines of actual Greek territory, that Hellenic thought
found its second home, its first home being, as we have seen, in Asia Minor.
Pythagoras, indeed, to whom we have just been introduced, was born on the
island of Samos, which lies near the coast of Asia Minor, but he probably
migrated at an early day to Crotona, in Italy. There he lived, taught, and
developed his philosophy until rather late in life, when, having incurred the
displeasure of his fellow-citizens, he suffered the not unusual penalty of
banishment.
Of the three other great Italic leaders of thought of the early period,
Xenophanes came rather late in life to Elea and founded the famous Eleatic
School, of which Parmenides became the most distinguished ornament.
These two were Ionians, and they lived in the sixth century before our era.
Empedocles, the Sicilian, was of Doric origin. He lived about the middle of
the fifth century B.C., at a time, therefore, when Athens had attained a
position of chief glory among the Greek states; but there is no evidence that
Empedocles ever visited that city, though it was rumored that he returned to
the Peloponnesus to die. The other great Italic philosophers just named,
living, as we have seen, in the previous century, can scarcely have thought
of Athens as a centre of Greek thought. Indeed, the very fact that these men
lived in Italy made that peninsula, rather than the mother-land of Greece,
the centre of Hellenic influence. But all these men, it must constantly be
borne in mind, were Greeks by birth and language, fully recognized as such
in their own time and by posterity. Yet the fact that they lived in a land
which was at no time a part of the geographical territory of Greece must not

be forgotten. They, or their ancestors of recent generations, had been
pioneers among those venturesome colonists who reached out into distant
portions of the world, and made homes for themselves in much the same
spirit in which colonists from Europe began to populate America some two
thousand years later. In general, colonists from the different parts of Greece
localized themselves somewhat definitely in their new homes; yet there
must naturally have been a good deal of commingling among the various
families of pioneers, and, to a certain extent, a mingling also with the earlier
inhabitants of the country. This racial mingling, combined with the well-
known vitalizing influence of the pioneer life, led, we may suppose, to a
more rapid and more varied development than occurred among the home-
staying Greeks. In proof of this, witness the remarkable schools of
philosophy which, as we have seen, were thus developed at the confines of
the Greek world, and which were presently to invade and, as it were, take
by storm the mother-country itself.
As to the personality of these pioneer philosophers of the West, our
knowledge is for the most part more or less traditional. What has been said
of Thales may be repeated, in the main, regarding Pythagoras, Parmenides,
and Empedocles. That they were real persons is not at all in question, but
much that is merely traditional has come to be associated with their names.
Pythagoras was the senior, and doubtless his ideas may have influenced the
others more or less, though each is usually spoken of as the founder of an
independent school. Much confusion has all along existed, however, as to
the precise ideas which were to be ascribed to each of the leaders.
Numberless commentators, indeed, have endeavored to pick out from
among the traditions of antiquity, aided by such fragments, of the writing of
the philosophers as have come down to us, the particular ideas that
characterized each thinker, and to weave these ideas into systems. But such
efforts, notwithstanding the mental energy that has been expended upon
them, were, of necessity, futile, since, in the first place, the ancient
philosophers themselves did not specialize and systematize their ideas
according to modern notions, and, in the second place, the records of their
individual teachings have been too scantily preserved to serve for the
purpose of classification. It is freely admitted that fable has woven an
impenetrable mesh of contradictions about the personalities of these ancient
thinkers, and it would be folly to hope that this same artificer had been less
busy with their beliefs and theories. When one reads that Pythagoras

advocated an exclusively vegetable diet, yet that he was the first to train
athletes on meat diet; that he sacrificed only inanimate things, yet that he
offered up a hundred oxen in honor of his great discovery regarding the
sides of a triangle, and such like inconsistencies in the same biography, one
gains a realizing sense of the extent to which diverse traditions enter into
the story as it has come down to us. And yet we must reflect that most men
change their opinions in the course of a long lifetime, and that the
antagonistic reports may both be true.
True or false, these fables have an abiding interest, since they prove the
unique and extraordinary character of the personality about which they are
woven. The alleged witticisms of a Whistler, in our own day, were
doubtless, for the most part, quite unknown to Whistler himself, yet they
never would have been ascribed to him were they not akin to witticisms that
he did originate—were they not, in short, typical expressions of his
personality. And so of the heroes of the past. "It is no ordinary man," said
George Henry Lewes, speaking of Pythagoras, "whom fable exalts into the
poetic region. Whenever you find romantic or miraculous deeds attributed,
be certain that the hero was great enough to maintain the weight of the
crown of this fabulous glory."(1) We may not doubt, then, that Pythagoras,
Parmenides, and Empedocles, with whose names fable was so busy
throughout antiquity, were men of extraordinary personality. We are here
chiefly concerned, however, neither with the personality of the man nor yet
with the precise doctrines which each one of them taught. A knowledge of
the latter would be interesting were it attainable, but in the confused state of
the reports that have come down to us we cannot hope to be able to ascribe
each idea with precision to its proper source. At best we can merely outline,
even here not too precisely, the scientific doctrines which the Italic
philosophers as a whole seem to have advocated.
First and foremost, there is the doctrine that the earth is a sphere.
Pythagoras is said to have been the first advocate of this theory; but,
unfortunately, it is reported also that Parmenides was its author. This
rivalship for the discovery of an important truth we shall see repeated over
and over in more recent times. Could we know the whole truth, it would
perhaps appear that the idea of the sphericity of the earth was originated
long before the time of the Greek philosophers. But it must be admitted that
there is no record of any sort to give tangible support to such an
assumption. So far as we can ascertain, no Egyptian or Babylonian

astronomer ever grasped the wonderful conception that the earth is round.
That the Italic Greeks should have conceived that idea was perhaps not so
much because they were astronomers as because they were practical
geographers and geometers. Pythagoras, as we have noted, was born at
Samos, and, therefore, made a relatively long sea voyage in passing to Italy.
Now, as every one knows, the most simple and tangible demonstration of
the convexity of the earth's surface is furnished by observation of an
approaching ship at sea. On a clear day a keen eye may discern the mast
and sails rising gradually above the horizon, to be followed in due course
by the hull. Similarly, on approaching the shore, high objects become
visible before those that lie nearer the water. It is at least a plausible
supposition that Pythagoras may have made such observations as these
during the voyage in question, and that therein may lie the germ of that
wonderful conception of the world as a sphere.
To what extent further proof, based on the fact that the earth's shadow
when the moon is eclipsed is always convex, may have been known to
Pythagoras we cannot say. There is no proof that any of the Italic
philosophers made extensive records of astronomical observations as did
the Egyptians and Babylonians; but we must constantly recall that the
writings of classical antiquity have been almost altogether destroyed. The
absence of astronomical records is, therefore, no proof that such records
never existed. Pythagoras, it should be said, is reported to have travelled in
Egypt, and he must there have gained an inkling of astronomical methods.
Indeed, he speaks of himself specifically, in a letter quoted by Diogenes, as
one who is accustomed to study astronomy. Yet a later sentence of the letter,
which asserts that the philosopher is not always occupied about
speculations of his own fancy, suggesting, as it does, the dreamer rather
than the observer, gives us probably a truer glimpse into the philosopher's
mind. There is, indeed, reason to suppose that the doctrine of the sphericity
of the earth appealed to Pythagoras chiefly because it accorded with his
conception that the sphere is the most perfect solid, just as the circle is the
most perfect plane surface. Be that as it may, the fact remains that we have
here, as far as we can trace its origin, the first expression of the scientific
theory that the earth is round. Had the Italic philosophers accomplished
nothing more than this, their accomplishment would none the less mark an
epoch in the progress of thought.

That Pythagoras was an observer of the heavens is further evidenced by
the statement made by Diogenes, on the authority of Parmenides, that
Pythagoras was the first person who discovered or asserted the identity of
Hesperus and Lucifer—that is to say, of the morning and the evening star.
This was really a remarkable discovery, and one that was no doubt
instrumental later on in determining that theory of the mechanics of the
heavens which we shall see elaborated presently. To have made such a
discovery argues again for the practicality of the mind of Pythagoras. His,
indeed, would seem to have been a mind in which practical common-sense
was strangely blended with the capacity for wide and imaginative
generalization. As further evidence of his practicality, it is asserted that he
was the first person who introduced measures and weights among the
Greeks, this assertion being made on the authority of Aristoxenus. It will be
observed that he is said to have introduced, not to have invented, weights
and measures, a statement which suggests a knowledge on the part of the
Greeks that weights and measures were previously employed in Egypt and
Babylonia.
The mind that could conceive the world as a sphere and that interested
itself in weights and measures was, obviously, a mind of the visualizing
type. It is characteristic of this type of mind to be interested in the
tangibilities of geometry, hence it is not surprising to be told that
Pythagoras "carried that science to perfection." The most famous discovery
of Pythagoras in this field was that the square of the hypotenuse of a right-
angled triangle is equal to the squares of the other sides of the triangle. We
have already noted the fable that his enthusiasm over this discovery led him
to sacrifice a hecatomb. Doubtless the story is apocryphal, but doubtless,
also, it expresses the truth as to the fervid joy with which the philosopher
must have contemplated the results of his creative imagination.
No line alleged to have been written by Pythagoras has come down to us.
We are told that he refrained from publishing his doctrines, except by word
of mouth. "The Lucanians and the Peucetians, and the Messapians and the
Romans," we are assured, "flocked around him, coming with eagerness to
hear his discourses; no fewer than six hundred came to him every night; and
if any one of them had ever been permitted to see the master, they wrote of
it to their friends as if they had gained some great advantage." Nevertheless,
we are assured that until the time of Philolaus no doctrines of Pythagoras
were ever published, to which statement it is added that "when the three

celebrated books were published, Plato wrote to have them purchased for
him for a hundred minas."(2) But if such books existed, they are lost to the
modern world, and we are obliged to accept the assertions of relatively late
writers as to the theories of the great Crotonian.
Perhaps we cannot do better than quote at length from an important
summary of the remaining doctrines of Pythagoras, which Diogenes himself
quoted from the work of a predecessor.(3) Despite its somewhat inchoate
character, this summary is a most remarkable one, as a brief analysis of its
contents will show. It should be explained that Alexander (whose work is
now lost) is said to have found these dogmas set down in the commentaries
of Pythagoras. If this assertion be accepted, we are brought one step nearer
the philosopher himself. The summary is as follows:
"That the monad was the beginning of everything. From the monad
proceeds an indefinite duad, which is subordinate to the monad as to its
cause. That from the monad and the indefinite duad proceed numbers. And
from numbers signs. And from these last, lines of which plane figures
consist. And from plane figures are derived solid bodies. And from solid
bodies sensible bodies, of which last there are four elements—fire, water,
earth, and air. And that the world, which is indued with life and intellect,
and which is of a spherical figure, having the earth, which is also spherical,
and inhabited all over in its centre,(4) results from a combination of these
elements, and derives its motion from them; and also that there are
antipodes, and that what is below, as respects us, is above in respect of
them.
"He also taught that light and darkness, and cold and heat, and dryness
and moisture, were equally divided in the world; and that while heat was
predominant it was summer; while cold had the mastery, it was winter;
when dryness prevailed, it was spring; and when moisture preponderated,
winter. And while all these qualities were on a level, then was the loveliest
season of the year; of which the flourishing spring was the wholesome
period, and the season of autumn the most pernicious one. Of the day, he
said that the flourishing period was the morning, and the fading one the
evening; on which account that also was the least healthy time.
"Another of his theories was that the air around the earth was immovable
and pregnant with disease, and that everything in it was mortal; but that the
upper air was in perpetual motion, and pure and salubrious, and that

everything in that was immortal, and on that account divine. And that the
sun and the moon and the stars were all gods; for in them the warm
principle predominates which is the cause of life. And that the moon derives
its light from the sun. And that there is a relationship between men and the
gods, because men partake of the divine principle; on which account, also,
God exercises his providence for our advantage. Also, that Fate is the cause
of the arrangement of the world both generally and particularly. Moreover,
that a ray from the sun penetrated both the cold aether and the dense aether;
and they call the air the cold aether, and the sea and moisture they call the
dense aether. And this ray descends into the depths, and in this way vivifies
everything. And everything which partakes of the principle of heat lives, on
which account, also, plants are animated beings; but that all living things
have not necessarily souls. And that the soul is a something tom off from
the aether, both warm and cold, from its partaking of the cold aether. And
that the soul is something different from life. Also, that it is immortal,
because that from which it has been detached is immortal.
"Also, that animals are born from one another by seeds, and that it is
impossible for there to be any spontaneous production by the earth. And
that seed is a drop from the brain which contains in itself a warm vapor; and
that when this is applied to the womb it transmits virtue and moisture and
blood from the brain, from which flesh and sinews and bones and hair and
the whole body are produced. And from the vapor is produced the soul, and
also sensation. And that the infant first becomes a solid body at the end of
forty days; but, according to the principles of harmony, it is not perfect till
seven, or perhaps nine, or at most ten months, and then it is brought forth.
And that it contains in itself all the principles of life, which are all
connected together, and by their union and combination form a harmonious
whole, each of them developing itself at the appointed time.
"The senses in general, and especially the sight, are a vapor of excessive
warmth, and on this account a man is said to see through air and through
water. For the hot principle is opposed by the cold one; since, if the vapor in
the eyes were cold, it would have the same temperature as the air, and so
would be dissipated. As it is, in some passages he calls the eyes the gates of
the sun; and he speaks in a similar manner of hearing and of the other
senses.

"He also says that the soul of man is divided into three parts: into
intuition and reason and mind, and that the first and last divisions are found
also in other animals, but that the middle one, reason, is only found in man.
And that the chief abode of the soul is in those parts of the body which are
between the heart and the brain. And that that portion of it which is in the
heart is the mind; but that deliberation and reason reside in the brain.
"Moreover, that the senses are drops from them; and that the reasoning
sense is immortal, but the others are mortal. And that the soul is nourished
by the blood; and that reasons are the winds of the soul. That it is invisible,
and so are its reasons, since the aether itself is invisible. That the links of
the soul are the veins and the arteries and the nerves. But that when it is
vigorous, and is by itself in a quiescent state, then its links are words and
actions. That when it is cast forth upon the earth it wanders about,
resembling the body. Moreover, that Mercury is the steward of the souls,
and that on this account he has the name of Conductor, and Commercial,
and Infernal, since it is he who conducts the souls from their bodies, and
from earth and sea; and that he conducts the pure souls to the highest
region, and that he does not allow the impure ones to approach them, nor to
come near one another, but commits them to be bound in indissoluble
fetters by the Furies. The Pythagoreans also assert that the whole air is full
of souls, and that these are those which are accounted daemons and heroes.
Also, that it is by them that dreams are sent among men, and also the tokens
of disease and health; these last, too, being sent not only to men, but to
sheep also, and other cattle. Also that it is they who are concerned with
purifications and expiations and all kinds of divination and oracular
predictions, and things of that kind."(5)
A brief consideration of this summary of the doctrines of Pythagoras will
show that it at least outlines a most extraordinary variety of scientific ideas.
(1) There is suggested a theory of monads and the conception of the
development from simple to more complex bodies, passing through the
stages of lines, plain figures, and solids to sensible bodies. (2) The doctrine
of the four elements—fire, water, earth, and air—as the basis of all
organisms is put forward. (3) The idea, not merely of the sphericity of the
earth, but an explicit conception of the antipodes, is expressed. (4) A
conception of the sanitary influence of the air is clearly expressed. (5) An
idea of the problems of generation and heredity is shown, together with a
distinct disavowal of the doctrine of spontaneous generation—a doctrine

which, it may be added, remained in vogue, nevertheless, for some twenty-
four hundred years after the time of Pythagoras. (6) A remarkable analysis
of mind is made, and a distinction between animal minds and the human
mind is based on this analysis. The physiological doctrine that the heart is
the organ of one department of mind is offset by the clear statement that the
remaining factors of mind reside in the brain. This early recognition of
brain as the organ of mind must not be forgotten in our later studies. It
should be recalled, however, that a Crotonian physician, Alemaean, a
younger contemporary of Pythagoras, is also credited with the same theory.
(7) A knowledge of anatomy is at least vaguely foreshadowed in the
assertion that veins, arteries, and nerves are the links of the soul. In this
connection it should be recalled that Pythagoras was a practical physician.
As against these scientific doctrines, however, some of them being at
least remarkable guesses at the truth, attention must be called to the
concluding paragraph of our quotation, in which the old familiar
daemonology is outlined, quite after the Oriental fashion. We shall have
occasion to say more as to this phase of the subject later on. Meantime,
before leaving Pythagoras, let us note that his practical studies of humanity
led him to assert the doctrine that "the property of friends is common, and
that friendship is equality." His disciples, we are told, used to put all their
possessions together in one store and use them in common. Here, then,
seemingly, is the doctrine of communism put to the test of experiment at
this early day. If it seem that reference to this carries us beyond the bounds
of science, it may be replied that questions such as this will not lie beyond
the bounds of the science of the near future.
XENOPHANES AND PARMENIDES
There is a whimsical tale about Pythagoras, according to which the
philosopher was wont to declare that in an earlier state he had visited
Hades, and had there seen Homer and Hesiod tortured because of the absurd
things they had said about the gods. Apocrypbal or otherwise, the tale
suggests that Pythagoras was an agnostic as regards the current Greek
religion of his time. The same thing is perhaps true of most of the great
thinkers of this earliest period. But one among them was remembered in
later times as having had a peculiar aversion to the anthropomorphic
conceptions of his fellows. This was Xenophanes, who was born at
Colophon probably about the year 580 B.C., and who, after a life of

wandering, settled finally in Italy and became the founder of the so-called
Eleatic School.
A few fragments of the philosophical poem in which Xenophanes
expressed his views have come down to us, and these fragments include a
tolerably definite avowal of his faith. "God is one supreme among gods and
men, and not like mortals in body or in mind," says Xenophanes. Again he
asserts that "mortals suppose that the gods are born (as they themselves
are), that they wear man's clothing and have human voice and body; but,"
he continues, "if cattle or lions had hands so as to paint with their hands and
produce works of art as men do, they would paint their gods and give them
bodies in form like their own—horses like horses, cattle like cattle."
Elsewhere he says, with great acumen: "There has not been a man, nor will
there be, who knows distinctly what I say about the gods or in regard to all
things. For even if one chance for the most part to say what is true, still he
would not know; but every one thinks that he knows."(6)
In the same spirit Xenophanes speaks of the battles of Titans, of giants,
and of centaurs as "fictions of former ages." All this tells of the questioning
spirit which distinguishes the scientific investigator. Precisely whither this
spirit led him we do not know, but the writers of a later time have preserved
a tradition regarding a belief of Xenophanes that perhaps entitles him to be
considered the father of geology. Thus Hippolytus records that Xenophanes
studied the fossils to be found in quarries, and drew from their observation
remarkable conclusions. His words are as follows: "Xenophanes believes
that once the earth was mingled with the sea, but in the course of time it
became freed from moisture; and his proofs are such as these: that shells are
found in the midst of the land and among the mountains, that in the quarries
of Syracuse the imprints of a fish and of seals had been found, and in Paros
the imprint of an anchovy at some depth in the stone, and in Melite shallow
impressions of all sorts of sea products. He says that these imprints were
made when everything long ago was covered with mud, and then the
imprint dried in the mud. Further, he says that all men will be destroyed
when the earth sinks into the sea and becomes mud, and that the race will
begin anew from the beginning; and this transformation takes place for all
worlds."(7) Here, then, we see this earliest of paleontologists studying the
fossil-bearing strata of the earth, and drawing from his observations a
marvellously scientific induction. Almost two thousand years later another
famous citizen of Italy, Leonardo da Vinci, was independently to think out

similar conclusions from like observations. But not until the nineteenth
century of our era, some twenty-four hundred years after the time of
Xenophanes, was the old Greek's doctrine to be accepted by the scientific
world. The ideas of Xenophanes were known to his contemporaries and, as
we see, quoted for a few centuries by his successors, then they were ignored
or quite forgotten; and if any philosopher of an ensuing age before the time
of Leonardo championed a like rational explanation of the fossils, we have
no record of the fact. The geological doctrine of Xenophanes, then, must be
listed among those remarkable Greek anticipations of nineteenth-century
science which suffered almost total eclipse in the intervening centuries.
Among the pupils of Xenophanes was Parmenides, the thinker who was
destined to carry on the work of his master along the same scientific lines,
though at the same time mingling his scientific conceptions with the
mysticism of the poet. We have already had occasion to mention that
Parmenides championed the idea that the earth is round; noting also that
doubts exist as to whether he or Pythagoras originated this doctrine. No
explicit answer to this question can possibly be hoped for. It seems clear,
however, that for a long time the Italic School, to which both these
philosophers belonged, had a monopoly of the belief in question.
Parmenides, like Pythagoras, is credited with having believed in the motion
of the earth, though the evidence furnished by the writings of the
philosopher himself is not as demonstrative as one could wish.
Unfortunately, the copyists of a later age were more concerned with
metaphysical speculations than with more tangible things. But as far as the
fragmentary references to the ideas of Parmenides may be accepted, they do
not support the idea of the earth's motion. Indeed, Parmenides is made to
say explicitly, in preserved fragments, that "the world is immovable,
limited, and spheroidal in form."(8)
Nevertheless, some modern interpreters have found an opposite meaning
in Parmenides. Thus Ritter interprets him as supposing "that the earth is in
the centre spherical, and maintained in rotary motion by its equiponderance;
around it lie certain rings, the highest composed of the rare element fire, the
next lower a compound of light and darkness, and lowest of all one wholly
of night, which probably indicated to his mind the surface of the earth, the
centre of which again he probably considered to be fire."(9) But this, like
too many interpretations of ancient thought, appears to read into the
fragments ideas which the words themselves do not warrant. There seems

no reason to doubt, however, that Parmenides actually held the doctrine of
the earth's sphericity. Another glimpse of his astronomical doctrines is
furnished us by a fragment which tells us that he conceived the morning and
the evening stars to be the same, a doctrine which, as we have seen, was
ascribed also to Pythagoras. Indeed, we may repeat that it is quite
impossible to distinguish between the astronomical doctrines of these two
philosophers.

The poem of Parmenides in which the cosmogonic speculations occur
treats also of the origin of man. The author seems to have had a clear
conception that intelligence depends on bodily organism, and that the
more elaborately developed the organism the higher the intelligence.
But in the interpretation of this thought we are hampered by the
characteristic vagueness of expression, which may best be evidenced by
putting before the reader two English translations of the same stanza.
Here is Ritter's rendering, as made into English by his translator,
Morrison:

"For exactly as each has the state of his limbs many-jointed,
So invariably stands it with men in their mind and their reason; For the
system of limbs is that which thinketh in mankind Alike in all and in
each: for thought is the fulness."(10)

The same stanza is given thus by George Henry Lewes:

"Such as to each man is the nature of his many-jointed limbs,
Such also is the intelligence of each man; for it is The nature of limbs
(organization) which thinketh in men, Both in one and in all; for the
highest degree of organization gives the highest degree of thought."(11)

Here it will be observed that there is virtual agreement between the
translators except as to the last clause, but that clause is most essential. The
Greek phrase is (gr to gar pleon esti nohma). Ritter, it will be observed,
renders this, "for thought is the fulness." Lewes paraphrases it, "for the
highest degree of organization gives the highest degree of thought." The
difference is intentional, since Lewes himself criticises the translation of
Ritter. Ritter's translation is certainly the more literal, but the fact that such
diversity is possible suggests one of the chief elements of uncertainty that
hamper our interpretation of the thought of antiquity. Unfortunately, the
mind of the commentator has usually been directed towards such subtleties,
rather than towards the expression of precise knowledge. Hence it is that the
philosophers of Greece are usually thought of as mere dreamers, and that
their true status as scientific discoverers is so often overlooked. With these
intangibilities we have no present concern beyond this bare mention; for us
it suffices to gain as clear an idea as we may of the really scientific

conceptions of these thinkers, leaving the subtleties of their deductive
reasoning for the most part untouched.
EMPEDOCLES
The latest of the important pre-Socratic philosophers of the Italic school
was Empedocles, who was born about 494 B.C. and lived to the age of
sixty. These dates make Empedocles strictly contemporary with
Anaxagoras, a fact which we shall do well to bear in mind when we come
to consider the latter's philosophy in the succeeding chapter. Like
Pythagoras, Empedocles is an imposing figure. Indeed, there is much of
similarity between the personalities, as between the doctrines, of the two
men. Empedocles, like Pythagoras, was a physician; like him also he was
the founder of a cult. As statesman, prophet, physicist, physician, reformer,
and poet he showed a versatility that, coupled with profundity, marks the
highest genius. In point of versatility we shall perhaps hardly find his equal
at a later day—unless, indeed, an exception be made of Eratosthenes. The
myths that have grown about the name of Empedocles show that he was a
remarkable personality. He is said to have been an awe-inspiring figure,
clothing himself in Oriental splendor and moving among mankind as a
superior being. Tradition has it that he threw himself into the crater of a
volcano that his otherwise unexplained disappearance might lead his
disciples to believe that he had been miraculously translated; but tradition
goes on to say that one of the brazen slippers of the philosopher was thrown
up by the volcano, thus revealing his subterfuge. Another tradition of far
more credible aspect asserts that Empedocles retreated from Italy, returning
to the home of his fathers in Peloponnesus to die there obscurely. It seems
odd that the facts regarding the death of so great a man, at so comparatively
late a period, should be obscure; but this, perhaps, is in keeping with the
personality of the man himself. His disciples would hesitate to ascribe a
merely natural death to so inspired a prophet.
Empedocles appears to have been at once an observer and a dreamer. He
is credited with noting that the pressure of air will sustain the weight of
water in an inverted tube; with divining, without the possibility of proof,
that light has actual motion in space; and with asserting that centrifugal
motion must keep the heavens from falling. He is credited with a great
sanitary feat in the draining of a marsh, and his knowledge of medicine was
held to be supernatural. Fortunately, some fragments of the writings of

Empedocles have come down to us, enabling us to judge at first hand as to
part of his doctrines; while still more is known through the references made
to him by Plato, Aristotle, and other commentators. Empedocles was a poet
whose verses stood the test of criticism. In this regard he is in a like
position with Parmenides; but in neither case are the preserved fragments
sufficient to enable us fully to estimate their author's scientific attainments.
Philosophical writings are obscure enough at the best, and they perforce
become doubly so when expressed in verse. Yet there are certain passages
of Empedocles that are unequivocal and full of interest. Perhaps the most
important conception which the works of Empedocles reveal to us is the
denial of anthropomorphism as applied to deity. We have seen how early the
anthropomorphic conception was developed and how closely it was all
along clung to; to shake the mind free from it then was a remarkable feat, in
accomplishing which Empedocles took a long step in the direction of
rationalism. His conception is paralleled by that of another physician,
Alcmaeon, of Proton, who contended that man's ideas of the gods amounted
to mere suppositions at the very most. A rationalistic or sceptical tendency
has been the accompaniment of medical training in all ages.
The words in which Empedocles expresses his conception of deity have
been preserved and are well worth quoting: "It is not impossible," he says,
"to draw near (to god) even with the eyes or to take hold of him with our
hands, which in truth is the best highway of persuasion in the mind of man;
for he has no human head fitted to a body, nor do two shoots branch out
from the trunk, nor has he feet, nor swift legs, nor hairy parts, but he is
sacred and ineffable mind alone, darting through the whole world with swift
thoughts."(8)
How far Empedocles carried his denial of anthropomorphism is
illustrated by a reference of Aristotle, who asserts "that Empedocles regards
god as most lacking in the power of perception; for he alone does not know
one of the elements, Strife (hence), of perishable things." It is difficult to
avoid the feeling that Empedocles here approaches the modern
philosophical conception that God, however postulated as immutable, must
also be postulated as unconscious, since intelligence, as we know it, is
dependent upon the transmutations of matter. But to urge this thought would
be to yield to that philosophizing tendency which has been the bane of
interpretation as applied to the ancient thinkers.

Considering for a moment the more tangible accomplishments of
Empedocles, we find it alleged that one of his "miracles" consisted of the
preservation of a dead body without putrefaction for some weeks after
death. We may assume from this that he had gained in some way a
knowledge of embalming. As he was notoriously fond of experiment, and as
the body in question (assuming for the moment the authenticity of the
legend) must have been preserved without disfigurement, it is conceivable
even that he had hit upon the idea of injecting the arteries. This, of course,
is pure conjecture; yet it finds a certain warrant, both in the fact that the
words of Pythagoras lead us to believe that the arteries were known and
studied, and in the fact that Empedocles' own words reveal him also as a
student of the vascular system. Thus Plutarch cites Empedocles as believing
"that the ruling part is not in the head or in the breast, but in the blood;
wherefore in whatever part of the body the more of this is spread in that part
men excel."(13) And Empedocles' own words, as preserved by Stobaeus,
assert "(the heart) lies in seas of blood which dart in opposite directions,
and there most of all intelligence centres for men; for blood about the heart
is intelligence in the case of man." All this implies a really remarkable
appreciation of the dependence of vital activities upon the blood.
This correct physiological conception, however, was by no means the
most remarkable of the ideas to which Empedoeles was led by his
anatomical studies. His greatest accomplishment was to have conceived and
clearly expressed an idea which the modern evolutionist connotes when he
speaks of homologous parts—an idea which found a famous modern
expositor in Goethe, as we shall see when we come to deal with eighteenth-
century science. Empedocles expresses the idea in these words: "Hair, and
leaves, and thick feathers of birds, are the same thing in origin, and reptile
scales too on strong limbs. But on hedgehogs sharp-pointed hair bristles on
their backs."(14) That the idea of transmutation of parts, as well as of mere
homology, was in mind is evidenced by a very remarkable sentence in
which Aristotle asserts, "Empedocles says that fingernails rise from sinew
from hardening." Nor is this quite all, for surely we find the germ of the
Lamarckian conception of evolution through the transmission of acquired
characters in the assertion that "many characteristics appear in animals
because it happened to be thus in their birth, as that they have such a spine
because they happen to be descended from one that bent itself backward."
(15) Aristotle, in quoting this remark, asserts, with the dogmatism which

characterizes the philosophical commentators of every age, that
"Empedocles is wrong," in making this assertion; but Lamarck, who lived
twenty-three hundred years after Empedocles, is famous in the history of
the doctrine of evolution for elaborating this very idea.
It is fair to add, however, that the dreamings of Empedocles regarding the
origin of living organisms led him to some conceptions that were much less
luminous. On occasion, Empedocles the poet got the better of Empedocles
the scientist, and we are presented with a conception of creation as
grotesque as that which delighted the readers of Paradise Lost at a later day.
Empedocles assures us that "many heads grow up without necks, and arms
were wandering about, necks bereft of shoulders, and eyes roamed about
alone with no foreheads."(16) This chaotic condition, so the poet dreamed,
led to the union of many incongruous parts, producing "creatures with
double faces, offspring of oxen with human faces, and children of men with
oxen heads." But out of this chaos came, finally, we are led to infer, a
harmonious aggregation of parts, producing ultimately the perfected
organisms that we see. Unfortunately the preserved portions of the writings
of Empedocles do not enlighten us as to the precise way in which final
evolution was supposed to be effected; although the idea of endless
experimentation until natural selection resulted in survival of the fittest
seems not far afield from certain of the poetical assertions. Thus: "As
divinity was mingled yet more with divinity, these things (the various
members) kept coming together in whatever way each might chance."
Again: "At one time all the limbs which form the body united into one by
love grew vigorously in the prime of life; but yet at another time, separated
by evil Strife, they wander each in different directions along the breakers of
the sea of life. Just so is it with plants, and with fishes dwelling in watery
halls, and beasts whose lair is in the mountains, and birds borne on wings."
(17)
All this is poetry rather than science, yet such imaginings could come
only to one who was groping towards what we moderns should term an
evolutionary conception of the origins of organic life; and however
grotesque some of these expressions may appear, it must be admitted that
the morphological ideas of Empedocles, as above quoted, give the Sicilian
philosopher a secure place among the anticipators of the modern
evolutionist.

VII. GREEK SCIENCE IN THE EARLY ATTIC
PERIOD
We have travelled rather far in our study of Greek science, and yet we
have not until now come to Greece itself. And even now, the men whose
names we are to consider were, for the most part, born in out-lying portions
of the empire; they differed from the others we have considered only in the
fact that they were drawn presently to the capital. The change is due to a
most interesting sequence of historical events. In the day when Thales and
his immediate successors taught in Miletus, when the great men of the Italic
school were in their prime, there was no single undisputed Centre of Greek
influence. The Greeks were a disorganized company of petty nations,
welded together chiefly by unity of speech; but now, early in the fifth
century B.C., occurred that famous attack upon the Western world by the
Persians under Darius and his son and successor Xerxes. A few months of
battling determined the fate of the Western world. The Orientals were
hurled back; the glorious memories of Marathon, Salamis, and Plataea
stimulated the patriotism and enthusiasm of all children of the Greek race.
The Greeks, for the first time, occupied the centre of the historical stage; for
the brief interval of about half a century the different Grecian principalities
lived together in relative harmony. One city was recognized as the
metropolis of the loosely bound empire; one city became the home of
culture and the Mecca towards which all eyes turned; that city, of course,
was Athens. For a brief time all roads led to Athens, as, at a later date, they
all led to Rome. The waterways which alone bound the widely scattered
parts of Hellas into a united whole led out from Athens and back to Athens,
as the spokes of a wheel to its hub. Athens was the commercial centre, and,
largely for that reason, it became the centre of culture and intellectual
influence also. The wise men from the colonies visited the metropolis, and
the wise Athenians went out to the colonies. Whoever aspired to become a
leader in politics, in art, in literature, or in philosophy, made his way to the
capital, and so, with almost bewildering suddenness, there blossomed the
civilization of the age of Pericles; the civilization which produced

aeschylus, Sophocles, Euripides, Herodotus, and Thucydides; the
civilization which made possible the building of the Parthenon.
ANAXAGORAS
Sometime during the early part of this golden age there came to Athens a
middle-aged man from Clazomenae, who, from our present stand-point,
was a more interesting personality than perhaps any other in the great
galaxy of remarkable men assembled there. The name of this new-comer
was Anaxagoras. It was said in after-time, we know not with what degree of
truth, that he had been a pupil of Anaximenes. If so, he was a pupil who
departed far from the teachings of his master. What we know for certain is
that Anaxagoras was a truly original thinker, and that he became a close
friend—in a sense the teacher—of Pericles and of Euripides. Just how long
he remained at Athens is not certain; but the time came when he had made
himself in some way objectionable to the Athenian populace through his
teachings. Filled with the spirit of the investigator, he could not accept the
current conceptions as to the gods. He was a sceptic, an innovator. Such
men are never welcome; they are the chief factors in the progress of
thought, but they must look always to posterity for recognition of their
worth; from their contemporaries they receive, not thanks, but persecution.
Sometimes this persecution takes one form, sometimes another; to the credit
of the Greeks be it said, that with them it usually led to nothing more severe
than banishment. In the case of Anaxagoras, it is alleged that the sentence
pronounced was death; but that, thanks to the influence of Pericles, this
sentence was commuted to banishment. In any event, the aged philosopher
was sent away from the city of his adoption. He retired to Lampsacus. "It is
not I that have lost the Athenians," he said; "it is the Athenians that have
lost me."
The exact position which Anaxagoras had among his contemporaries, and
his exact place in the development of philosophy, have always been
somewhat in dispute. It is not known, of a certainty, that he even held an
open school at Athens. Ritter thinks it doubtful that he did. It was his fate to
be misunderstood, or underestimated, by Aristotle; that in itself would have
sufficed greatly to dim his fame—might, indeed, have led to his almost
entire neglect had he not been a truly remarkable thinker. With most of the
questions that have exercised the commentators we have but scant concern.
Following Aristotle, most historians of philosophy have been

metaphysicians; they have concerned themselves far less with what the
ancient thinkers really knew than with what they thought. A chance using of
a verbal quibble, an esoteric phrase, the expression of a vague mysticism—
these would suffice to call forth reams of exposition. It has been the favorite
pastime of historians to weave their own anachronistic theories upon the
scanty woof of the half-remembered thoughts of the ancient philosophers.
To make such cloth of the imagination as this is an alluring pastime, but one
that must not divert us here. Our point of view reverses that of the
philosophers. We are chiefly concerned, not with some vague saying of
Anaxagoras, but with what he really knew regarding the phenomena of
nature; with what he observed, and with the comprehensible deductions that
he derived from his observations. In attempting to answer these inquiries,
we are obliged, in part, to take our evidence at second-hand; but,
fortunately, some fragments of writings of Anaxagoras have come down to
us. We are told that he wrote only a single book. It was said even (by
Diogenes) that he was the first man that ever wrote a work in prose. The
latter statement would not bear too close an examination, yet it is true that
no extensive prose compositions of an earlier day than this have been
preserved, though numerous others are known by their fragments.
Herodotus, "the father of prose," was a slightly younger contemporary of
the Clazomenaean philosopher; not unlikely the two men may have met at
Athens.
Notwithstanding the loss of the greater part of the writings of
Anaxagoras, however, a tolerably precise account of his scientific doctrines
is accessible. Diogenes Laertius expresses some of them in very clear and
precise terms. We have already pointed out the uncertainty that attaches to
such evidence as this, but it is as valid for Anaxagoras as for another. If we
reject such evidence, we shall often have almost nothing left; in accepting it
we may at least feel certain that we are viewing the thinker as his
contemporaries and immediate successors viewed him. Following
Diogenes, then, we shall find some remarkable scientific opinions ascribed
to Anaxagoras. "He asserted," we are told, "that the sun was a mass of
burning iron, greater than Peloponnesus, and that the moon contained
houses and also hills and ravines." In corroboration of this, Plato represents
him as having conjectured the right explanation of the moon's light, and of
the solar and lunar eclipses. He had other astronomical theories that were
more fanciful; thus "he said that the stars originally moved about in

irregular confusion, so that at first the pole-star, which is continually
visible, always appeared in the zenith, but that afterwards it acquired a
certain declination, and that the Milky Way was a reflection of the light of
the sun when the stars did not appear. The comets he considered to be a
concourse of planets emitting rays, and the shooting-stars he thought were
sparks, as it were, leaping from the firmament."
Much of this is far enough from the truth, as we now know it, yet all of it
shows an earnest endeavor to explain the observed phenomena of the
heavens on rational principles. To have predicated the sun as a great molten
mass of iron was indeed a wonderful anticipation of the results of the
modern spectroscope. Nor can it be said that this hypothesis of Anaxagoras
was a purely visionary guess. It was in all probability a scientific deduction
from the observed character of meteoric stones. Reference has already been
made to the alleged prediction of the fall of the famous meteor at
aegespotomi by Anaxagoras. The assertion that he actually predicted this
fall in any proper sense of the word would be obviously absurd. Yet the fact
that his name is associated with it suggests that he had studied similar
meteorites, or else that he studied this particular one, since it is not quite
clear whether it was before or after this fall that he made the famous
assertion that space is full of falling stones. We should stretch the
probabilities were we to assert that Anaxagoras knew that shooting-stars
and meteors were the same, yet there is an interesting suggestiveness in his
likening the shooting-stars to sparks leaping from the firmament, taken in
connection with his observation on meteorites. Be this as it may, the fact
that something which falls from heaven as a blazing light turns out to be an
iron-like mass may very well have suggested to the most rational of
thinkers that the great blazing light called the sun has the same composition.
This idea grasped, it was a not unnatural extension to conceive the other
heavenly bodies as having the same composition.
This led to a truly startling thought. Since the heavenly bodies are of the
same composition as the earth, and since they are observed to be whirling
about the earth in space, may we not suppose that they were once a part of
the earth itself, and that they have been thrown off by the force of a
whirling motion? Such was the conclusion which Anaxagoras reached; such
his explanation of the origin of the heavenly bodies. It was a marvellous
guess. Deduct from it all that recent science has shown to be untrue; bear in
mind that the stars are suns, compared with which the earth is a mere speck

of dust; recall that the sun is parent, not daughter, of the earth, and despite
all these deductions, the cosmogonic guess of Anaxagoras remains, as it
seems to us, one of the most marvellous feats of human intelligence. It was
the first explanation of the cosmic bodies that could be called, in any sense,
an anticipation of what the science of our own day accepts as a true
explanation of cosmic origins. Moreover, let us urge again that this was no
mere accidental flight of the imagination; it was a scientific induction based
on the only data available; perhaps it is not too much to say that it was the
only scientific induction which these data would fairly sustain. Of course it
is not for a moment to be inferred that Anaxagoras understood, in the
modern sense, the character of that whirling force which we call centrifugal.
About two thousand years were yet to elapse before that force was
explained as elementary inertia; and even that explanation, let us not forget,
merely sufficed to push back the barriers of mystery by one other stage; for
even in our day inertia is a statement of fact rather than an explanation.
But however little Anaxagoras could explain the centrifugal force on
mechanical principles, the practical powers of that force were sufficiently
open to his observation. The mere experiment of throwing a stone from a
sling would, to an observing mind, be full of suggestiveness. It would be
obvious that by whirling the sling about, the stone which it held would be
sustained in its circling path about the hand in seeming defiance of the
earth's pull, and after the stone had left the sling, it could fly away from the
earth to a distance which the most casual observation would prove to be
proportionate to the speed of its flight. Extremely rapid motion, then, might
project bodies from the earth's surface off into space; a sufficiently rapid
whirl would keep them there. Anaxagoras conceived that this was precisely
what had occurred. His imagination even carried him a step farther—to a
conception of a slackening of speed, through which the heavenly bodies
would lose their centrifugal force, and, responding to the perpetual pull of
gravitation, would fall back to the earth, just as the great stone at
aegespotomi had been observed to do.
Here we would seem to have a clear conception of the idea of universal
gravitation, and Anaxagoras stands before us as the anticipator of Newton.
Were it not for one scientific maxim, we might exalt the old Greek above
the greatest of modern natural philosophers; but that maxim bids us pause.
It is phrased thus, "He discovers who proves." Anaxagoras could not prove;
his argument was at best suggestive, not demonstrative. He did not even

know the laws which govern falling bodies; much less could he apply such
laws, even had he known them, to sidereal bodies at whose size and
distance he could only guess in the vaguest terms. Still his cosmogonic
speculation remains as perhaps the most remarkable one of antiquity. How
widely his speculation found currency among his immediate successors is
instanced in a passage from Plato, where Socrates is represented as
scornfully answering a calumniator in these terms: "He asserts that I say the
sun is a stone and the moon an earth. Do you think of accusing Anaxagoras,
Miletas, and have you so low an opinion of these men, and think them so
unskilled in laws, as not to know that the books of Anaxagoras the
Clazomenaean are full of these doctrines. And forsooth the young men are
learning these matters from me which sometimes they can buy from the
orchestra for a drachma, at the most, and laugh at Socrates if he pretends
they are his-particularly seeing they are so strange."
The element of error contained in these cosmogonic speculations of
Anaxagoras has led critics to do them something less than justice. But there
is one other astronomical speculation for which the Clazomenaean
philosopher has received full credit. It is generally admitted that it was he
who first found out the explanation of the phases of the moon; a knowledge
that that body shines only by reflected light, and that its visible forms,
waxing and waning month by month from crescent to disk and from disk to
crescent, merely represent our shifting view of its sun-illumined face. It is
difficult to put ourselves in the place of the ancient observer and realize
how little the appearances suggest the actual fact. That a body of the same
structure as the earth should shine with the radiance of the moon merely
because sunlight is reflected from it, is in itself a supposition seemingly
contradicted by ordinary experience. It required the mind of a philosopher,
sustained, perhaps, by some experimental observations, to conceive the idea
that what seems so obviously bright may be in reality dark. The germ of the
conception of what the philosopher speaks of as the noumena, or actualities,
back of phenomena or appearances, had perhaps this crude beginning.
Anaxagoras could surely point to the moon in support of his seeming
paradox that snow, being really composed of water, which is dark, is in
reality black and not white—a contention to which we shall refer more at
length in a moment.
But there is yet another striking thought connected with this new
explanation of the phases of the moon. The explanation implies not merely

the reflection of light by a dark body, but by a dark body of a particular
form. Granted that reflections are in question, no body but a spherical one
could give an appearance which the moon presents. The moon, then, is not
merely a mass of earth, it is a spherical mass of earth. Here there were no
flaws in the reasoning of Anaxagoras. By scientific induction he passed
from observation to explanation. A new and most important element was
added to the science of astronomy.
Looking back from the latter-day stand-point, it would seem as if the
mind of the philosopher must have taken one other step: the mind that had
conceived sun, moon, stars, and earth to be of one substance might
naturally, we should think, have reached out to the further induction that,
since the moon is a sphere, the other cosmic bodies, including the earth,
must be spheres also. But generalizer as he was, Anaxagoras was too rigidly
scientific a thinker to make this assumption. The data at his command did
not, as he analyzed them, seem to point to this conclusion. We have seen
that Pythagoras probably, and Parmenides surely, out there in Italy had
conceived the idea of the earth's rotundity, but the Pythagorean doctrines
were not rapidly taken up in the mother-country, and Parmenides, it must be
recalled, was a strict contemporary of Anaxagoras himself. It is no
reproach, therefore, to the Clazomenaean philosopher that he should have
held to the old idea that the earth is flat, or at most a convex disk—the latter
being the Babylonian conception which probably dominated that Milesian
school to which Anaxagoras harked back.
Anaxagoras may never have seen an eclipse of the moon, and even if he
had he might have reflected that, from certain directions, a disk may throw
precisely the same shadow as a sphere. Moreover, in reference to the
shadow cast by the earth, there was, so Anaxagoras believed, an observation
open to him nightly which, we may well suppose, was not without influence
in suggesting to his mind the probable shape of the earth. The Milky Way,
which doubtless had puzzled astronomers from the beginnings of history
and which was to continue to puzzle them for many centuries after the day
of Anaxagoras, was explained by the Clazomenaean philosopher on a
theory obviously suggested by the theory of the moon's phases. Since the
earth-like moon shines by reflected light at night, and since the stars seem
obviously brighter on dark nights, Anaxagoras was but following up a
perfectly logical induction when he propounded the theory that the stars in
the Milky Way seem more numerous and brighter than those of any other

part of the heavens, merely because the Milky Way marks the shadow of the
earth. Of course the inference was wrong, so far as the shadow of the earth
is concerned; yet it contained a part truth, the force of which was never
fully recognized until the time of Galileo. This consists in the assertion that
the brightness of the Milky Way is merely due to the glow of many stars.
The shadow-theory of Anaxagoras would naturally cease to have validity so
soon as the sphericity of the earth was proved, and with it, seemingly, fell
for the time the companion theory that the Milky Way is made up of a
multitude of stars.
It has been said by a modern critic(1) that the shadow-theory was
childish in that it failed to note that the Milky Way does not follow the
course of the ecliptic. But this criticism only holds good so long as we
reflect on the true character of the earth as a symmetrical body poised in
space. It is quite possible to conceive a body occupying the position of the
earth with reference to the sun which would cast a shadow having such a
tenuous form as the Milky Way presents. Such a body obviously would not
be a globe, but a long-drawn-out, attenuated figure. There is, to be sure, no
direct evidence preserved to show that Anaxagoras conceived the world to
present such a figure as this, but what we know of that philosopher's close-
reasoning, logical mind gives some warrant to the assumption—gratuitous
though in a sense it be—that the author of the theory of the moon's phases
had not failed to ask himself what must be the form of that terrestrial body
which could cast the tenuous shadow of the Milky Way. Moreover, we must
recall that the habitable earth, as known to the Greeks of that day, was a
relatively narrow band of territory, stretching far to the east and to the west.
Anaxagoras as Meteorologist
The man who had studied the meteorite of aegospotami, and been put by
it on the track of such remarkable inductions, was, naturally, not oblivious
to the other phenomena of the atmosphere. Indeed, such a mind as that of
Anaxagoras was sure to investigate all manner of natural phenomena, and
almost equally sure to throw new light on any subject that it investigated.
Hence it is not surprising to find Anaxagoras credited with explaining the
winds as due to the rarefactions of the atmosphere produced by the sun.
This explanation gives Anaxagoras full right to be called "the father of
meteorology," a title which, it may be, no one has thought of applying to
him, chiefly because the science of meteorology did not make its real

beginnings until some twenty-four hundred years after the death of its first
great votary. Not content with explaining the winds, this prototype of
Franklin turned his attention even to the tipper atmosphere. "Thunder," he is
reputed to have said, "was produced by the collision of the clouds, and
lightning by the rubbing together of the clouds." We dare not go so far as to
suggest that this implies an association in the mind of Anaxagoras between
the friction of the clouds and the observed electrical effects generated by the
friction of such a substance as amber. To make such a suggestion doubtless
would be to fall victim to the old familiar propensity to read into Homer
things that Homer never knew. Yet the significant fact remains that
Anaxagoras ascribed to thunder and to lightning their true position as
strictly natural phenomena. For him it was no god that menaced humanity
with thundering voice and the flash of his divine fires from the clouds.
Little wonder that the thinker whose science carried him to such scepticism
as this should have felt the wrath of the superstitious Athenians.
Biological Speculations
Passing from the phenomena of the air to those of the earth itself, we
learn that Anaxagoras explained an earthquake as being produced by the
returning of air into the earth. We cannot be sure as to the exact meaning
here, though the idea that gases are imprisoned in the substance of the earth
seems not far afield. But a far more remarkable insight than this would
imply was shown by Anaxagoras when he asserted that a certain amount of
air is contained in water, and that fishes breathe this air. The passage of
Aristotle in which this opinion is ascribed to Anaxagoras is of sufficient
interest to be quoted at length:
"Democritus, of Abdera," says Aristotle, "and some others, that have
spoken concerning respiration, have determined nothing concerning other
animals, but seem to have supposed that all animals respire. But
Anaxagoras and Diogenes (Apolloniates), who say that all animals respire,
have also endeavored to explain how fishes, and all those animals that have
a hard, rough shell, such as oysters, mussels, etc., respire. And Anaxagoras,
indeed, says that fishes, when they emit water through their gills, attract air
from the mouth to the vacuum in the viscera from the water which
surrounds the mouth; as if air was inherent in the water."(2)
It should be recalled that of the three philosophers thus mentioned as
contending that all animals respire, Anaxagoras was the elder; he, therefore,

was presumably the originator of the idea. It will be observed, too, that
Anaxagoras alone is held responsible for the idea that fishes respire air
through their gills, "attracting" it from the water. This certainly was one of
the shrewdest physiological guesses of any age, if it be regarded as a mere
guess. With greater justice we might refer to it as a profound deduction
from the principle of the uniformity of nature.
In making such a deduction, Anaxagoras was far in advance of his time
as illustrated by the fact that Aristotle makes the citation we have just
quoted merely to add that "such things are impossible," and to refute these
"impossible" ideas by means of metaphysical reasonings that seemed
demonstrative not merely to himself, but to many generations of his
followers.
We are told that Anaxagoras alleged that all animals were originally
generated out of moisture, heat, and earth particles. Just what opinion he
held concerning man's development we are not informed. Yet there is one of
his phrases which suggests—without, perhaps, quite proving—that he was
an evolutionist. This phrase asserts, with insight that is fairly startling, that
man is the most intelligent of animals because he has hands. The man who
could make that assertion must, it would seem, have had in mind the idea of
the development of intelligence through the use of hands—an idea the full
force of which was not evident to subsequent generations of thinkers until
the time of Darwin.
Physical Speculations
Anaxagoras is cited by Aristotle as believing that "plants are animals and
feel pleasure and pain, inferring this because they shed their leaves and let
them grow again." The idea is fanciful, yet it suggests again a truly
philosophical conception of the unity of nature. The man who could
conceive that idea was but little hampered by traditional conceptions. He
was exercising a rare combination of the rigidly scientific spirit with the
poetical imagination. He who possesses these gifts is sure not to stop in his
questionings of nature until he has found some thinkable explanation of the
character of matter itself. Anaxagoras found such an explanation, and, as
good luck would have it, that explanation has been preserved. Let us
examine his reasoning in some detail. We have already referred to the claim
alleged to have been made by Anaxagoras that snow is not really white, but
black. The philosopher explained his paradox, we are told, by asserting that

snow is really water, and that water is dark, when viewed under proper
conditions—as at the bottom of a well. That idea contains the germ of the
Clazomenaean philosopher's conception of the nature of matter. Indeed, it is
not unlikely that this theory of matter grew out of his observation of the
changing forms of water. He seems clearly to have grasped the idea that
snow on the one hand, and vapor on the other, are of the same intimate
substance as the water from which they are derived and into which they
may be again transformed. The fact that steam and snow can be changed
back into water, and by simple manipulation cannot be changed into any
other substance, finds, as we now believe, its true explanation in the fact
that the molecular structure, as we phrase it—that is to say, the ultimate
particle of which water is composed, is not changed, and this is precisely
the explanation which Anaxagoras gave of the same phenomena. For him
the unit particle of water constituted an elementary body, uncreated,
unchangeable, indestructible. This particle, in association with like
particles, constitutes the substance which we call water. The same particle
in association with particles unlike itself, might produce totally different
substances—as, for example, when water is taken up by the roots of a plant
and becomes, seemingly, a part of the substance of the plant. But whatever
the changed association, so Anaxagoras reasoned, the ultimate particle of
water remains a particle of water still. And what was true of water was true
also, so he conceived, of every other substance. Gold, silver, iron, earth, and
the various vegetables and animal tissues—in short, each and every one of
all the different substances with which experience makes us familiar, is
made up of unit particles which maintain their integrity in whatever
combination they may be associated. This implies, obviously, a multitude of
primordial particles, each one having an individuality of its own; each one,
like the particle of water already cited, uncreated, unchangeable, and
indestructible.
Fortunately, we have the philosopher's own words to guide us as to his
speculations here. The fragments of his writings that have come down to us
(chiefly through the quotations of Simplicius) deal almost exclusively with
these ultimate conceptions of his imagination. In ascribing to him, then, this
conception of diverse, uncreated, primordial elements, which can never be
changed, but can only be mixed together to form substances of the material
world, we are not reading back post-Daltonian knowledge into the system
of Anaxagoras. Here are his words: "The Greeks do not rightly use the

terms 'coming into being' and 'perishing.' For nothing comes into being, nor,
yet, does anything perish; but there is mixture and separation of things that
are. So they would do right in calling 'coming into being' 'mixture' and
'perishing' 'separation.' For how could hair come from what is not hair? Or
flesh from what is not flesh?"
Elsewhere he tells us that (at one stage of the world's development) "the
dense, the moist, the cold, the dark, collected there where now is earth; the
rare, the warm, the dry, the bright, departed towards the further part of the
aether. The earth is condensed out of these things that are separated, for
water is separated from the clouds, and earth from the water; and from the
earth stones are condensed by the cold, and these are separated farther from
the water." Here again the influence of heat and cold in determining
physical qualities is kept pre-eminently in mind. The dense, the moist, the
cold, the dark are contrasted with the rare, the warm, the dry, and bright;
and the formation of stones is spoken of as a specific condensation due to
the influence of cold. Here, then, we have nearly all the elements of the
Daltonian theory of atoms on the one hand, and the nebular hypothesis of
Laplace on the other. But this is not quite all. In addition to such diverse
elementary particles as those of gold, water, and the rest, Anaxagoras
conceived a species of particles differing from all the others, not merely as
they differ from one another, but constituting a class by themselves;
particles infinitely smaller than the others; particles that are described as
infinite, self-powerful, mixed with nothing, but existing alone. That is to
say (interpreting the theory in the only way that seems plausible), these
most minute particles do not mix with the other primordial particles to form
material substances in the same way in which these mixed with one another.
But, on the other hand, these "infinite, self-powerful, and unmixed"
particles commingle everywhere and in every substance whatever with the
mixed particles that go to make up the substances.
There is a distinction here, it will be observed, which at once suggests the
modern distinction between physical processes and chemical processes, or,
putting it otherwise, between molecular processes and atomic processes; but
the reader must be guarded against supposing that Anaxagoras had any such
thought as this in mind. His ultimate mixable particles can be compared
only with the Daltonian atom, not with the molecule of the modern
physicist, and his "infinite, self-powerful, and unmixable" particles are not
comparable with anything but the ether of the modern physicist, with which

hypothetical substance they have many points of resemblance. But the
"infinite, self-powerful, and unmixed" particles constituting thus an ether-
like plenum which permeates all material structures, have also, in the mind
of Anaxagoras, a function which carries them perhaps a stage beyond the
province of the modern ether. For these "infinite, self powerful, and
unmixed" particles are imbued with, and, indeed, themselves constitute,
what Anaxagoras terms nous, a word which the modern translator has
usually paraphrased as "mind." Neither that word nor any other available
one probably conveys an accurate idea of what Anaxagoras meant to imply
by the word nous. For him the word meant not merely "mind" in the sense
of receptive and comprehending intelligence, but directive and creative
intelligence as well. Again let Anaxagoras speak for himself: "Other things
include a portion of everything, but nous is infinite, and self-powerful, and
mixed with nothing, but it exists alone, itself by itself. For if it were not by
itself, but were mixed with anything else, it would include parts of all
things, if it were mixed with anything; for a portion of everything exists in
every thing, as has been said by me before, and things mingled with it
would prevent it from having power over anything in the same way that it
does now that it is alone by itself. For it is the most rarefied of all things
and the purest, and it has all knowledge in regard to everything and the
greatest power; over all that has life, both greater and less, nous rules. And
nous ruled the rotation of the whole, so that it set it in rotation in the
beginning. First it began the rotation from a small beginning, then more and
more was included in the motion, and yet more will be included. Both the
mixed and the separated and distinct, all things nous recognized. And
whatever things were to be, and whatever things were, as many as are now,
and whatever things shall be, all these nous arranged in order; and it
arranged that rotation, according to which now rotate stars and sun and
moon and air and aether, now that they are separated. Rotation itself caused
the separation, and the dense is separated from the rare, the warm from the
cold, the bright from the dark, the dry from the moist. And when nous
began to set things in motion, there was separation from everything that was
in motion, all this was made distinct. The rotation of the things that were
moved and made distinct caused them to be yet more distinct."(3)
Nous, then, as Anaxagoras conceives it, is "the most rarefied of all things,
and the purest, and it has knowledge in regard to everything and the greatest
power; over all that has life, both greater and less, it rules." But these are

postulants of omnipresence and omniscience. In other words, nous is
nothing less than the omnipotent artificer of the material universe. It lacks
nothing of the power of deity, save only that we are not assured that it
created the primordial particles. The creation of these particles was a
conception that for Anaxagoras, as for the modern Spencer, lay beyond the
range of imagination. Nous is the artificer, working with "uncreated"
particles. Back of nous and the particles lies, for an Anaxagoras as for a
Spencer, the Unknowable. But nous itself is the equivalent of that universal
energy of motion which science recognizes as operating between the
particles of matter, and which the theologist personifies as Deity. It is
Pantheistic deity as Anaxagoras conceives it; his may be called the first
scientific conception of a non-anthropomorphic god. In elaborating this
conception Anaxagoras proved himself one of the most remarkable
scientific dreamers of antiquity. To have substituted for the Greek Pantheon
of anthropomorphic deities the conception of a non-anthropomorphic
immaterial and ethereal entity, of all things in the world "the most rarefied
and the purest," is to have performed a feat which, considering the age and
the environment in which it was accomplished, staggers the imagination. As
a strictly scientific accomplishment the great thinker's conception of
primordial elements contained a germ of the truth which was to lie dormant
for 2200 years, but which then, as modified and vitalized by the genius of
Dalton, was to dominate the new chemical science of the nineteenth
century. If there are intimations that the primordial element of Anaxagoras
and of Dalton may turn out in the near future to be itself a compound, there
will still remain the yet finer particles of the nous of Anaxagoras to baffle
the most subtle analysis of which to-day's science gives us any pre-vision.
All in all, then, the work of Anaxagoras must stand as that of perhaps the
most far-seeing scientific imagination of pre-Socratic antiquity.
LEUCIPPUS AND DEMOCRITUS
But we must not leave this alluring field of speculation as to the nature of
matter without referring to another scientific guess, which soon followed
that of Anaxagoras and was destined to gain even wider fame, and which in
modern times has been somewhat unjustly held to eclipse the glory of the
other achievement. We mean, of course, the atomic theory of Leucippus and
Democritus. This theory reduced all matter to primordial elements, called
atoms (gr atoma) because they are by hypothesis incapable of further
division. These atoms, making up the entire material universe, are in this

theory conceived as qualitatively identical, differing from one another only
in size and perhaps in shape. The union of different-sized atoms in endless
combinations produces the diverse substances with which our senses make
us familiar.
Before we pass to a consideration of this alluring theory, and particularly
to a comparison of it with the theory of Anaxagoras, we must catch a
glimpse of the personality of the men to whom the theory owes its origin.
One of these, Leucippus, presents so uncertain a figure as to be almost
mythical. Indeed, it was long questioned whether such a man had actually
lived, or whether he were not really an invention of his alleged disciple,
Democritus. Latterday scholarship, however, accepts him as a real
personage, though knowing scarcely more of him than that he was the
author of the famous theory with which his name was associated. It is
suggested that he was a wanderer, like most philosophers of his time, and
that later in life he came to Abdera, in Thrace, and through this
circumstance became the teacher of Democritus. This fable answers as well
as another. What we really know is that Democritus himself, through whose
writings and teachings the atomic theory gained vogue, was born in Abdera,
about the year 460 B.C.—that is to say, just about the time when his great
precursor, Anaxagoras, was migrating to Athens. Democritus, like most
others of the early Greek thinkers, lives in tradition as a picturesque figure.
It is vaguely reported that he travelled for a time, perhaps in the East and in
Egypt, and that then he settled down to spend the remainder of his life in
Abdera. Whether or not he visited Athens in the course of his wanderings
we do not know. At Abdera he was revered as a sage, but his influence upon
the practical civilization of the time was not marked. He was pre-eminently
a dreamer and a writer. Like his confreres of the epoch, he entered all fields
of thought. He wrote voluminously, but, unfortunately, his writings have,
for the most part, perished. The fables and traditions of a later day asserted
that Democritus had voluntarily put out his own eyes that he might turn his
thoughts inward with more concentration. Doubtless this is fiction, yet, as
usual with such fictions, it contains a germ of truth; for we may well
suppose that the promulgator of the atomic theory was a man whose mind
was attracted by the subtleties of thought rather than by the tangibilities of
observation. Yet the term "laughing philosopher," which seems to have been
universally applied to Democritus, suggests a mind not altogether
withdrawn from the world of practicalities.

So much for Democritus the man. Let us return now to his theory of
atoms. This theory, it must be confessed, made no very great impression
upon his contemporaries. It found an expositor, a little later, in the
philosopher Epicurus, and later still the poet Lucretius gave it popular
expression. But it seemed scarcely more than the dream of a philosopher or
the vagary of a poet until the day when modern science began to penetrate
the mysteries of matter. When, finally, the researches of Dalton and his
followers had placed the atomic theory on a surer footing as the foundation
of modern chemistry, the ideas of the old laughing philosopher of Abdera,
which all along had been half derisively remembered, were recalled with a
new interest. Now it appeared that these ideas had curiously foreshadowed
nineteenth-century knowledge. It appeared that away back in the fifth
century B.C. a man had dreamed out a conception of the ultimate nature of
matter which had waited all these centuries for corroboration. And now the
historians of philosophy became more than anxious to do justice to the
memory of Democritus.
It is possible that this effort at poetical restitution has carried the
enthusiast too far. There is, indeed, a curious suggestiveness in the theory of
Democritus; there is philosophical allurement in his reduction of all matter
to a single element; it contains, it may be, not merely a germ of the science
of the nineteenth-century chemistry, but perhaps the germs also of the yet
undeveloped chemistry of the twentieth century. Yet we dare suggest that in
their enthusiasm for the atomic theory of Democritus the historians of our
generation have done something less than justice to that philosopher's
precursor, Anaxagoras. And one suspects that the mere accident of a name
has been instrumental in producing this result. Democritus called his
primordial element an atom; Anaxagoras, too, conceived a primordial
element, but he called it merely a seed or thing; he failed to christen it
distinctively. Modern science adopted the word atom and gave it universal
vogue. It owed a debt of gratitude to Democritus for supplying it the word,
but it somewhat overpaid the debt in too closely linking the new meaning of
the word with its old original one. For, let it be clearly understood, the
Daltonian atom is not precisely comparable with the atom of Democritus.
The atom, as Democritus conceived it, was monistic; all atoms, according
to this hypothesis, are of the same substance; one atom differs from another
merely in size and shape, but not at all in quality. But the Daltonian
hypothesis conceived, and nearly all the experimental efforts of the

nineteenth century seemed to prove, that there are numerous classes of
atoms, each differing in its very essence from the others.
As the case stands to-day the chemist deals with seventy-odd substances,
which he calls elements. Each one of these substances is, as he conceives it,
made up of elementary atoms having a unique personality, each differing in
quality from all the others. As far as experiment has thus far safely carried
us, the atom of gold is a primordial element which remains an atom of gold
and nothing else, no matter with what other atoms it is associated. So, too,
of the atom of silver, or zinc, or sodium—in short, of each and every one of
the seventy-odd elements. There are, indeed, as we shall see, experiments
that suggest the dissolution of the atom—that suggest, in short, that the
Daltonian atom is misnamed, being a structure that may, under certain
conditions, be broken asunder. But these experiments have, as yet, the
warrant rather of philosophy than of pure science, and to-day we demand
that the philosophy of science shall be the handmaid of experiment.
When experiment shall have demonstrated that the Daltonian atom is a
compound, and that in truth there is but a single true atom, which,
combining with its fellows perhaps in varying numbers and in different
special relations, produces the Daltonian atoms, then the philosophical
theory of monism will have the experimental warrant which to-day it lacks;
then we shall be a step nearer to the atom of Democritus in one direction, a
step farther away in the other. We shall be nearer, in that the conception of
Democritus was, in a sense, monistic; farther away, in that all the atoms of
Democritus, large and small alike, were considered as permanently fixed in
size. Democritus postulated all his atoms as of the same substance, differing
not at all in quality; yet he was obliged to conceive that the varying size of
the atoms gave to them varying functions which amounted to qualitative
differences. He might claim for his largest atom the same quality of
substance as for his smallest, but so long as he conceived that the large
atoms, when adjusted together to form a tangible substance, formed a
substance different in quality from the substance which the small atoms
would make up when similarly grouped, this concession amounts to the
predication of difference of quality between the atoms themselves. The
entire question reduces itself virtually to a quibble over the word quality, So
long as one atom conceived to be primordial and indivisible is conceded to
be of such a nature as necessarily to produce a different impression on our
senses, when grouped with its fellows, from the impression produced by

other atoms when similarly grouped, such primordial atoms do differ
among themselves in precisely the same way for all practical purposes as do
the primordial elements of Anaxagoras.
The monistic conception towards which twentieth-century chemistry
seems to be carrying us may perhaps show that all the so-called atoms are
compounded of a single element. All the true atoms making up that element
may then properly be said to have the same quality, but none the less will it
remain true that the combinations of that element that go to make up the
different Daltonian atoms differ from one another in quality in precisely the
same sense in which such tangible substances as gold, and oxygen, and
mercury, and diamonds differ from one another. In the last analysis of the
monistic philosophy, there is but one substance and one quality in the
universe. In the widest view of that philosophy, gold and oxygen and
mercury and diamonds are one substance, and, if you please, one quality.
But such refinements of analysis as this are for the transcendental
philosopher, and not for the scientist. Whatever the allurement of such
reasoning, we must for the purpose of science let words have a specific
meaning, nor must we let a mere word-jugglery blind us to the evidence of
facts. That was the rock on which Greek science foundered; it is the rock
which the modern helmsman sometimes finds it difficult to avoid. And if
we mistake not, this case of the atom of Democritus is precisely a case in
point. Because Democritus said that his atoms did not differ in quality, the
modern philosopher has seen in his theory the essentials of monism; has
discovered in it not merely a forecast of the chemistry of the nineteenth
century, but a forecast of the hypothetical chemistry of the future. And, on
the other hand, because Anaxagoras predicted a different quality for his
primordial elements, the philosopher of our day has discredited the
primordial element of Anaxagoras.
Yet if our analysis does not lead us astray, the theory of Democritus was
not truly monistic; his indestructible atoms, differing from one another in
size and shape, utterly incapable of being changed from the form which
they had maintained from the beginning, were in reality as truly and
primordially different as are the primordial elements of Anaxagoras. In
other words, the atom of Democritus is nothing less than the primordial
seed of Anaxagoras, a little more tangibly visualized and given a distinctive
name. Anaxagoras explicitly conceived his elements as invisibly small, as
infinite in number, and as made up of an indefinite number of kinds—one

for each distinctive substance in the world. But precisely the same
postulates are made of the atom of Democritus. These also are invisibly
small; these also are infinite in number; these also are made up of an
indefinite number of kinds, corresponding with the observed difference of
substances in the world. "Primitive seeds," or "atoms," were alike
conceived to be primordial, un-changeable, and indestructible. Wherein
then lies the difference? We answer, chiefly in a name; almost solely in the
fact that Anaxagoras did not attempt to postulate the physical properties of
the elements beyond stating that each has a distinctive personality, while
Democritus did attempt to postulate these properties. He, too, admitted that
each kind of element has its distinctive personality, and he attempted to
visualize and describe the characteristics of the personality.
Thus while Anaxagoras tells us nothing of his elements except that they
differ from one another, Democritus postulates a difference in size,
imagines some elements as heavier and some as lighter, and conceives even
that the elements may be provided with projecting hooks, with the aid of
which they link themselves one with another. No one to-day takes these
crude visualizings seriously as to their details. The sole element of truth
which these dreamings contain, as distinguishing them from the dreamings
of Anaxagoras, is in the conception that the various atoms differ in size and
weight. Here, indeed, is a vague fore-shadowing of that chemistry of form
which began to come into prominence towards the close of the nineteenth
century. To have forecast even dimly this newest phase of chemical
knowledge, across the abyss of centuries, is indeed a feat to put Democritus
in the front rank of thinkers. But this estimate should not blind us to the fact
that the pre-vision of Democritus was but a slight elaboration of a theory
which had its origin with another thinker. The association between
Anaxagoras and Democritus cannot be directly traced, but it is an
association which the historian of ideas should never for a moment forget.
If we are not to be misled by mere word-jugglery, we shall recognize the
founder of the atomic theory of matter in Anaxagoras; its expositors along
slightly different lines in Leucippus and Democritus; its re-discoverer of the
nineteenth century in Dalton. All in all, then, just as Anaxagoras preceded
Democritus in time, so must he take precedence over him also as an
inductive thinker, who carried the use of the scientific imagination to its
farthest reach.

An analysis of the theories of the two men leads to somewhat the same
conclusion that might be reached from a comparison of their lives.
Anaxagoras was a sceptical, experimental scientist, gifted also with the
prophetic imagination. He reasoned always from the particular to the
general, after the manner of true induction, and he scarcely took a step
beyond the confines of secure induction. True scientist that he was, he could
content himself with postulating different qualities for his elements, without
pretending to know how these qualities could be defined. His elements were
by hypothesis invisible, hence he would not attempt to visualize them.
Democritus, on the other hand, refused to recognize this barrier. Where he
could not know, he still did not hesitate to guess. Just as he conceived his
atom of a definite form with a definite structure, even so he conceived that
the atmosphere about him was full of invisible spirits; he accepted the
current superstitions of his time. Like the average Greeks of his day, he
even believed in such omens as those furnished by inspecting the entrails of
a fowl. These chance bits of biography are weather-vanes of the mind of
Democritus. They tend to substantiate our conviction that Democritus must
rank below Anaxagoras as a devotee of pure science. But, after all, such
comparisons and estimates as this are utterly futile. The essential fact for us
is that here, in the fifth century before our era, we find put forward the most
penetrating guess as to the constitution of matter that the history of ancient
thought has to present to us. In one direction, the avenue of progress is
barred; there will be no farther step that way till we come down the
centuries to the time of Dalton.
HIPPOCRATES AND GREEK MEDICINE
These studies of the constitution of matter have carried us to the limits of
the field of scientific imagination in antiquity; let us now turn sharply and
consider a department of science in which theory joins hands with
practicality. Let us witness the beginnings of scientific therapeutics.
Medicine among the early Greeks, before the time of Hippocrates, was a
crude mixture of religion, necromancy, and mysticism. Temples were
erected to the god of medicine, aesculapius, and sick persons made their
way, or were carried, to these temples, where they sought to gain the favor
of the god by suitable offerings, and learn the way to regain their health
through remedies or methods revealed to them in dreams by the god. When
the patient had been thus cured, he placed a tablet in the temple describing

his sickness, and telling by what method the god had cured him. He again
made suitable offerings at the temple, which were sometimes in the form of
gold or silver representations of the diseased organ—a gold or silver model
of a heart, hand, foot, etc.
Nevertheless, despite this belief in the supernatural, many drugs and
healing lotions were employed, and the Greek physicians possessed
considerable skill in dressing wounds and bandaging. But they did not
depend upon these surgical dressings alone, using with them certain
appropriate prayers and incantations, recited over the injured member at the
time of applying the dressings.
Even the very early Greeks had learned something of anatomy. The daily
contact with wounds and broken bones must of necessity lead to a crude
understanding of anatomy in general. The first Greek anatomist, however,
who is recognized as such, is said to have been Alcmaeon. He is said to
have made extensive dissections of the lower animals, and to have
described many hitherto unknown structures, such as the optic nerve and
the Eustachian canal—the small tube leading into the throat from the ear.
He is credited with many unique explanations of natural phenomena, such
as, for example, the explanation that "hearing is produced by the hollow
bone behind the ear; for all hollow things are sonorous." He was a
rationalist, and he taught that the brain is the organ of mind. The sources of
our information about his work, however, are unreliable.
Democedes, who lived in the sixth century B.C., is the first physician of
whom we have any trustworthy history. We learn from Herodotus that he
came from Croton to aegina, where, in recognition of his skill, he was
appointed medical officer of the city. From aegina he was called to Athens
at an increased salary, and later was in charge of medical affairs in several
other Greek cities. He was finally called to Samos by the tyrant Polycrates,
who reigned there from about 536 to 522 B.C. But on the death of
Polycrates, who was murdered by the Persians, Democedes became a slave.
His fame as a physician, however, had reached the ears of the Persian
monarch, and shortly after his capture he was permitted to show his skill
upon King Darius himself. The Persian monarch was suffering from a
sprained ankle, which his Egyptian surgeons had been unable to cure.
Democedes not only cured the injured member but used his influence in

saving the lives of his Egyptian rivals, who had been condemned to death
by the king.
At another time he showed his skill by curing the queen, who was
suffering from a chronic abscess of long standing. This so pleased the
monarch that he offered him as a reward anything he might desire, except
his liberty. But the costly gifts of Darius did not satisfy him so long as he
remained a slave; and determined to secure his freedom at any cost, he
volunteered to lead some Persian spies into his native country, promising to
use his influence in converting some of the leading men of his nation to the
Persian cause. Laden with the wealth that had been heaped upon him by
Darius, he set forth upon his mission, but upon reaching his native city of
Croton he threw off his mask, renounced his Persian mission, and became
once more a free Greek.
While the story of Democedes throws little light upon the medical
practices of the time, it shows that paid city medical officers existed in
Greece as early as the fifth and sixth centuries B.C. Even then there were
different "schools" of medicine, whose disciples disagreed radically in their
methods of treating diseases; and there were also specialists in certain
diseases, quacks, and charlatans. Some physicians depended entirely upon
external lotions for healing all disorders; others were "hydrotherapeutists"
or "bath-physicians"; while there were a host of physicians who
administered a great variety of herbs and drugs. There were also magicians
who pretended to heal by sorcery, and great numbers of bone-setters,
oculists, and dentists.
Many of the wealthy physicians had hospitals, or clinics, where patients
were operated upon and treated. They were not hospitals in our modern
understanding of the term, but were more like dispensaries, where patients
were treated temporarily, but were not allowed to remain for any length of
time. Certain communities established and supported these dispensaries for
the care of the poor.
But anything approaching a rational system of medicine was not
established, until Hippocrates of Cos, the "father of medicine," came upon
the scene. In an age that produced Phidias, Lysias, Herodotus, Sophocles,
and Pericles, it seems but natural that the medical art should find an
exponent who would rise above superstitious dogmas and lay the
foundation for a medical science. His rejection of the supernatural alone

stamps the greatness of his genius. But, besides this, he introduced more
detailed observation of diseases, and demonstrated the importance that
attaches to prognosis.
Hippocrates was born at Cos, about 460 B.C., but spent most of his life at
Larissa, in Thessaly. He was educated as a physician by his father, and
travelled extensively as an itinerant practitioner for several years. His
travels in different climates and among many different people undoubtedly
tended to sharpen his keen sense of observation. He was a practical
physician as well as a theorist, and, withal, a clear and concise writer. "Life
is short," he says, "opportunity fleeting, judgment difficult, treatment easy,
but treatment after thought is proper and profitable."
His knowledge of anatomy was necessarily very imperfect, and was
gained largely from his predecessors, to whom he gave full credit.
Dissections of the human body were forbidden him, and he was obliged to
confine his experimental researches to operations on the lower animals. His
knowledge of the structure and arrangement of the bones, however, was
fairly accurate, but the anatomy of the softer tissues, as he conceived it, was
a queer jumbling together of blood-vessels, muscles, and tendons. He does
refer to "nerves," to be sure, but apparently the structures referred to are the
tendons and ligaments, rather than the nerves themselves. He was better
acquainted with the principal organs in the cavities of the body, and knew,
for example, that the heart is divided into four cavities, two of which he
supposed to contain blood, and the other two air.
His most revolutionary step was his divorcing of the supernatural from
the natural, and establishing the fact that disease is due to natural causes
and should be treated accordingly. The effect of such an attitude can hardly
be over-estimated. The establishment of such a theory was naturally
followed by a close observation as to the course of diseases and the effects
of treatment. To facilitate this, he introduced the custom of writing down his
observations as he made them—the "clinical history" of the case. Such
clinical records are in use all over the world to-day, and their importance is
so obvious that it is almost incomprehensible that they should have fallen
into disuse shortly after the time of Hippocrates, and not brought into
general use again until almost two thousand years later.
But scarcely less important than his recognition of disease as a natural
phenomenon was the importance he attributed to prognosis. Prognosis, in

the sense of prophecy, was common before the time of Hippocrates. But
prognosis, as he practised it and as we understand it to-day, is prophecy
based on careful observation of the course of diseases—something more
than superstitious conjecture.
Although Hippocratic medicine rested on the belief in natural causes,
nevertheless, dogma and theory held an important place. The humoral
theory of disease was an all-important one, and so fully was this theory
accepted that it influenced the science of medicine all through succeeding
centuries. According to this celebrated theory there are four humors in the
body—blood, phlegm, yellow bile, and black bile. When these humors are
mixed in exact proportions they constitute health; but any deviations from
these proportions produce disease. In treating diseases the aim of the
physician was to discover which of these humors were out of proportion
and to restore them to their natural equilibrium. It was in the methods
employed in this restitution, rather than a disagreement about the humors
themselves, that resulted in the various "schools" of medicine.
In many ways the surgery of Hippocrates showed a better understanding
of the structure of the organs than of their functions. Some of the surgical
procedures as described by him are followed, with slight modifications, to-
day. Many of his methods were entirely lost sight of until modern times,
and one, the treatment of dislocation of the outer end of the collar-bone,
was not revived until some time in the eighteenth century.
Hippocrates, it seems, like modern physicians, sometimes suffered from
the ingratitude of his patients. "The physician visits a patient suffering from
fever or a wound, and prescribes for him," he says; "on the next day, if the
patient feels worse the blame is laid upon the physician; if, on the other
hand, he feels better, nature is extolled, and the physician reaps no praise."
The essence of this has been repeated in rhyme and prose by writers in
every age and country, but the "father of medicine" cautions physicians
against allowing it to influence their attitude towards their profession.

VIII. POST-SOCRATIC SCIENCE AT ATHENS
—PLATO, ARISTOTLE, AND
THEOPHRASTUS
Doubtless it has been noticed that our earlier scientists were as far
removed as possible from the limitations of specialism. In point of fact, in
this early day, knowledge had not been classified as it came to be later on.
The philosopher was, as his name implied, a lover of knowledge, and he did
not find it beyond the reach of his capacity to apply himself to all
departments of the field of human investigation. It is nothing strange to
discover that Anaximander and the Pythagoreans and Anaxagoras have
propounded theories regarding the structure of the cosmos, the origin and
development of animals and man, and the nature of matter itself.
Nowadays, so enormously involved has become the mass of mere facts
regarding each of these departments of knowledge that no one man has the
temerity to attempt to master them all. But it was different in those days of
beginnings. Then the methods of observation were still crude, and it was
quite the custom for a thinker of forceful personality to find an eager
following among disciples who never thought of putting his theories to the
test of experiment. The great lesson that true science in the last resort
depends upon observation and measurement, upon compass and balance,
had not yet been learned, though here and there a thinker like Anaxagoras
had gained an inkling of it.
For the moment, indeed, there in Attica, which was now, thanks to that
outburst of Periclean culture, the centre of the world's civilization, the trend
of thought was to take quite another direction. The very year which saw the
birth of Democritus at Abdera, and of Hippocrates, marked also the birth, at
Athens, of another remarkable man, whose influence it would scarcely be
possible to over-estimate. This man was Socrates. The main facts of his
history are familiar to every one. It will be recalled that Socrates spent his
entire life in Athens, mingling everywhere with the populace; haranguing,
so the tradition goes, every one who would listen; inculcating moral
lessons, and finally incurring the disapprobation of at least a voting

majority of his fellow-citizens. He gathered about him a company of
remarkable men with Plato at their head, but this could not save him from
the disapprobation of the multitudes, at whose hands he suffered death,
legally administered after a public trial. The facts at command as to certain
customs of the Greeks at this period make it possible to raise a question as
to whether the alleged "corruption of youth," with which Socrates was
charged, may not have had a different implication from what posterity has
preferred to ascribe to it. But this thought, almost shocking to the modern
mind and seeming altogether sacrilegious to most students of Greek
philosophy, need not here detain us; neither have we much concern in the
present connection with any part of the teaching of the martyred
philosopher. For the historian of metaphysics, Socrates marks an epoch, but
for the historian of science he is a much less consequential figure.
Similarly regarding Plato, the aristocratic Athenian who sat at the feet of
Socrates, and through whose writings the teachings of the master found
widest currency. Some students of philosophy find in Plato "the greatest
thinker and writer of all time."(1) The student of science must recognize in
him a thinker whose point of view was essentially non-scientific; one who
tended always to reason from the general to the particular rather than from
the particular to the general. Plato's writings covered almost the entire field
of thought, and his ideas were presented with such literary charm that
successive generations of readers turned to them with unflagging interest,
and gave them wide currency through copies that finally preserved them to
our own time. Thus we are not obliged in his case, as we are in the case of
every other Greek philosopher, to estimate his teachings largely from
hearsay evidence. Plato himself speaks to us directly. It is true, the literary
form which he always adopted, namely, the dialogue, does not give quite
the same certainty as to when he is expressing his own opinions that a more
direct narrative would have given; yet, in the main, there is little doubt as to
the tenor of his own opinions—except, indeed, such doubt as always
attaches to the philosophical reasoning of the abstract thinker.
What is chiefly significant from our present standpoint is that the great
ethical teacher had no significant message to give the world regarding the
physical sciences. He apparently had no sharply defined opinions as to the
mechanism of the universe; no clear conception as to the origin or
development of organic beings; no tangible ideas as to the problems of
physics; no favorite dreams as to the nature of matter. Virtually his back

was turned on this entire field of thought. He was under the sway of those
innate ideas which, as we have urged, were among the earliest inductions of
science. But he never for a moment suspected such an origin for these ideas.
He supposed his conceptions of being, his standards of ethics, to lie back of
all experience; for him they were the most fundamental and most
dependable of facts. He criticised Anaxagoras for having tended to deduce
general laws from observation. As we moderns see it, such criticism is the
highest possible praise. It is a criticism that marks the distinction between
the scientist who is also a philosopher and the philosopher who has but a
vague notion of physical science. Plato seemed, indeed, to realize the value
of scientific investigation; he referred to the astronomical studies of the
Egyptians and Chaldeans, and spoke hopefully of the results that might
accrue were such studies to be taken up by that Greek mind which, as he
justly conceived, had the power to vitalize and enrich all that it touched. But
he told here of what he would have others do, not of what he himself
thought of doing. His voice was prophetic, but it stimulated no worker of
his own time.
Plato himself had travelled widely. It is a familiar legend that he lived for
years in Egypt, endeavoring there to penetrate the mysteries of Egyptian
science. It is said even that the rudiments of geometry which he acquired
there influenced all his later teachings. But be that as it may, the historian of
science must recognize in the founder of the Academy a moral teacher and
metaphysical dreamer and sociologist, but not, in the modern acceptance of
the term, a scientist. Those wider phases of biological science which find
their expression in metaphysics, in ethics, in political economy, lie without
our present scope; and for the development of those subjects with which we
are more directly concerned, Plato, like his master, has a negative
significance.
ARISTOTLE (384-322 B.C.)
When we pass to that third great Athenian teacher, Aristotle, the case is
far different. Here was a man whose name was to be received as almost a
synonym for Greek science for more than a thousand years after his death.
All through the Middle Ages his writings were to be accepted as virtually
the last word regarding the problems of nature. We shall see that his
followers actually preferred his mandate to the testimony of their own
senses. We shall see, further, that modern science progressed somewhat in

proportion as it overthrew the Aristotelian dogmas. But the traditions of
seventeen or eighteen centuries are not easily set aside, and it is perhaps not
too much to say that the name of Aristotle stands, even in our own time, as
vaguely representative in the popular mind of all that was highest and best
in the science of antiquity. Yet, perhaps, it would not be going too far to
assert that something like a reversal of this judgment would be nearer the
truth. Aristotle did, indeed, bring together a great mass of facts regarding
animals in his work on natural history, which, being preserved, has been
deemed to entitle its author to be called the "father of zoology." But there is
no reason to suppose that any considerable portion of this work contained
matter that was novel, or recorded observations that were original with
Aristotle; and the classifications there outlined are at best but a vague
foreshadowing of the elaboration of the science. Such as it is, however, the
natural history stands to the credit of the Stagirite. He must be credited, too,
with a clear enunciation of one most important scientific doctrine—namely,
the doctrine of the spherical figure of the earth. We have already seen that
this theory originated with the Pythagorean philosophers out in Italy. We
have seen, too, that the doctrine had not made its way in Attica in the time
of Anaxagoras. But in the intervening century it had gained wide currency,
else so essentially conservative a thinker as Aristotle would scarcely have
accepted it. He did accept it, however, and gave the doctrine clearest and
most precise expression. Here are his words:(2)
"As to the figure of the earth it must necessarily be spherical.... If it were
not so, the eclipses of the moon would not have such sections as they have.
For in the configurations in the course of a month the deficient part takes all
different shapes; it is straight, and concave, and convex; but in eclipses it
always has the line of divisions convex; wherefore, since the moon is
eclipsed in consequence of the interposition of the earth, the periphery of
the earth must be the cause of this by having a spherical form. And again,
from the appearance of the stars it is clear, not only that the earth is round,
but that its size is not very large; for when we make a small removal to the
south or the north, the circle of the horizon becomes palpably different, so
that the stars overhead undergo a great change, and are not the same to
those that travel in the north and to the south. For some stars are seen in
Egypt or at Cyprus, but are not seen in the countries to the north of these;
and the stars that in the north are visible while they make a complete circuit,
there undergo a setting. So that from this it is manifest, not only that the

form of the earth is round, but also that it is a part of a not very large
sphere; for otherwise the difference would not be so obvious to persons
making so small a change of place. Wherefore we may judge that those
persons who connect the region in the neighborhood of the pillars of
Hercules with that towards India, and who assert that in this way the sea is
one, do not assert things very improbable. They confirm this conjecture
moreover by the elephants, which are said to be of the same species towards
each extreme; as if this circumstance was a consequence of the conjunction
of the extremes. The mathematicians who try to calculate the measure of the
circumference, make it amount to four hundred thousand stadia; whence we
collect that the earth is not only spherical, but is not large compared with
the magnitude of the other stars."
But in giving full meed of praise to Aristotle for the promulgation of this
doctrine of the sphericity of the earth, it must unfortunately be added that
the conservative philosopher paused without taking one other important
step. He could not accept, but, on the contrary, he expressly repudiated, the
doctrine of the earth's motion. We have seen that this idea also was a part of
the Pythagorean doctrine, and we shall have occasion to dwell more at
length on this point in a succeeding chapter. It has even been contended by
some critics that it was the adverse conviction of the Peripatetic philosopher
which, more than any other single influence, tended to retard the progress
of the true doctrine regarding the mechanism of the heavens. Aristotle
accepted the sphericity of the earth, and that doctrine became a
commonplace of scientific knowledge, and so continued throughout
classical antiquity. But Aristotle rejected the doctrine of the earth's motion,
and that doctrine, though promulgated actively by a few contemporaries and
immediate successors of the Stagirite, was then doomed to sink out of view
for more than a thousand years. If it be a correct assumption that the
influence of Aristotle was, in a large measure, responsible for this result,
then we shall perhaps not be far astray in assuming that the great founder of
the Peripatetic school was, on the whole, more instrumental in retarding the
progress of astronomical science that any other one man that ever lived.
The field of science in which Aristotle was pre-eminently a pathfinder is
zoology. His writings on natural history have largely been preserved, and
they constitute by far the most important contribution to the subject that has
come down to us from antiquity. They show us that Aristotle had gained
possession of the widest range of facts regarding the animal kingdom, and,

what is far more important, had attempted to classify these facts. In so
doing he became the founder of systematic zoology. Aristotle's
classification of the animal kingdom was known and studied throughout the
Middle Ages, and, in fact, remained in vogue until superseded by that of
Cuvier in the nineteenth century. It is not to be supposed that all the terms
of Aristotle's classification originated with him. Some of the divisions are
too patent to have escaped the observation of his predecessors. Thus, for
example, the distinction between birds and fishes as separate classes of
animals is so obvious that it must appeal to a child or to a savage. But the
efforts of Aristotle extended, as we shall see, to less patent generalizations.
At the very outset, his grand division of the animal kingdom into blood-
bearing and bloodless animals implies a very broad and philosophical
conception of the entire animal kingdom. The modern physiologist does not
accept the classification, inasmuch as it is now known that colorless fluids
perform the functions of blood for all the lower organisms. But the fact
remains that Aristotle's grand divisions correspond to the grand divisions of
the Lamarckian system—vertebrates and invertebrates—which every one
now accepts. Aristotle, as we have said, based his classification upon
observation of the blood; Lamarck was guided by a study of the skeleton.
The fact that such diverse points of view could direct the observer towards
the same result gives, inferentially, a suggestive lesson in what the modern
physiologist calls the homologies of parts of the organism.
Aristotle divides his so-called blood-bearing animals into five classes: (1)
Four-footed animals that bring forth their young alive; (2) birds; (3) egg-
laying four-footed animals (including what modern naturalists call reptiles
and amphibians); (4) whales and their allies; (5) fishes. This classification,
as will be observed, is not so very far afield from the modern divisions into
mammals, birds, reptiles, amphibians, and fishes. That Aristotle should have
recognized the fundamental distinction between fishes and the fish-like
whales, dolphins, and porpoises proves the far from superficial character of
his studies. Aristotle knew that these animals breathe by means of lungs and
that they produce living young. He recognized, therefore, their affinity with
his first class of animals, even if he did not, like the modern naturalist,
consider these affinities close enough to justify bringing the two types
together into a single class.
The bloodless animals were also divided by Aristotle into five classes—
namely: (1) Cephalopoda (the octopus, cuttle-fish, etc.); (2) weak-shelled

animals (crabs, etc.); (3) insects and their allies (including various forms,
such as spiders and centipedes, which the modern classifier prefers to place
by themselves); (4) hard-shelled animals (clams, oysters, snails, etc.); (5) a
conglomerate group of marine forms, including star-fish, sea-urchins, and
various anomalous forms that were regarded as linking the animal to the
vegetable worlds. This classification of the lower forms of animal life
continued in vogue until Cuvier substituted for it his famous grouping into
articulates, mollusks, and radiates; which grouping in turn was in part
superseded later in the nineteenth century.
What Aristotle did for the animal kingdom his pupil, Theophrastus, did in
some measure for the vegetable kingdom. Theophrastus, however, was
much less a classifier than his master, and his work on botany, called The
Natural History of Development, pays comparatively slight attention to
theoretical questions. It deals largely with such practicalities as the making
of charcoal, of pitch, and of resin, and the effects of various plants on the
animal organism when taken as foods or as medicines. In this regard the
work of Theophrastus, is more nearly akin to the natural history of the
famous Roman compiler, Pliny. It remained, however, throughout antiquity
as the most important work on its subject, and it entitles Theophrastus to be
called the "father of botany." Theophrastus deals also with the mineral
kingdom after much the same fashion, and here again his work is the most
notable that was produced in antiquity.

IX. GREEK SCIENCE OF THE
ALEXANDRIAN OR HELLENISTIC PERIOD
We are entering now upon the most important scientific epoch of
antiquity. When Aristotle and Theophrastus passed from the scene, Athens
ceased to be in any sense the scientific centre of the world. That city still
retained its reminiscent glory, and cannot be ignored in the history of
culture, but no great scientific leader was ever again to be born or to take up
his permanent abode within the confines of Greece proper. With almost
cataclysmic suddenness, a new intellectual centre appeared on the south
shore of the Mediterranean. This was the city of Alexandria, a city which
Alexander the Great had founded during his brief visit to Egypt, and which
became the capital of Ptolemy Soter when he chose Egypt as his portion of
the dismembered empire of the great Macedonian. Ptolemy had been with
his master in the East, and was with him in Babylonia when he died. He had
therefore come personally in contact with Babylonian civilization, and we
cannot doubt that this had a most important influence upon his life, and
through him upon the new civilization of the West. In point of culture,
Alexandria must be regarded as the successor of Babylon, scarcely less
directly than of Greece. Following the Babylonian model, Ptolemy erected
a great museum and began collecting a library. Before his death it was said
that he had collected no fewer than two hundred thousand manuscripts. He
had gathered also a company of great teachers and founded a school of
science which, as has just been said, made Alexandria the culture-centre of
the world.
Athens in the day of her prime had known nothing quite like this. Such
private citizens as Aristotle are known to have had libraries, but there were
no great public collections of books in Athens, or in any other part of the
Greek domain, until Ptolemy founded his famous library. As is well known,
such libraries had existed in Babylonia for thousands of years. The
character which the Ptolemaic epoch took on was no doubt due to
Babylonian influence, but quite as much to the personal experience of
Ptolemy himself as an explorer in the Far East. The marvellous conquering
journey of Alexander had enormously widened the horizon of the Greek

geographer, and stimulated the imagination of all ranks of the people, It was
but natural, then, that geography and its parent science astronomy should
occupy the attention of the best minds in this succeeding epoch. In point of
fact, such a company of star-gazers and earth-measurers came upon the
scene in this third century B.C. as had never before existed anywhere in the
world. The whole trend of the time was towards mechanics. It was as if the
greatest thinkers had squarely faced about from the attitude of the mystical
philosophers of the preceding century, and had set themselves the task of
solving all the mechanical riddles of the universe, They no longer troubled
themselves about problems of "being" and "becoming"; they gave but little
heed to metaphysical subtleties; they demanded that their thoughts should
be gauged by objective realities. Hence there arose a succession of great
geometers, and their conceptions were applied to the construction of new
mechanical contrivances on the one hand, and to the elaboration of theories
of sidereal mechanics on the other.
The wonderful company of men who performed the feats that are about
to be recorded did not all find their home in Alexandria, to be sure; but they
all came more or less under the Alexandrian influence. We shall see that
there are two other important centres; one out in Sicily, almost at the
confines of the Greek territory in the west; the other in Asia Minor, notably
on the island of Samos—the island which, it will be recalled, was at an
earlier day the birthplace of Pythagoras. But whereas in the previous
century colonists from the confines of the civilized world came to Athens,
now all eyes turned towards Alexandria, and so improved were the facilities
for communication that no doubt the discoveries of one coterie of workers
were known to all the others much more quickly than had ever been
possible before. We learn, for example, that the studies of Aristarchus of
Samos were definitely known to Archimedes of Syracuse, out in Sicily.
Indeed, as we shall see, it is through a chance reference preserved in one of
the writings of Archimedes that one of the most important speculations of
Aristarchus is made known to us. This illustrates sufficiently the
intercommunication through which the thought of the Alexandrian epoch
was brought into a single channel. We no longer, as in the day of the earlier
schools of Greek philosophy, have isolated groups of thinkers. The
scientific drama is now played out upon a single stage; and if we pass, as
we shall in the present chapter, from Alexandria to Syracuse and from

Syracuse to Samos, the shift of scenes does no violence to the dramatic
unities.
Notwithstanding the number of great workers who were not properly
Alexandrians, none the less the epoch is with propriety termed Alexandrian.
Not merely in the third century B.C., but throughout the lapse of at least
four succeeding centuries, the city of Alexander and the Ptolemies
continued to hold its place as the undisputed culture-centre of the world.
During that period Rome rose to its pinnacle of glory and began to decline,
without ever challenging the intellectual supremacy of the Egyptian city.
We shall see, in a later chapter, that the Alexandrian influences were passed
on to the Mohammedan conquerors, and every one is aware that when
Alexandria was finally overthrown its place was taken by another Greek
city, Byzantium or Constantinople. But that transfer did not occur until
Alexandria had enjoyed a longer period of supremacy as an intellectual
centre than had perhaps ever before been granted to any city, with the
possible exception of Babylon.
EUCLID (ABOUT 300 B.C.)
Our present concern is with that first wonderful development of scientific
activity which began under the first Ptolemy, and which presents, in the
course of the first century of Alexandrian influence, the most remarkable
coterie of scientific workers and thinkers that antiquity produced. The
earliest group of these new leaders in science had at its head a man whose
name has been a household word ever since. This was Euclid, the father of
systematic geometry. Tradition has preserved to us but little of the
personality of this remarkable teacher; but, on the other hand, his most
important work has come down to us in its entirety. The Elements of
Geometry, with which the name of Euclid is associated in the mind of every
school-boy, presented the chief propositions of its subject in so simple and
logical a form that the work remained a textbook everywhere for more than
two thousand years. Indeed it is only now beginning to be superseded. It is
not twenty years since English mathematicians could deplore the fact that,
despite certain rather obvious defects of the work of Euclid, no better
textbook than this was available. Euclid's work, of course, gives expression
to much knowledge that did not originate with him. We have already seen
that several important propositions of geometry had been developed by
Thales, and one by Pythagoras, and that the rudiments of the subject were at

least as old as Egyptian civilization. Precisely how much Euclid added
through his own investigations cannot be ascertained. It seems probable that
he was a diffuser of knowledge rather than an originator, but as a great
teacher his fame is secure. He is credited with an epigram which in itself
might insure him perpetuity of fame: "There is no royal road to geometry,"
was his answer to Ptolemy when that ruler had questioned whether the
Elements might not be simplified. Doubtless this, like most similar good
sayings, is apocryphal; but whoever invented it has made the world his
debtor.
HEROPHILUS AND ERASISTRATUS
The catholicity of Ptolemy's tastes led him, naturally enough, to cultivate
the biological no less than the physical sciences. In particular his influence
permitted an epochal advance in the field of medicine. Two anatomists
became famous through the investigations they were permitted to make
under the patronage of the enlightened ruler. These earliest of really
scientific investigators of the mechanism of the human body were named
Herophilus and Erasistratus. These two anatomists gained their knowledge
by the dissection of human bodies (theirs are the first records that we have
of such practices), and King Ptolemy himself is said to have been present at
some of these dissections. They were the first to discover that the nerve-
trunks have their origin in the brain and spinal cord, and they are credited
also with the discovery that these nerve-trunks are of two different kinds—
one to convey motor, and the other sensory impulses. They discovered,
described, and named the coverings of the brain. The name of Herophilus is
still applied by anatomists, in honor of the discoverer, to one of the sinuses
or large canals that convey the venous blood from the head. Herophilus also
noticed and described four cavities or ventricles in the brain, and reached
the conclusion that one of these ventricles was the seat of the soul—a belief
shared until comparatively recent times by many physiologists. He made
also a careful and fairly accurate study of the anatomy of the eye, a greatly
improved the old operation for cataract.
With the increased knowledge of anatomy came also corresponding
advances in surgery, and many experimental operations are said to have
been performed upon condemned criminals who were handed over to the
surgeons by the Ptolemies. While many modern writers have attempted to
discredit these assertions, it is not improbable that such operations were

performed. In an age when human life was held so cheap, and among a
people accustomed to torturing condemned prisoners for comparatively
slight offences, it is not unlikely that the surgeons were allowed to inflict
perhaps less painful tortures in the cause of science. Furthermore, we know
that condemned criminals were sometimes handed over to the medical
profession to be "operated upon and killed in whatever way they thought
best" even as late as the sixteenth century. Tertullian(1) probably
exaggerates, however, when he puts the number of such victims in
Alexandria at six hundred.
Had Herophilus and Erasistratus been as happy in their deductions as to
the functions of the organs as they were in their knowledge of anatomy, the
science of medicine would have been placed upon a very high plane even in
their time. Unfortunately, however, they not only drew erroneous inferences
as to the functions of the organs, but also disagreed radically as to what
functions certain organs performed, and how diseases should be treated,
even when agreeing perfectly on the subject of anatomy itself. Their
contribution to the knowledge of the scientific treatment of diseases holds
no such place, therefore, as their anatomical investigations.
Half a century after the time of Herophilus there appeared a Greek
physician, Heraclides, whose reputation in the use of drugs far surpasses
that of the anatomists of the Alexandrian school. His reputation has been
handed down through the centuries as that of a physician, rather than a
surgeon, although in his own time he was considered one of the great
surgeons of the period. Heraclides belonged to the "Empiric" school, which
rejected anatomy as useless, depending entirely on the use of drugs. He is
thought to have been the first physician to point out the value of opium in
certain painful diseases. His prescription of this drug for certain cases of
"sleeplessness, spasm, cholera, and colic," shows that his use of it was not
unlike that of the modern physician in certain cases; and his treatment of
fevers, by keeping the patient's head cool and facilitating the secretions of
the body, is still recognized as "good practice." He advocated a free use of
liquids in quenching the fever patient's thirst—a recognized therapeutic
measure to-day, but one that was widely condemned a century ago.
ARCHIMEDES OF SYRACUSE AND THE FOUNDATION OF
MECHANICS

We do not know just when Euclid died, but as he was at the height of his
fame in the time of Ptolemy I., whose reign ended in the year 285 B.C., it is
hardly probable that he was still living when a young man named
Archimedes came to Alexandria to study. Archimedes was born in the
Greek colony of Syracuse, on the island of Sicily, in the year 287 B.C.
When he visited Alexandria he probably found Apollonius of Perga, the
pupil of Euclid, at the head of the mathematical school there. Just how long
Archimedes remained at Alexandria is not known. When he had satisfied
his curiosity or completed his studies, he returned to Syracuse and spent his
life there, chiefly under the patronage of King Hiero, who seems fully to
have appreciated his abilities.
Archimedes was primarily a mathematician. Left to his own devices, he
would probably have devoted his entire time to the study of geometrical
problems. But King Hiero had discovered that his protege had wonderful
mechanical ingenuity, and he made good use of this discovery. Under stress
of the king's urgings, the philosopher was led to invent a great variety of
mechanical contrivances, some of them most curious ones. Antiquity
credited him with the invention of more than forty machines, and it is these,
rather than his purely mathematical discoveries, that gave his name popular
vogue both among his contemporaries and with posterity. Every one has
heard of the screw of Archimedes, through which the paradoxical effect was
produced of making water seem to flow up hill. The best idea of this
curious mechanism is obtained if one will take in hand an ordinary
corkscrew, and imagine this instrument to be changed into a hollow tube,
retaining precisely the same shape but increased to some feet in length and
to a proportionate diameter. If one will hold the corkscrew in a slanting
direction and turn it slowly to the right, supposing that the point dips up a
portion of water each time it revolves, one can in imagination follow the
flow of that portion of water from spiral to spiral, the water always running
downward, of course, yet paradoxically being lifted higher and higher
towards the base of the corkscrew, until finally it pours out (in the actual
Archimedes' tube) at the top. There is another form of the screw in which a
revolving spiral blade operates within a cylinder, but the principle is
precisely the same. With either form water may be lifted, by the mere
turning of the screw, to any desired height. The ingenious mechanism
excited the wonder of the contemporaries of Archimedes, as well it might.
More efficient devices have superseded it in modern times, but it still

excites the admiration of all who examine it, and its effects seem as
paradoxical as ever.
Some other of the mechanisms of Archimedes have been made known to
successive generations of readers through the pages of Polybius and
Plutarch. These are the devices through which Archimedes aided King
Hiero to ward off the attacks of the Roman general Marcellus, who in the
course of the second Punic war laid siege to Syracuse.
Plutarch, in his life of Marcellus, describes the Roman's attack and
Archimedes' defence in much detail. Incidentally he tells us also how
Archimedes came to make the devices that rendered the siege so famous:
"Marcellus himself, with threescore galleys of five rowers at every bank,
well armed and full of all sorts of artillery and fireworks, did assault by sea,
and rowed hard to the wall, having made a great engine and device of
battery, upon eight galleys chained together, to batter the wall: trusting in
the great multitude of his engines of battery, and to all such other necessary
provision as he had for wars, as also in his own reputation. But Archimedes
made light account of all his devices, as indeed they were nothing
comparable to the engines himself had invented. This inventive art to frame
instruments and engines (which are called mechanical, or organical, so
highly commended and esteemed of all sorts of people) was first set forth
by Architas, and by Eudoxus: partly to beautify a little the science of
geometry by this fineness, and partly to prove and confirm by material
examples and sensible instruments, certain geometrical conclusions, where
of a man cannot find out the conceivable demonstrations by enforced
reasons and proofs. As that conclusion which instructeth one to search out
two lines mean proportional, which cannot be proved by reason
demonstrative, and yet notwithstanding is a principle and an accepted
ground for many things which are contained in the art of portraiture. Both
of them have fashioned it to the workmanship of certain instruments, called
mesolabes or mesographs, which serve to find these mean lines
proportional, by drawing certain curve lines, and overthwart and oblique
sections. But after that Plato was offended with them, and maintained
against them, that they did utterly corrupt and disgrace, the worthiness and
excellence of geometry, making it to descend from things not
comprehensible and without body, unto things sensible and material, and to
bring it to a palpable substance, where the vile and base handiwork of man

is to be employed: since that time, I say, handicraft, or the art of engines,
came to be separated from geometry, and being long time despised by the
philosophers, it came to be one of the warlike arts.
"But Archimedes having told King Hiero, his kinsman and friend, that it
was possible to remove as great a weight as he would, with as little strength
as he listed to put to it: and boasting himself thus (as they report of him)
and trusting to the force of his reasons, wherewith he proved this
conclusion, that if there were another globe of earth, he was able to remove
this of ours, and pass it over to the other: King Hiero wondering to hear
him, required him to put his device in execution, and to make him see by
experience, some great or heavy weight removed, by little force. So
Archimedes caught hold with a book of one of the greatest carects, or hulks
of the king (that to draw it to the shore out of the water required a
marvellous number of people to go about it, and was hardly to be done so)
and put a great number of men more into her, than her ordinary burden: and
he himself sitting alone at his ease far off, without any straining at all,
drawing the end of an engine with many wheels and pulleys, fair and softly
with his hand, made it come as gently and smoothly to him, as it had floated
in the sea. The king wondering to see the sight, and knowing by proof the
greatness of his art; be prayed him to make him some engines, both to
assault and defend, in all manner of sieges and assaults. So Archimedes
made him many engines, but King Hiero never occupied any of them,
because he reigned the most part of his time in peace without any wars. But
this provision and munition of engines, served the Syracusan's turn
marvellously at that time: and not only the provision of the engines ready
made, but also the engineer and work-master himself, that had invented
them.
"Now the Syracusans, seeing themselves assaulted by the Romans, both
by sea and by land, were marvellously perplexed, and could not tell what to
say, they were so afraid: imagining it was impossible for them to withstand
so great an army. But when Archimedes fell to handling his engines, and to
set them at liberty, there flew in the air infinite kinds of shot, and
marvellous great stones, with an incredible noise and force on the sudden,
upon the footmen that came to assault the city by land, bearing down, and
tearing in pieces all those which came against them, or in what place soever
they lighted, no earthly body being able to resist the violence of so heavy a
weight: so that all their ranks were marvellously disordered. And as for the

galleys that gave assault by sea, some were sunk with long pieces of timber
like unto the yards of ships, whereto they fasten their sails, which were
suddenly blown over the walls with force of their engines into their galleys,
and so sunk them by their over great weight."
Polybius describes what was perhaps the most important of these
contrivances, which was, he tells us, "a band of iron, hanging by a chain
from the beak of a machine, which was used in the following manner. The
person who, like a pilot, guided the beak, having let fall the hand, and
catched hold of the prow of any vessel, drew down the opposite end of the
machine that was on the inside of the walls. And when the vessel was thus
raised erect upon its stem, the machine itself was held immovable; but, the
chain being suddenly loosened from the beak by the means of pulleys, some
of the vessels were thrown upon their sides, others turned with the bottom
upwards; and the greatest part, as the prows were plunged from a
considerable height into the sea, were filled with water, and all that were on
board thrown into tumult and disorder.
"Marcellus was in no small degree embarrassed," Polybius continues,
"when he found himself encountered in every attempt by such resistance.
He perceived that all his efforts were defeated with loss; and were even
derided by the enemy. But, amidst all the anxiety that he suffered, he could
not help jesting upon the inventions of Archimedes. This man, said he,
employs our ships as buckets to draw water: and boxing about our sackbuts,
as if they were unworthy to be associated with him, drives them from his
company with disgrace. Such was the success of the siege on the side of the
sea."
Subsequently, however, Marcellus took the city by strategy, and
Archimedes was killed, contrary, it is said, to the express orders of
Marcellus. "Syracuse being taken," says Plutarch, "nothing grieved
Marcellus more than the loss of Archimedes. Who, being in his study when
the city was taken, busily seeking out by himself the demonstration of some
geometrical proposition which he had drawn in figure, and so earnestly
occupied therein, as he neither saw nor heard any noise of enemies that ran
up and down the city, and much less knew it was taken: he wondered when
he saw a soldier by him, that bade him go with him to Marcellus.
Notwithstanding, he spake to the soldier, and bade him tarry until he had
done his conclusion, and brought it to demonstration: but the soldier being

angry with his answer, drew out his sword and killed him. Others say, that
the Roman soldier when he came, offered the sword's point to him, to kill
him: and that Archimedes when he saw him, prayed him to hold his hand a
little, that he might not leave the matter he looked for imperfect, without
demonstration. But the soldier making no reckoning of his speculation,
killed him presently. It is reported a third way also, saying that certain
soldiers met him in the streets going to Marcellus, carrying certain
mathematical instruments in a little pretty coffer, as dials for the sun,
spheres, and angles, wherewith they measure the greatness of the body of
the sun by view: and they supposing he had carried some gold or silver, or
other precious jewels in that little coffer, slew him for it. But it is most
certain that Marcellus was marvellously sorry for his death, and ever after
hated the villain that slew him, as a cursed and execrable person: and how
he had made also marvellous much afterwards of Archimedes' kinsmen for
his sake."
We are further indebted to Plutarch for a summary of the character and
influence of Archimedes, and for an interesting suggestion as to the
estimate which the great philosopher put upon the relative importance of his
own discoveries. "Notwithstanding Archimedes had such a great mind, and
was so profoundly learned, having hidden in him the only treasure and
secrets of geometrical inventions: as he would never set forth any book how
to make all these warlike engines, which won him at that time the fame and
glory, not of man's knowledge, but rather of divine wisdom. But he
esteeming all kind of handicraft and invention to make engines, and
generally all manner of sciences bringing common commodity by the use of
them, to be but vile, beggarly, and mercenary dross: employed his wit and
study only to write things, the beauty and subtlety whereof were not
mingled anything at all with necessity. For all that he hath written, are
geometrical propositions, which are without comparison of any other
writings whatsoever: because the subject where of they treat, doth appear
by demonstration, the maker gives them the grace and the greatness, and the
demonstration proving it so exquisitely, with wonderful reason and facility,
as it is not repugnable. For in all geometry are not to be found more
profound and difficult matters written, in more plain and simple terms, and
by more easy principles, than those which he hath invented. Now some do
impute this, to the sharpness of his wit and understanding, which was a
natural gift in him: others do refer it to the extreme pains he took, which

made these things come so easily from him, that they seemed as if they had
been no trouble to him at all. For no man living of himself can devise the
demonstration of his propositions, what pains soever he take to seek it: and
yet straight so soon as he cometh to declare and open it, every man then
imagineth with himself he could have found it out well enough, he can then
so plainly make demonstration of the thing he meaneth to show. And
therefore that methinks is likely to be true, which they write of him: that he
was so ravished and drunk with the sweet enticements of this siren, which
as it were lay continually with him, as he forgot his meat and drink, and was
careless otherwise of himself, that oftentimes his servants got him against
his will to the baths to wash and anoint him: and yet being there, he would
ever be drawing out of the geometrical figures, even in the very imbers of
the chimney. And while they were anointing of him with oils and sweet
savours, with his finger he did draw lines upon his naked body: so far was
he taken from himself, and brought into an ecstasy or trance, with the
delight he had in the study of geometry, and truly ravished with the love of
the Muses. But amongst many notable things he devised, it appeareth, that
he most esteemed the demonstration of the proportion between the cylinder
(to wit, the round column) and the sphere or globe contained in the same:
for he prayed his kinsmen and friends, that after his death they would put a
cylinder upon his tomb, containing a massy sphere, with an inscription of
the proportion, whereof the continent exceedeth the thing contained."(2)
It should be observed that neither Polybius nor Plutarch mentions the use
of burning-glasses in connection with the siege of Syracuse, nor indeed are
these referred to by any other ancient writer of authority. Nevertheless, a
story gained credence down to a late day to the effect that Archimedes had
set fire to the fleet of the enemy with the aid of concave mirrors. An
experiment was made by Sir Isaac Newton to show the possibility of a
phenomenon so well in accord with the genius of Archimedes, but the
silence of all the early authorities makes it more than doubtful whether any
such expedient was really adopted.
It will be observed that the chief principle involved in all these
mechanisms was a capacity to transmit great power through levers and
pulleys, and this brings us to the most important field of the Syracusan
philosopher's activity. It was as a student of the lever and the pulley that
Archimedes was led to some of his greatest mechanical discoveries. He is
even credited with being the discoverer of the compound pulley. More

likely he was its developer only, since the principle of the pulley was
known to the old Babylonians, as their sculptures testify. But there is no
reason to doubt the general outlines of the story that Archimedes astounded
King Hiero by proving that, with the aid of multiple pulleys, the strength of
one man could suffice to drag the largest ship from its moorings.
The property of the lever, from its fundamental principle, was studied by
him, beginning with the self-evident fact that "equal bodies at the ends of
the equal arms of a rod, supported on its middle point, will balance each
other"; or, what amounts to the same thing stated in another way, a regular
cylinder of uniform matter will balance at its middle point. From this
starting-point he elaborated the subject on such clear and satisfactory
principles that they stand to-day practically unchanged and with few
additions. From all his studies and experiments he finally formulated the
principle that "bodies will be in equilibrio when their distance from the
fulcrum or point of support is inversely as their weight." He is credited with
having summed up his estimate of the capabilities of the lever with the
well-known expression, "Give me a fulcrum on which to rest or a place on
which to stand, and I will move the earth."
But perhaps the feat of all others that most appealed to the imagination of
his contemporaries, and possibly also the one that had the greatest bearing
upon the position of Archimedes as a scientific discoverer, was the one
made familiar through the tale of the crown of Hiero. This crown, so the
story goes, was supposed to be made of solid gold, but King Hiero for some
reason suspected the honesty of the jeweller, and desired to know if
Archimedes could devise a way of testing the question without injuring the
crown. Greek imagination seldom spoiled a story in the telling, and in this
case the tale was allowed to take on the most picturesque of phases. The
philosopher, we are assured, pondered the problem for a long time without
succeeding, but one day as he stepped into a bath, his attention was
attracted by the overflow of water. A new train of ideas was started in his
ever-receptive brain. Wild with enthusiasm he sprang from the bath, and,
forgetting his robe, dashed along the streets of Syracuse, shouting: "Eureka!
Eureka!" (I have found it!) The thought that had come into his mind was
this: That any heavy substance must have a bulk proportionate to its weight;
that gold and silver differ in weight, bulk for bulk, and that the way to test
the bulk of such an irregular object as a crown was to immerse it in water.
The experiment was made. A lump of pure gold of the weight of the crown

was immersed in a certain receptacle filled with water, and the overflow
noted. Then a lump of pure silver of the same weight was similarly
immersed; lastly the crown itself was immersed, and of course—for the
story must not lack its dramatic sequel—was found bulkier than its weight
of pure gold. Thus the genius that could balk warriors and armies could also
foil the wiles of the silversmith.
Whatever the truth of this picturesque narrative, the fact remains that
some, such experiments as these must have paved the way for perhaps the
greatest of all the studies of Archimedes—those that relate to the buoyancy
of water. Leaving the field of fable, we must now examine these with some
precision. Fortunately, the writings of Archimedes himself are still extant, in
which the results of his remarkable experiments are related, so we may
present the results in the words of the discoverer.
Here they are: "First: The surface of every coherent liquid in a state of
rest is spherical, and the centre of the sphere coincides with the centre of the
earth. Second: A solid body which, bulk for bulk, is of the same weight as a
liquid, if immersed in the liquid will sink so that the surface of the body is
even with the surface of the liquid, but will not sink deeper. Third: Any
solid body which is lighter, bulk for bulk, than a liquid, if placed in the
liquid will sink so deep as to displace the mass of liquid equal in weight to
another body. Fourth: If a body which is lighter than a liquid is forcibly
immersed in the liquid, it will be pressed upward with a force
corresponding to the weight of a like volume of water, less the weight of the
body itself. Fifth: Solid bodies which, bulk for bulk, are heavier than a
liquid, when immersed in the liquid sink to the bottom, but become in the
liquid as much lighter as the weight of the displaced water itself differs
from the weight of the solid." These propositions are not difficult to
demonstrate, once they are conceived, but their discovery, combined with
the discovery of the laws of statics already referred to, may justly be
considered as proving Archimedes the most inventive experimenter of
antiquity.
Curiously enough, the discovery which Archimedes himself is said to
have considered the most important of all his innovations is one that seems
much less striking. It is the answer to the question, What is the relation in
bulk between a sphere and its circumscribing cylinder? Archimedes finds
that the ratio is simply two to three. We are not informed as to how he

reached his conclusion, but an obvious method would be to immerse a ball
in a cylindrical cup. The experiment is one which any one can make for
himself, with approximate accuracy, with the aid of a tumbler and a solid
rubber ball or a billiard-ball of just the right size. Another geometrical
problem which Archimedes solved was the problem as to the size of a
triangle which has equal area with a circle; the answer being, a triangle
having for its base the circumference of the circle and for its altitude the
radius. Archimedes solved also the problem of the relation of the diameter
of the circle to its circumference; his answer being a close approximation to
the familiar 3.1416, which every tyro in geometry will recall as the
equivalent of pi.
Numerous other of the studies of Archimedes having reference to conic
sections, properties of curves and spirals, and the like, are too technical to
be detailed here. The extent of his mathematical knowledge, however, is
suggested by the fact that he computed in great detail the number of grains
of sand that would be required to cover the sphere of the sun's orbit, making
certain hypothetical assumptions as to the size of the earth and the distance
of the sun for the purposes of argument. Mathematicians find his
computation peculiarly interesting because it evidences a crude conception
of the idea of logarithms. From our present stand-point, the paper in which
this calculation is contained has considerable interest because of its
assumptions as to celestial mechanics. Thus Archimedes starts out with the
preliminary assumption that the circumference of the earth is less than three
million stadia. It must be understood that this assumption is purely for the
sake of argument. Archimedes expressly states that he takes this number
because it is "ten times as large as the earth has been supposed to be by
certain investigators." Here, perhaps, the reference is to Eratosthenes,
whose measurement of the earth we shall have occasion to revert to in a
moment. Continuing, Archimedes asserts that the sun is larger than the
earth, and the earth larger than the moon. In this assumption, he says, he is
following the opinion of the majority of astronomers. In the third place,
Archimedes assumes that the diameter of the sun is not more than thirty
times greater than that of the moon. Here he is probably basing his
argument upon another set of measurements of Aristarchus, to which, also,
we shall presently refer more at length. In reality, his assumption is very far
from the truth, since the actual diameter of the sun, as we now know, is
something like four hundred times that of the moon. Fourth, the

circumference of the sun is greater than one side of the thousand-faced
figure inscribed in its orbit. The measurement, it is expressly stated, is
based on the measurements of Aristarchus, who makes the diameter of the
sun 1/170 of its orbit. Archimedes adds, however, that he himself has
measured the angle and that it appears to him to be less than 1/164, and
greater than 1/200 part of the orbit. That is to say, reduced to modern
terminology, he places the limit of the sun's apparent size between thirty-
three minutes and twenty-seven minutes of arc. As the real diameter is
thirty-two minutes, this calculation is surprisingly exact, considering the
implements then at command. But the honor of first making it must be
given to Aristarchus and not to Archimedes.
We need not follow Archimedes to the limits of his incomprehensible
numbers of sand-grains. The calculation is chiefly remarkable because it
was made before the introduction of the so-called Arabic numerals had
simplified mathematical calculations. It will be recalled that the Greeks
used letters for numerals, and, having no cipher, they soon found
themselves in difficulties when large numbers were involved. The Roman
system of numerals simplified the matter somewhat, but the beautiful
simplicity of the decimal system did not come into vogue until the Middle
Ages, as we shall see. Notwithstanding the difficulties, however,
Archimedes followed out his calculations to the piling up of bewildering
numbers, which the modern mathematician finds to be the consistent
outcome of the problem he had set himself.
But it remains to notice the most interesting feature of this document in
which the calculation of the sand-grains is contained. "It was known to me,"
says Archimedes, "that most astronomers understand by the expression
'world' (universe) a ball of which the centre is the middle point of the earth,
and of which the radius is a straight line between the centre of the earth and
the sun." Archimedes himself appears to accept this opinion of the majority,
—it at least serves as well as the contrary hypothesis for the purpose of his
calculation,—but he goes on to say: "Aristarchus of Samos, in his writing
against the astronomers, seeks to establish the fact that the world is really
very different from this. He holds the opinion that the fixed stars and the
sun are immovable and that the earth revolves in a circular line about the
sun, the sun being at the centre of this circle." This remarkable bit of
testimony establishes beyond question the position of Aristarchus of Samos
as the Copernicus of antiquity. We must make further inquiry as to the

teachings of the man who had gained such a remarkable insight into the true
system of the heavens.
ARISTARCHUS OF SAMOS, THE COPERNICUS OF ANTIQUITY
It appears that Aristarchus was a contemporary of Archimedes, but the
exact dates of his life are not known. He was actively engaged in making
astronomical observations in Samos somewhat before the middle of the
third century B.C.; in other words, just at the time when the activities of the
Alexandrian school were at their height. Hipparchus, at a later day, was
enabled to compare his own observations with those made by Aristarchus,
and, as we have just seen, his work was well known to so distant a
contemporary as Archimedes. Yet the facts of his life are almost a blank for
us, and of his writings only a single one has been preserved. That one,
however, is a most important and interesting paper on the measurements of
the sun and the moon. Unfortunately, this paper gives us no direct clew as
to the opinions of Aristarchus concerning the relative positions of the earth
and sun. But the testimony of Archimedes as to this is unequivocal, and this
testimony is supported by other rumors in themselves less authoritative.
In contemplating this astronomer of Samos, then, we are in the presence
of a man who had solved in its essentials the problem of the mechanism of
the solar system. It appears from the words of Archimedes that Aristarchus;
had propounded his theory in explicit writings. Unquestionably, then, he
held to it as a positive doctrine, not as a mere vague guess. We shall show,
in a moment, on what grounds he based his opinion. Had his teaching found
vogue, the story of science would be very different from what it is. We
should then have no tale to tell of a Copernicus coming upon the scene fully
seventeen hundred years later with the revolutionary doctrine that our world
is not the centre of the universe. We should not have to tell of the
persecution of a Bruno or of a Galileo for teaching this doctrine in the
seventeenth century of an era which did not begin till two hundred years
after the death of Aristarchus. But, as we know, the teaching of the
astronomer of Samos did not win its way. The old conservative geocentric
doctrine, seemingly so much more in accordance with the every-day
observations of mankind, supported by the majority of astronomers with the
Peripatetic philosophers at their head, held its place. It found fresh
supporters presently among the later Alexandrians, and so fully eclipsed the
heliocentric view that we should scarcely know that view had even found

an advocate were it not for here and there such a chance record as the
phrases we have just quoted from Archimedes. Yet, as we now see, the
heliocentric doctrine, which we know to be true, had been thought out and
advocated as the correct theory of celestial mechanics by at least one
worker of the third century B.C. Such an idea, we may be sure, did not
spring into the mind of its originator except as the culmination of a long
series of observations and inferences. The precise character of the evolution
we perhaps cannot trace, but its broader outlines are open to our
observation, and we may not leave so important a topic without at least
briefly noting them.
Fully to understand the theory of Aristarchus, we must go back a century
or two and recall that as long ago as the time of that other great native of
Samos, Pythagoras, the conception had been reached that the earth is in
motion. We saw, in dealing with Pythagoras, that we could not be sure as to
precisely what he himself taught, but there is no question that the idea of the
world's motion became from an early day a so-called Pythagorean doctrine.
While all the other philosophers, so far as we know, still believed that the
world was flat, the Pythagoreans out in Italy taught that the world is a
sphere and that the apparent motions of the heavenly bodies are really due
to the actual motion of the earth itself. They did not, however, vault to the
conclusion that this true motion of the earth takes place in the form of a
circuit about the sun. Instead of that, they conceived the central body of the
universe to be a great fire, invisible from the earth, because the inhabited
side of the terrestrial ball was turned away from it. The sun, it was held, is
but a great mirror, which reflects the light from the central fire. Sun and
earth alike revolve about this great fire, each in its own orbit. Between the
earth and the central fire there was, curiously enough, supposed to be an
invisible earthlike body which was given the name of Anticthon, or counter-
earth. This body, itself revolving about the central fire, was supposed to
shut off the central light now and again from the sun or from the moon, and
thus to account for certain eclipses for which the shadow of the earth did
not seem responsible. It was, perhaps, largely to account for such eclipses
that the counter-earth was invented. But it is supposed that there was
another reason. The Pythagoreans held that there is a peculiar sacredness in
the number ten. Just as the Babylonians of the early day and the Hegelian
philosophers of a more recent epoch saw a sacred connection between the
number seven and the number of planetary bodies, so the Pythagoreans

thought that the universe must be arranged in accordance with the number
ten. Their count of the heavenly bodies, including the sphere of the fixed
stars, seemed to show nine, and the counter-earth supplied the missing
body.
The precise genesis and development of this idea cannot now be
followed, but that it was prevalent about the fifth century B.C. as a
Pythagorean doctrine cannot be questioned. Anaxagoras also is said to have
taken account of the hypothetical counter-earth in his explanation of
eclipses; though, as we have seen, he probably did not accept that part of
the doctrine which held the earth to be a sphere. The names of Philolaus and
Heraclides have been linked with certain of these Pythagorean doctrines.
Eudoxus, too, who, like the others, lived in Asia Minor in the fourth century
B.C., was held to have made special studies of the heavenly spheres and
perhaps to have taught that the earth moves. So, too, Nicetas must be named
among those whom rumor credited with having taught that the world is in
motion. In a word, the evidence, so far as we can garner it from the
remaining fragments, tends to show that all along, from the time of the early
Pythagoreans, there had been an undercurrent of opinion in the
philosophical world which questioned the fixity of the earth; and it would
seem that the school of thinkers who tended to accept the revolutionary
view centred in Asia Minor, not far from the early home of the founder of
the Pythagorean doctrines. It was not strange, then, that the man who was
finally to carry these new opinions to their logical conclusion should hail
from Samos.
But what was the support which observation could give to this new,
strange conception that the heavenly bodies do not in reality move as they
seem to move, but that their apparent motion is due to the actual revolution
of the earth? It is extremely difficult for any one nowadays to put himself in
a mental position to answer this question. We are so accustomed to conceive
the solar system as we know it to be, that we are wont to forget how very
different it is from what it seems. Yet one needs but to glance up at the sky,
and then to glance about one at the solid earth, to grant, on a moment's
reflection, that the geocentric idea is of all others the most natural; and that
to conceive the sun as the actual Centre of the solar system is an idea which
must look for support to some other evidence than that which ordinary
observation can give. Such was the view of most of the ancient
philosophers, and such continued to be the opinion of the majority of

mankind long after the time of Copernicus. We must not forget that even so
great an observing astronomer as Tycho Brahe, so late as the seventeenth
century, declined to accept the heliocentric theory, though admitting that all
the planets except the earth revolve about the sun. We shall see that before
the Alexandrian school lost its influence a geocentric scheme had been
evolved which fully explained all the apparent motions of the heavenly
bodies. All this, then, makes us but wonder the more that the genius of an
Aristarchus could give precedence to scientific induction as against the
seemingly clear evidence of the senses.
What, then, was the line of scientific induction that led Aristarchus to this
wonderful goal? Fortunately, we are able to answer that query, at least in
part. Aristarchus gained his evidence through some wonderful
measurements. First, he measured the disks of the sun and the moon. This,
of course, could in itself give him no clew to the distance of these bodies,
and therefore no clew as to their relative size; but in attempting to obtain
such a clew he hit upon a wonderful yet altogether simple experiment. It
occurred to him that when the moon is precisely dichotomized—that is to
say, precisely at the half-the line of vision from the earth to the moon must
be precisely at right angles with the line of light passing from the sun to the
moon. At this moment, then, the imaginary lines joining the sun, the moon,
and the earth, make a right angle triangle. But the properties of the right-
angle triangle had long been studied and were well under stood. One acute
angle of such a triangle determines the figure of the triangle itself. We have
already seen that Thales, the very earliest of the Greek philosophers,
measured the distance of a ship at sea by the application of this principle.
Now Aristarchus sights the sun in place of Thales' ship, and, sighting the
moon at the same time, measures the angle and establishes the shape of his
right-angle triangle. This does not tell him the distance of the sun, to be
sure, for he does not know the length of his base-line—that is to say, of the
line between the moon and the earth. But it does establish the relation of
that base-line to the other lines of the triangle; in other words, it tells him
the distance of the sun in terms of the moon's distance. As Aristarchus
strikes the angle, it shows that the sun is eighteen times as distant as the
moon. Now, by comparing the apparent size of the sun with the apparent
size of the moon—which, as we have seen, Aristarchus has already
measured—he is able to tell us that, the sun is "more than 5832 times, and
less than 8000" times larger than the moon; though his measurements, taken

by themselves, give no clew to the actual bulk of either body. These
conclusions, be it understood, are absolutely valid inferences—nay,
demonstrations—from the measurements involved, provided only that these
measurements have been correct. Unfortunately, the angle of the triangle we
have just seen measured is exceedingly difficult to determine with accuracy,
while at the same time, as a moment's reflection will show, it is so large an
angle that a very slight deviation from the truth will greatly affect the
distance at which its line joins the other side of the triangle. Then again, it is
virtually impossible to tell the precise moment when the moon is at half, as
the line it gives is not so sharp that we can fix it with absolute accuracy.
There is, moreover, another element of error due to the refraction of light by
the earth's atmosphere. The experiment was probably made when the sun
was near the horizon, at which time, as we now know, but as Aristarchus
probably did not suspect, the apparent displacement of the sun's position is
considerable; and this displacement, it will be observed, is in the direction
to lessen the angle in question.
In point of fact, Aristarchus estimated the angle at eighty-seven degrees.
Had his instrument been more precise, and had he been able to take account
of all the elements of error, he would have found it eighty-seven degrees
and fifty-two minutes. The difference of measurement seems slight; but it
sufficed to make the computations differ absurdly from the truth. The sun is
really not merely eighteen times but more than two hundred times the
distance of the moon, as Wendelein discovered on repeating the experiment
of Aristarchus about two thousand years later. Yet this discrepancy does not
in the least take away from the validity of the method which Aristarchus
employed. Moreover, his conclusion, stated in general terms, was perfectly
correct: the sun is many times more distant than the moon and vastly larger
than that body. Granted, then, that the moon is, as Aristarchus correctly
believed, considerably less in size than the earth, the sun must be
enormously larger than the earth; and this is the vital inference which, more
than any other, must have seemed to Aristarchus to confirm the suspicion
that the sun and not the earth is the centre of the planetary system. It
seemed to him inherently improbable that an enormously large body like
the sun should revolve about a small one such as the earth. And again, it
seemed inconceivable that a body so distant as the sun should whirl through
space so rapidly as to make the circuit of its orbit in twenty-four hours. But,
on the other hand, that a small body like the earth should revolve about the

gigantic sun seemed inherently probable. This proposition granted, the
rotation of the earth on its axis follows as a necessary consequence in
explanation of the seeming motion of the stars. Here, then, was the
heliocentric doctrine reduced to a virtual demonstration by Aristarchus of
Samos, somewhere about the middle of the third century B.C.
It must be understood that in following out the steps of reasoning by
which we suppose Aristarchus to have reached so remarkable a conclusion,
we have to some extent guessed at the processes of thought-development;
for no line of explication written by the astronomer himself on this
particular point has come down to us. There does exist, however, as we
have already stated, a very remarkable treatise by Aristarchus on the Size
and Distance of the Sun and the Moon, which so clearly suggests the
methods of reasoning of the great astronomer, and so explicitly cites the
results of his measurements, that we cannot well pass it by without quoting
from it at some length. It is certainly one of the most remarkable scientific
documents of antiquity. As already noted, the heliocentric doctrine is not
expressly stated here. It seems to be tacitly implied throughout, but it is not
a necessary consequence of any of the propositions expressly stated. These
propositions have to do with certain observations and measurements and
what Aristarchus believes to be inevitable deductions from them, and he
perhaps did not wish to have these deductions challenged through
associating them with a theory which his contemporaries did not accept. In
a word, the paper of Aristarchus is a rigidly scientific document unvitiated
by association with any theorizings that are not directly germane to its
central theme. The treatise opens with certain hypotheses as follows:
"First. The moon receives its light from the sun.
"Second. The earth may be considered as a point and as the centre of the
orbit of the moon.
"Third. When the moon appears to us dichotomized it offers to our view a
great circle (or actual meridian) of its circumference which divides the
illuminated part from the dark part.
"Fourth. When the moon appears dichotomized its distance from the sun
is less than a quarter of the circumference (of its orbit) by a thirtieth part of
that quarter."
That is to say, in modern terminology, the moon at this time lacks three
degrees (one thirtieth of ninety degrees) of being at right angles with the

line of the sun as viewed from the earth; or, stated otherwise, the angular
distance of the moon from the sun as viewed from the earth is at this time
eighty-seven degrees—this being, as we have already observed, the
fundamental measurement upon which so much depends. We may fairly
suppose that some previous paper of Aristarchus's has detailed the
measurement which here is taken for granted, yet which of course could
depend solely on observation.
"Fifth. The diameter of the shadow (cast by the earth at the point where
the moon's orbit cuts that shadow when the moon is eclipsed) is double the
diameter of the moon."
Here again a knowledge of previously established measurements is taken
for granted; but, indeed, this is the case throughout the treatise.
"Sixth. The arc subtended in the sky by the moon is a fifteenth part of a
sign" of the zodiac; that is to say, since there are twenty-four, signs in the
zodiac, one-fifteenth of one twenty-fourth, or in modern terminology, one
degree of arc. This is Aristarchus's measurement of the moon to which we
have already referred when speaking of the measurements of Archimedes.
"If we admit these six hypotheses," Aristarchus continues, "it follows that
the sun is more than eighteen times more distant from the earth than is the
moon, and that it is less than twenty times more distant, and that the
diameter of the sun bears a corresponding relation to the diameter of the
moon; which is proved by the position of the moon when dichotomized. But
the ratio of the diameter of the sun to that of the earth is greater than
nineteen to three and less than forty-three to six. This is demonstrated by
the relation of the distances, by the position (of the moon) in relation to the
earth's shadow, and by the fact that the arc subtended by the moon is a
fifteenth part of a sign."
Aristarchus follows with nineteen propositions intended to elucidate his
hypotheses and to demonstrate his various contentions. These show a
singularly clear grasp of geometrical problems and an altogether correct
conception of the general relations as to size and position of the earth, the
moon, and the sun. His reasoning has to do largely with the shadow cast by
the earth and by the moon, and it presupposes a considerable knowledge of
the phenomena of eclipses. His first proposition is that "two equal spheres
may always be circumscribed in a cylinder; two unequal spheres in a cone
of which the apex is found on the side of the smaller sphere; and a straight

line joining the centres of these spheres is perpendicular to each of the two
circles made by the contact of the surface of the cylinder or of the cone with
the spheres."
It will be observed that Aristarchus has in mind here the moon, the earth,
and the sun as spheres to be circumscribed within a cone, which cone is
made tangible and measurable by the shadows cast by the non-luminous
bodies; since, continuing, he clearly states in proposition nine, that "when
the sun is totally eclipsed, an observer on the earth's surface is at an apex of
a cone comprising the moon and the sun." Various propositions deal with
other relations of the shadows which need not detain us since they are not
fundamentally important, and we may pass to the final conclusions of
Aristarchus, as reached in his propositions ten to nineteen.
Now, since (proposition ten) "the diameter of the sun is more than
eighteen times and less than twenty times greater than that of the moon," it
follows (proposition eleven) "that the bulk of the sun is to that of the moon
in ratio, greater than 5832 to 1, and less than 8000 to 1."
"Proposition sixteen. The diameter of the sun is to the diameter of the
earth in greater proportion than nineteen to three, and less than forty-three
to six.
"Proposition seventeen. The bulk of the sun is to that of the earth in
greater proportion than 6859 to 27, and less than 79,507 to 216.
"Proposition eighteen. The diameter of the earth is to the diameter of the
moon in greater proportion than 108 to 43 and less than 60 to 19.
"Proposition nineteen. The bulk of the earth is to that of the moon in
greater proportion than 1,259,712 to 79,507 and less than 20,000 to 6859."
Such then are the more important conclusions of this very remarkable
paper—a paper which seems to have interest to the successors of
Aristarchus generation after generation, since this alone of all the writings
of the great astronomer has been preserved. How widely the exact results of
the measurements of Aristarchus, differ from the truth, we have pointed out
as we progressed. But let it be repeated that this detracts little from the
credit of the astronomer who had such clear and correct conceptions of the
relations of the heavenly bodies and who invented such correct methods of
measurement. Let it be particularly observed, however, that all the
conclusions of Aristarchus are stated in relative terms. He nowhere attempts
to estimate the precise size of the earth, of the moon, or of the sun, or the

actual distance of one of these bodies from another. The obvious reason for
this is that no data were at hand from which to make such precise
measurements. Had Aristarchus known the size of any one of the bodies in
question, he might readily, of course, have determined the size of the others
by the mere application of his relative scale; but he had no means of
determining the size of the earth, and to this extent his system of
measurements remained imperfect. Where Aristarchus halted, however,
another worker of the same period took the task in hand and by an
altogether wonderful measurement determined the size of the earth, and
thus brought the scientific theories of cosmology to their climax. This
worthy supplementor of the work of Aristarchus was Eratosthenes of
Alexandria.
ERATOSTHENES, "THE SURVEYOR OF THE WORLD"
An altogether remarkable man was this native of Cyrene, who came to
Alexandria from Athens to be the chief librarian of Ptolemy Euergetes. He
was not merely an astronomer and a geographer, but a poet and grammarian
as well. His contemporaries jestingly called him Beta the Second, because
he was said through the universality of his attainments to be "a second
Plato" in philosophy, "a second Thales" in astronomy, and so on throughout
the list. He was also called the "surveyor of the world," in recognition of his
services to geography. Hipparchus said of him, perhaps half jestingly, that
he had studied astronomy as a geographer and geography as an astronomer.
It is not quite clear whether the epigram was meant as compliment or as
criticism. Similar phrases have been turned against men of versatile talent
in every age. Be that as it may, Eratosthenes passed into history as the
father of scientific geography and of scientific chronology; as the
astronomer who first measured the obliquity of the ecliptic; and as the
inventive genius who performed the astounding feat of measuring the size
of the globe on which we live at a time when only a relatively small portion
of that globe's surface was known to civilized man. It is no discredit to
approach astronomy as a geographer and geography as an astronomer if the
results are such as these. What Eratosthenes really did was to approach both
astronomy and geography from two seemingly divergent points of attack—
namely, from the stand-point of the geometer and also from that of the poet.
Perhaps no man in any age has brought a better combination of observing
and imaginative faculties to the aid of science.

Nearly all the discoveries of Eratosthenes are associated with
observations of the shadows cast by the sun. We have seen that, in the study
of the heavenly bodies, much depends on the measurement of angles. Now
the easiest way in which angles can be measured, when solar angles are in
question, is to pay attention, not to the sun itself, but to the shadow that it
casts. We saw that Thales made some remarkable measurements with the
aid of shadows, and we have more than once referred to the gnomon, which
is the most primitive, but which long remained the most important, of
astronomical instruments. It is believed that Eratosthenes invented an
important modification of the gnomon which was elaborated afterwards by
Hipparchus and called an armillary sphere. This consists essentially of a
small gnomon, or perpendicular post, attached to a plane representing the
earth's equator and a hemisphere in imitation of the earth's surface. With the
aid of this, the shadow cast by the sun could be very accurately measured. It
involves no new principle. Every perpendicular post or object of any kind
placed in the sunlight casts a shadow from which the angles now in
question could be roughly measured. The province of the armillary sphere
was to make these measurements extremely accurate.
With the aid of this implement, Eratosthenes carefully noted the longest
and the shortest shadows cast by the gnomon—that is to say, the shadows
cast on the days of the solstices. He found that the distance between the
tropics thus measured represented 47 degrees 42' 39" of arc. One-half of
this, or 23 degrees 5,' 19.5", represented the obliquity of the ecliptic—that is
to say, the angle by which the earth's axis dipped from the perpendicular
with reference to its orbit. This was a most important observation, and
because of its accuracy it has served modern astronomers well for
comparison in measuring the trifling change due to our earth's slow,
swinging wobble. For the earth, be it understood, like a great top spinning
through space, holds its position with relative but not quite absolute fixity.
It must not be supposed, however, that the experiment in question was quite
new with Eratosthenes. His merit consists rather in the accuracy with which
he made his observation than in the novelty of the conception; for it is
recorded that Eudoxus, a full century earlier, had remarked the obliquity of
the ecliptic. That observer had said that the obliquity corresponded to the
side of a pentadecagon, or fifteen-sided figure, which is equivalent in
modern phraseology to twenty-four degrees of arc. But so little is known
regarding the way in which Eudoxus reached his estimate that the

measurement of Eratosthenes is usually spoken of as if it were the first
effort of the kind.
Much more striking, at least in its appeal to the popular imagination, was
that other great feat which Eratosthenes performed with the aid of his
perfected gnomon—the measurement of the earth itself. When we reflect
that at this period the portion of the earth open to observation extended only
from the Straits of Gibraltar on the west to India on the east, and from the
North Sea to Upper Egypt, it certainly seems enigmatical—at first thought
almost miraculous—that an observer should have been able to measure the
entire globe. That he should have accomplished this through observation of
nothing more than a tiny bit of Egyptian territory and a glimpse of the sun's
shadow makes it seem but the more wonderful. Yet the method of
Eratosthenes, like many another enigma, seems simple enough once it is
explained. It required but the application of a very elementary knowledge of
the geometry of circles, combined with the use of a fact or two from local
geography—which detracts nothing from the genius of the man who could
reason from such simple premises to so wonderful a conclusion.
Stated in a few words, the experiment of Eratosthenes was this. His
geographical studies had taught him that the town of Syene lay directly
south of Alexandria, or, as we should say, on the same meridian of latitude.
He had learned, further, that Syene lay directly under the tropic, since it was
reported that at noon on the day of the summer solstice the gnomon there
cast no shadow, while a deep well was illumined to the bottom by the sun.
A third item of knowledge, supplied by the surveyors of Ptolemy, made the
distance between Syene and Alexandria five thousand stadia. These, then,
were the preliminary data required by Eratosthenes. Their significance
consists in the fact that here is a measured bit of the earth's arc five
thousand stadia in length. If we could find out what angle that bit of arc
subtends, a mere matter of multiplication would give us the size of the
earth. But how determine this all-important number? The answer came
through reflection on the relations of concentric circles. If you draw any
number of circles, of whatever size, about a given centre, a pair of radii
drawn from that centre will cut arcs of the same relative size from all the
circles. One circle may be so small that the actual arc subtended by the radii
in a given case may be but an inch in length, while another circle is so large
that its corresponding are is measured in millions of miles; but in each case
the same number of so-called degrees will represent the relation of each arc

to its circumference. Now, Eratosthenes knew, as just stated, that the sun,
when on the meridian on the day of the summer solstice, was directly over
the town of Syene. This meant that at that moment a radius of the earth
projected from Syene would point directly towards the sun. Meanwhile, of
course, the zenith would represent the projection of the radius of the earth
passing through Alexandria. All that was required, then, was to measure, at
Alexandria, the angular distance of the sun from the zenith at noon on the
day of the solstice to secure an approximate measurement of the arc of the
sun's circumference, corresponding to the arc of the earth's surface
represented by the measured distance between Alexandria and Syene.
The reader will observe that the measurement could not be absolutely
accurate, because it is made from the surface of the earth, and not from the
earth's centre, but the size of the earth is so insignificant in comparison with
the distance of the sun that this slight discrepancy could be disregarded.
The way in which Eratosthenes measured this angle was very simple. He
merely measured the angle of the shadow which his perpendicular gnomon
at Alexandria cast at mid-day on the day of the solstice, when, as already
noted, the sun was directly perpendicular at Syene. Now a glance at the
diagram will make it clear that the measurement of this angle of the shadow
is merely a convenient means of determining the precisely equal opposite
angle subtending an arc of an imaginary circle passing through the sun; the
are which, as already explained, corresponds with the arc of the earth's
surface represented by the distance between Alexandria and Syene. He
found this angle to represent 7 degrees 12', or one-fiftieth of the circle. Five
thousand stadia, then, represent one-fiftieth of the earth's circumference; the
entire circumference being, therefore, 250,000 stadia. Unfortunately, we do
not know which one of the various measurements used in antiquity is
represented by the stadia of Eratosthenes. According to the researches of
Lepsius, however, the stadium in question represented 180 meters, and this
would make the earth, according to the measurement of Eratosthenes, about
twenty-eight thousand miles in circumference, an answer sufficiently exact
to justify the wonder which the experiment excited in antiquity, and the
admiration with which it has ever since been regarded.
{illustration caption = DIAGRAM TO ILLUSTRATE
ERATOSTHENES' MEASUREMENT OF THE GLOBE

FIG. 1. AF is a gnomon at Alexandria; SB a gnomon at Svene; IS and JK
represent the sun's rays. The angle actually measured by Eratosthenes is
KFA, as determined by the shadow cast by the gnomon AF. This angle is
equal to the opposite angle JFL, which measures the sun's distance from the
zenith; and which is also equal to the angle AES—to determine the Size of
which is the real object of the entire measurement.
FIG. 2 shows the form of the gnomon actually employed in antiquity. The
hemisphere KA being marked with a scale, it is obvious that in actual
practice Eratosthenes required only to set his gnomon in the sunlight at the
proper moment, and read off the answer to his problem at a glance. The
simplicity of the method makes the result seem all the more wonderful.}
Of course it is the method, and not its details or its exact results, that
excites our interest. And beyond question the method was an admirable one.
Its result, however, could not have been absolutely accurate, because, while
correct in principle, its data were defective. In point of fact Syene did not
lie precisely on the same meridian as Alexandria, neither did it lie exactly
on the tropic. Here, then, are two elements of inaccuracy. Moreover, it is
doubtful whether Eratosthenes made allowance, as he should have done, for
the semi-diameter of the sun in measuring the angle of the shadow. But
these are mere details, scarcely worthy of mention from our present stand-
point. What perhaps is deserving of more attention is the fact that this
epoch-making measurement of Eratosthenes may not have been the first
one to be made. A passage of Aristotle records that the size of the earth was
said to be 400,000 stadia. Some commentators have thought that Aristotle
merely referred to the area of the inhabited portion of the earth and not to
the circumference of the earth itself, but his words seem doubtfully
susceptible of this interpretation; and if he meant, as his words seem to
imply, that philosophers of his day had a tolerably precise idea of the globe,
we must assume that this idea was based upon some sort of measurement.
The recorded size, 400,000 stadia, is a sufficient approximation to the truth
to suggest something more than a mere unsupported guess. Now, since
Aristotle died more than fifty years before Eratosthenes was born, his report
as to the alleged size of the earth certainly has a suggestiveness that cannot
be overlooked; but it arouses speculations without giving an inkling as to
their solution. If Eratosthenes had a precursor as an earth-measurer, no hint
or rumor has come down to us that would enable us to guess who that
precursor may have been. His personality is as deeply enveloped in the

mists of the past as are the personalities of the great prehistoric discoverers.
For the purpose of the historian, Eratosthenes must stand as the inventor of
the method with which his name is associated, and as the first man of whom
we can say with certainty that he measured the size of the earth. Right
worthily, then, had the Alexandrian philosopher won his proud title of
"surveyor of the world."
HIPPARCHUS, "THE LOVER OF TRUTH"
Eratosthenes outlived most of his great contemporaries. He saw the
turning of that first and greatest century of Alexandrian science, the third
century before our era. He died in the year 196 B.C., having, it is said,
starved himself to death to escape the miseries of blindness;—to the
measurer of shadows, life without light seemed not worth the living.
Eratosthenes left no immediate successor. A generation later, however,
another great figure appeared in the astronomical world in the person of
Hipparchus, a man who, as a technical observer, had perhaps no peer in the
ancient world: one who set so high a value upon accuracy of observation as
to earn the title of "the lover of truth." Hipparchus was born at Nicaea, in
Bithynia, in the year 160 B.C. His life, all too short for the interests of
science, ended in the year 125 B.C. The observations of the great
astronomer were made chiefly, perhaps entirely, at Rhodes. A
misinterpretation of Ptolemy's writings led to the idea that Hipparchus,
performed his chief labors in Alexandria, but it is now admitted that there is
no evidence for this. Delambre doubted, and most subsequent writers
follow him here, whether Hipparchus ever so much as visited Alexandria. In
any event there seems to be no question that Rhodes may claim the honor of
being the chief site of his activities.
It was Hipparchus whose somewhat equivocal comment on the work of
Eratosthenes we have already noted. No counter-charge in kind could be
made against the critic himself; he was an astronomer pure and simple. His
gift was the gift of accurate observation rather than the gift of imagination.
No scientific progress is possible without scientific guessing, but
Hipparchus belonged to that class of observers with whom hypothesis is
held rigidly subservient to fact. It was not to be expected that his mind
would be attracted by the heliocentric theory of Aristarchus. He used the
facts and observations gathered by his great predecessor of Samos, but he
declined to accept his theories. For him the world was central; his problem

was to explain, if he could, the irregularities of motion which sun, moon,
and planets showed in their seeming circuits about the earth. Hipparchus
had the gnomon of Eratosthenes—doubtless in a perfected form—to aid
him, and he soon proved himself a master in its use. For him, as we have
said, accuracy was everything; this was the one element that led to all his
great successes.
Perhaps his greatest feat was to demonstrate the eccentricity of the sun's
seeming orbit. We of to-day, thanks to Keppler and his followers, know that
the earth and the other planetary bodies in their circuit about the sun
describe an ellipse and not a circle. But in the day of Hipparchus, though
the ellipse was recognized as a geometrical figure (it had been described
and named along with the parabola and hyperbola by Apollonius of Perga,
the pupil of Euclid), yet it would have been the rankest heresy to suggest an
elliptical course for any heavenly body. A metaphysical theory, as
propounded perhaps by the Pythagoreans but ardently supported by
Aristotle, declared that the circle is the perfect figure, and pronounced it
inconceivable that the motions of the spheres should be other than circular.
This thought dominated the mind of Hipparchus, and so when his careful
measurements led him to the discovery that the northward and southward
journeyings of the sun did not divide the year into four equal parts, there
was nothing open to him but to either assume that the earth does not lie
precisely at the centre of the sun's circular orbit or to find some alternative
hypothesis.
In point of fact, the sun (reversing the point of view in accordance with
modern discoveries) does lie at one focus of the earth's elliptical orbit, and
therefore away from the physical centre of that orbit; in other words, the
observations of Hipparchus were absolutely accurate. He was quite correct
in finding that the sun spends more time on one side of the equator than on
the other. When, therefore, he estimated the relative distance of the earth
from the geometrical centre of the sun's supposed circular orbit, and spoke
of this as the measure of the sun's eccentricity, he propounded a theory in
which true data of observation were curiously mingled with a positively
inverted theory. That the theory of Hipparchus was absolutely consistent
with all the facts of this particular observation is the best evidence that
could be given of the difficulties that stood in the way of a true explanation
of the mechanism of the heavens.

But it is not merely the sun which was observed to vary in the speed of
its orbital progress; the moon and the planets also show curious
accelerations and retardations of motion. The moon in particular received
most careful attention from Hipparchus. Dominated by his conception of
the perfect spheres, he could find but one explanation of the anomalous
motions which he observed, and this was to assume that the various
heavenly bodies do not fly on in an unvarying arc in their circuit about the
earth, but describe minor circles as they go which can be likened to nothing
so tangibly as to a light attached to the rim of a wagon-wheel in motion. If
such an invisible wheel be imagined as carrying the sun, for example, on its
rim, while its invisible hub follows unswervingly the circle of the sun's
mean orbit (this wheel, be it understood, lying in the plane of the orbit, not
at right-angles to it), then it must be obvious that while the hub remains
always at the same distance from the earth, the circling rim will carry the
sun nearer the earth, then farther away, and that while it is traversing that
portion of the are which brings it towards the earth, the actual forward
progress of the sun will be retarded notwithstanding the uniform motion of
the hub, just as it will be accelerated in the opposite arc. Now, if we
suppose our sun-bearing wheel to turn so slowly that the sun revolves but
once about its imaginary hub while the wheel itself is making the entire
circuit of the orbit, we shall have accounted for the observed fact that the
sun passes more quickly through one-half of the orbit than through the
other. Moreover, if we can visualize the process and imagine the sun to have
left a visible line of fire behind him throughout the course, we shall see that
in reality the two circular motions involved have really resulted in
producing an elliptical orbit.
The idea is perhaps made clearer if we picture the actual progress of the
lantern attached to the rim of an ordinary cart-wheel. When the cart is
drawn forward the lantern is made to revolve in a circle as regards the hub
of the wheel, but since that hub is constantly going forward, the actual path
described by the lantern is not a circle at all but a waving line. It is precisely
the same with the imagined course of the sun in its orbit, only that we view
these lines just as we should view the lantern on the wheel if we looked at it
from directly above and not from the side. The proof that the sun is
describing this waving line, and therefore must be considered as attached to
an imaginary wheel, is furnished, as it seemed to Hipparchus, by the
observed fact of the sun's varying speed.

That is one way of looking at the matter. It is an hypothesis that explains
the observed facts—after a fashion, and indeed a very remarkable fashion.
The idea of such an explanation did not originate with Hipparchus. The
germs of the thought were as old as the Pythagorean doctrine that the earth
revolves about a centre that we cannot see. Eudoxus gave the conception
greater tangibility, and may be considered as the father of this doctrine of
wheels—epicycles, as they came to be called. Two centuries before the time
of Hipparchus he conceived a doctrine of spheres which Aristotle found
most interesting, and which served to explain, along the lines we have just
followed, the observed motions of the heavenly bodies. Calippus, the
reformer of the calendar, is said to have carried an account of this theory to
Aristotle. As new irregularities of motion of the sun, moon, and planetary
bodies were pointed out, new epicycles were invented. There is no limit to
the number of imaginary circles that may be inscribed about an imaginary
centre, and if we conceive each one of these circles to have a proper motion
of its own, and each one to carry the sun in the line of that motion, except as
it is diverted by the other motions—if we can visualize this complex
mingling of wheels—we shall certainly be able to imagine the heavenly
body which lies at the juncture of all the rims, as being carried forward in as
erratic and wobbly a manner as could be desired. In other words, the theory
of epicycles will account for all the facts of the observed motions of all the
heavenly bodies, but in so doing it fills the universe with a most
bewildering network of intersecting circles. Even in the time of Calippus
fifty-five of these spheres were computed.
We may well believe that the clear-seeing Aristarchus would look
askance at such a complex system of imaginary machinery. But Hipparchus,
pre-eminently an observer rather than a theorizer, seems to have been
content to accept the theory of epicycles as he found it, though his studies
added to its complexities; and Hipparchus was the dominant scientific
personality of his century. What he believed became as a law to his
immediate successors. His tenets were accepted as final by their great
popularizer, Ptolemy, three centuries later; and so the heliocentric theory of
Aristarchus passed under a cloud almost at the hour of its dawning, there to
remain obscured and forgotten for the long lapse of centuries. A thousand
pities that the greatest observing astronomer of antiquity could not, like one
of his great precursors, have approached astronomy from the stand-point of
geography and poetry. Had he done so, perhaps he might have reflected,

like Aristarchus before him, that it seems absurd for our earth to hold the
giant sun in thraldom; then perhaps his imagination would have reached out
to the heliocentric doctrine, and the cobweb hypothesis of epicycles, with
that yet more intangible figment of the perfect circle, might have been
wiped away.
But it was not to be. With Aristarchus the scientific imagination had
reached its highest flight; but with Hipparchus it was beginning to settle
back into regions of foggier atmosphere and narrower horizons. For what,
after all, does it matter that Hipparchus should go on to measure the precise
length of the year and the apparent size of the moon's disk; that he should
make a chart of the heavens showing the place of 1080 stars; even that he
should discover the precession of the equinox;—what, after all, is the
significance of these details as against the all-essential fact that the greatest
scientific authority of his century—the one truly heroic scientific figure of
his epoch—should have lent all the forces of his commanding influence to
the old, false theory of cosmology, when the true theory had been
propounded and when he, perhaps, was the only man in the world who
might have substantiated and vitalized that theory? It is easy to overestimate
the influence of any single man, and, contrariwise, to underestimate the
power of the Zeitgeist. But when we reflect that the doctrines of
Hipparchus, as promulgated by Ptolemy, became, as it were, the last word
of astronomical science for both the Eastern and Western worlds, and so
continued after a thousand years, it is perhaps not too much to say that
Hipparchus, "the lover of truth," missed one of the greatest opportunities for
the promulgation of truth ever vouchsafed to a devotee of pure science.
But all this, of course, detracts nothing from the merits of Hipparchus as
an observing astronomer. A few words more must be said as to his specific
discoveries in this field. According to his measurement, the tropic year
consists of 365 days, 5 hours, and 49 minutes, varying thus only 12 seconds
from the true year, as the modern astronomer estimates it. Yet more
remarkable, because of the greater difficulties involved, was Hipparchus's
attempt to measure the actual distance of the moon. Aristarchus had made a
similar attempt before him. Hipparchus based his computations on studies
of the moon in eclipse, and he reached the conclusion that the distance of
the moon is equal to 59 radii of the earth (in reality it is 60.27 radii). Here,
then, was the measure of the base-line of that famous triangle with which
Aristarchus had measured the distance of the sun. Hipparchus must have

known of that measurement, since he quotes the work of Aristarchus in
other fields. Had he now but repeated the experiment of Aristarchus, with
his perfected instruments and his perhaps greater observational skill, he was
in position to compute the actual distance of the sun in terms not merely of
the moon's distance but of the earth's radius. And now there was the
experiment of Eratosthenes to give the length of that radius in precise terms.
In other words, Hipparchus might have measured the distance of the sun in
stadia. But if he had made the attempt—and, indeed, it is more than likely
that he did so—the elements of error in his measurements would still have
kept him wide of the true figures.
The chief studies of Hipparchus were directed, as we have seen, towards
the sun and the moon, but a phenomenon that occurred in the year 134 B.C.
led him for a time to give more particular attention to the fixed stars. The
phenomenon in question was the sudden outburst of a new star; a
phenomenon which has been repeated now and again, but which is
sufficiently rare and sufficiently mysterious to have excited the unusual
attention of astronomers in all generations. Modern science offers an
explanation of the phenomenon, as we shall see in due course. We do not
know that Hipparchus attempted to explain it, but he was led to make a
chart of the heavens, probably with the idea of guiding future observers in
the observation of new stars. Here again Hipparchus was not altogether an
innovator, since a chart showing the brightest stars had been made by
Eratosthenes; but the new charts were much elaborated.
The studies of Hipparchus led him to observe the stars chiefly with
reference to the meridian rather than with reference to their rising, as had
hitherto been the custom. In making these studies of the relative position of
the stars, Hipparchus was led to compare his observations with those of the
Babylonians, which, it was said, Alexander had caused to be transmitted to
Greece. He made use also of the observations of Aristarchus and others of
his Greek precursors. The result of his comparisons proved that the sphere
of the fixed stars had apparently shifted its position in reference to the plane
of the sun's orbit—that is to say, the plane of the ecliptic no longer seemed
to cut the sphere of the fixed stars at precisely the point where the two
coincided in former centuries. The plane of the ecliptic must therefore be
conceived as slowly revolving in such a way as gradually to circumnavigate
the heavens. This important phenomenon is described as the precession of
the equinoxes.

It is much in question whether this phenomenon was not known to the
ancient Egyptian astronomers; but in any event, Hipparchus is to be
credited with demonstrating the fact and making it known to the Western
world. A further service was rendered theoretical astronomy by Hipparchus
through his invention of the planosphere, an instrument for the
representation of the mechanism of the heavens. His computations of the
properties of the spheres led him also to what was virtually a discovery of
the method of trigonometry, giving him, therefore, a high position in the
field of mathematics. All in all, then, Hipparchus is a most heroic figure. He
may well be considered the greatest star-gazer of antiquity, though he
cannot, without injustice to his great precursors, be allowed the title which
is sometimes given him of "father of systematic astronomy."
CTESIBIUS AND HERO: MAGICIANS OF ALEXANDRIA
Just about the time when Hipparchus was working out at Rhodes his
puzzles of celestial mechanics, there was a man in Alexandria who was
exercising a strangely inventive genius over mechanical problems of
another sort; a man who, following the example set by Archimedes a
century before, was studying the problems of matter and putting his studies
to practical application through the invention of weird devices. The man's
name was Ctesibius. We know scarcely more of him than that he lived in
Alexandria, probably in the first half of the second century B.C. His
antecedents, the place and exact time of his birth and death, are quite
unknown. Neither are we quite certain as to the precise range of his studies
or the exact number of his discoveries. It appears that he had a pupil named
Hero, whose personality, unfortunately, is scarcely less obscure than that of
his master, but who wrote a book through which the record of the master's
inventions was preserved to posterity. Hero, indeed, wrote several books,
though only one of them has been preserved. The ones that are lost bear the
following suggestive titles: On the Construction of Slings; On the
Construction of Missiles; On the Automaton; On the Method of Lifting
Heavy Bodies; On the Dioptric or Spying-tube. The work that remains is
called Pneumatics, and so interesting a work it is as to make us doubly
regret the loss of its companion volumes. Had these other books been
preserved we should doubtless have a clearer insight than is now possible
into some at least of the mechanical problems that exercised the minds of
the ancient philosophers. The book that remains is chiefly concerned, as its
name implies, with the study of gases, or, rather, with the study of a single

gas, this being, of course, the air. But it tells us also of certain studies in the
dynamics of water that are most interesting, and for the historian of science
most important.
Unfortunately, the pupil of Ctesibius, whatever his ingenuity, was a man
with a deficient sense of the ethics of science. He tells us in his preface that
the object of his book is to record some ingenious discoveries of others,
together with additional discoveries of his own, but nowhere in the book
itself does he give us the, slightest clew as to where the line is drawn
between the old and the new. Once, in discussing the weight of water, he
mentions the law of Archimedes regarding a floating body, but this is the
only case in which a scientific principle is traced to its source or in which
credit is given to any one for a discovery. This is the more to be regretted
because Hero has discussed at some length the theories involved in the
treatment of his subject. This reticence on the part of Hero, combined with
the fact that such somewhat later writers as Pliny and Vitruvius do not
mention Hero's name, while they frequently mention the name of his
master, Ctesibius, has led modern critics to a somewhat sceptical attitude
regarding the position of Hero as an actual discoverer.
The man who would coolly appropriate some discoveries of others under
cloak of a mere prefatorial reference was perhaps an expounder rather than
an innovator, and had, it is shrewdly suspected, not much of his own to
offer. Meanwhile, it is tolerably certain that Ctesibius was the discoverer of
the principle of the siphon, of the forcing-pump, and of a pneumatic organ.
An examination of Hero's book will show that these are really the chief
principles involved in most of the various interesting mechanisms which he
describes. We are constrained, then, to believe that the inventive genius who
was really responsible for the mechanisms we are about to describe was
Ctesibius, the master. Yet we owe a debt of gratitude to Hero, the pupil, for
having given wider vogue to these discoveries, and in particular for the
discussion of the principles of hydrostatics and pneumatics contained in the
introduction to his book. This discussion furnishes us almost our only
knowledge as to the progress of Greek philosophers in the field of
mechanics since the time of Archimedes.
The main purpose of Hero in his preliminary thesis has to do with the
nature of matter, and recalls, therefore, the studies of Anaxagoras and
Democritus. Hero, however, approaches his subject from a purely material

or practical stand-point. He is an explicit champion of what we nowadays
call the molecular theory of matter. "Every body," he tells us, "is composed
of minute particles, between which are empty spaces less than these
particles of the body. It is, therefore, erroneous to say that there is no
vacuum except by the application of force, and that every space is full
either of air or water or some other substance. But in proportion as any one
of these particles recedes, some other follows it and fills the vacant space;
therefore there is no continuous vacuum, except by the application of some
force (like suction)—that is to say, an absolute vacuum is never found,
except as it is produced artificially." Hero brings forward some thoroughly
convincing proofs of the thesis he is maintaining. "If there were no void
places between the particles of water," he says, "the rays of light could not
penetrate the water; moreover, another liquid, such as wine, could not
spread itself through the water, as it is observed to do, were the particles of
water absolutely continuous." The latter illustration is one the validity of
which appeals as forcibly to the physicists of to-day as it did to Hero. The
same is true of the argument drawn from the compressibility of gases. Hero
has evidently made a careful study of this subject. He knows that an
inverted tube full of air may be immersed in water without becoming wet
on the inside, proving that air is a physical substance; but he knows also
that this same air may be caused to expand to a much greater bulk by the
application of heat, or may, on the other hand, be condensed by pressure, in
which case, as he is well aware, the air exerts force in the attempt to regain
its normal bulk. But, he argues, surely we are not to believe that the
particles of air expand to fill all the space when the bulk of air as a whole
expands under the influence of heat; nor can we conceive that the particles
of normal air are in actual contact, else we should not be able to compress
the air. Hence his conclusion, which, as we have seen, he makes general in
its application to all matter, that there are spaces, or, as he calls them, vacua,
between the particles that go to make up all substances, whether liquid,
solid, or gaseous.
Here, clearly enough, was the idea of the "atomic" nature of matter
accepted as a fundamental notion. The argumentative attitude assumed by
Hero shows that the doctrine could not be expected to go unchallenged.
But, on the other hand, there is nothing in his phrasing to suggest an
intention to claim originality for any phase of the doctrine. We may infer
that in the three hundred years that had elapsed since the time of

Anaxagoras, that philosopher's idea of the molecular nature of matter had
gained fairly wide currency. As to the expansive power of gas, which Hero
describes at some length without giving us a clew to his authorities, we may
assume that Ctesibius was an original worker, yet the general facts involved
were doubtless much older than his day. Hero, for example, tells us of the
cupping-glass used by physicians, which he says is made into a vacuum by
burning up the air in it; but this apparatus had probably been long in use,
and Hero mentions it not in order to describe the ordinary cupping-glass
which is referred to, but a modification of it. He refers to the old form as if
it were something familiar to all.
Again, we know that Empedocles studied the pressure of the air in the
fifth century B.C., and discovered that it would support a column of water
in a closed tube, so this phase of the subject is not new. But there is no hint
anywhere before this work of Hero of a clear understanding that the
expansive properties of the air when compressed, or when heated, may be
made available as a motor power. Hero, however, has the clearest notions
on the subject and puts them to the practical test of experiment. Thus he
constructs numerous mechanisms in which the expansive power of air
under pressure is made to do work, and others in which the same end is
accomplished through the expansive power of heated air. For example, the
doors of a temple are made to swing open automatically when a fire is
lighted on a distant altar, closing again when the fire dies out—effects
which must have filled the minds of the pious observers with bewilderment
and wonder, serving a most useful purpose for the priests, who alone, we
may assume, were in the secret. There were two methods by which this
apparatus was worked. In one the heated air pressed on the water in a close
retort connected with the altar, forcing water out of the retort into a bucket,
which by its weight applied a force through pulleys and ropes that turned
the standards on which the temple doors revolved. When the fire died down
the air contracted, the water was siphoned back from the bucket, which,
being thus lightened, let the doors close again through the action of an
ordinary weight. The other method was a slight modification, in which the
retort of water was dispensed with and a leather sack like a large football
substitued. The ropes and pulleys were connected with this sack, which
exerted a pull when the hot air expanded, and which collapsed and thus
relaxed its strain when the air cooled. A glance at the illustrations taken
from Hero's book will make the details clear.

Other mechanisms utilized a somewhat different combination of weights,
pulleys, and siphons, operated by the expansive power of air, unheated but
under pressure, such pressure being applied with a force-pump, or by the
weight of water running into a closed receptacle. One such mechanism
gives us a constant jet of water or perpetual fountain. Another curious
application of the principle furnishes us with an elaborate toy, consisting of
a group of birds which alternately whistle or are silent, while an owl seated
on a neighboring perch turns towards the birds when their song begins and
away from them when it ends. The "singing" of the birds, it must be
explained, is produced by the expulsion of air through tiny tubes passing up
through their throats from a tank below. The owl is made to turn by a
mechanism similar to that which manipulates the temple doors. The
pressure is supplied merely by a stream of running water, and the periodical
silence of the birds is due to the fact that this pressure is relieved through
the automatic siphoning off of the water when it reaches a certain height.
The action of the siphon, it may be added, is correctly explained by Hero as
due to the greater weight of the water in the longer arm of the bent tube. As
before mentioned, the siphon is repeatedly used in these mechanisms of
Hero. The diagram will make clear the exact application of it in the present
most ingenious mechanism. We may add that the principle of the whistle
was a favorite one of Hero. By the aid of a similar mechanism he brought
about the blowing of trumpets when the temple doors were opened, a
phenomenon which must greatly have enhanced the mystification. It is
possible that this principle was utilized also in connection with statues to
produce seemingly supernatural effects. This may be the explanation of the
tradition of the speaking statue in the temple of Ammon at Thebes.
{illustration caption = DEVICE FOR CAUSING THE DOORS OF THE
TEMPLE TO OPEN WHEN THE FIRE ON THE ALTAR IS LIGHTED
(Air heated in the altar F drives water from the closed receptacle H through
the tube KL into the bucket M, which descends through gravity, thus
opening the doors. When the altar cools, the air contracts, the water is
sucked from the bucket, and the weight and pulley close the doors.)}
{illustration caption = THE STEAM-ENGINE OF HERO (The steam
generated in the receptacle AB passes through the tube EF into the globe,
and escapes through the bent tubes H and K, causing the globe to rotate on
the axis LG.)}

The utilization of the properties of compressed air was not confined,
however, exclusively to mere toys, or to produce miraculous effects. The
same principle was applied to a practical fire-engine, worked by levers and
force-pumps; an apparatus, in short, altogether similar to that still in use in
rural districts. A slightly different application of the motive power of
expanding air is furnished in a very curious toy called "the dancing figures."
In this, air heated in a retort like a miniature altar is allowed to escape
through the sides of two pairs of revolving arms precisely like those of the
ordinary revolving fountain with which we are accustomed to water our
lawns, the revolving arms being attached to a plane on which several pairs
of statuettes representing dancers are placed, An even more interesting
application of this principle of setting a wheel in motion is furnished in a
mechanism which must be considered the earliest of steam-engines. Here,
as the name implies, the gas supplying the motive power is actually steam.
The apparatus made to revolve is a globe connected with the steam-retort
by a tube which serves as one of its axes, the steam escaping from the globe
through two bent tubes placed at either end of an equatorial diameter. It
does not appear that Hero had any thought of making practical use of this
steam-engine. It was merely a curious toy—nothing more. Yet had not the
age that succeeded that of Hero been one in which inventive genius was
dormant, some one must soon have hit upon the idea that this steam-engine
might be improved and made to serve a useful purpose. As the case stands,
however, there was no advance made upon the steam motor of Hero for
almost two thousand years. And, indeed, when the practical application of
steam was made, towards the close of the eighteenth century, it was made
probably quite without reference to the experiment of Hero, though
knowledge of his toy may perhaps have given a clew to Watt or his
predecessors.
{illustration caption = THE SLOT-MACHINE OF HERO (The coin
introduced at A falls on the lever R, and by its weight opens the valve S,
permitting the liquid to escape through the invisible tube LM. As the lever
tips, the coin slides off and the valve closes. The liquid in tank must of
course be kept above F.)}
In recent times there has been a tendency to give to this steam-engine of
Hero something more than full meed of appreciation. To be sure, it marked
a most important principle in the conception that steam might be used as a
motive power, but, except in the demonstration of this principle, the

mechanism of Hero was much too primitive to be of any importance. But
there is one mechanism described by Hero which was a most explicit
anticipation of a device, which presumably soon went out of use, and which
was not reinvented until towards the close of the nineteenth century. This
was a device which has become familiar in recent times as the penny-in-
the-slot machine. When towards the close of the nineteenth century some
inventive craftsman hit upon the idea of an automatic machine to supply
candy, a box of cigarettes, or a whiff of perfumery, he may or may not have
borrowed his idea from the slot-machine of Hero; but in any event, instead
of being an innovator he was really two thousand years behind the times,
for the slot-machine of Hero is the precise prototype of these modern ones.
The particular function which the mechanism of Hero was destined to
fulfil was the distribution of a jet of water, presumably used for sacramental
purposes, which was given out automatically when a five-drachma coin was
dropped into the slot at the top of the machine. The internal mechanism of
the machine was simple enough, consisting merely of a lever operating a
valve which was opened by the weight of the coin dropping on the little
shelf at the end of the lever, and which closed again when the coin slid off
the shelf. The illustration will show how simple this mechanism was. Yet to
the worshippers, who probably had entered the temple through doors
miraculously opened, and who now witnessed this seemingly intelligent
response of a machine, the result must have seemed mystifying enough;
and, indeed, for us also, when we consider how relatively crude was the
mechanical knowledge of the time, this must seem nothing less than
marvellous. As in imagination we walk up to the sacred tank, drop our
drachma in the slot, and hold our hand for the spurt of holy-water, can we
realize that this is the land of the Pharaohs, not England or America; that the
kingdom of the Ptolemies is still at its height; that the republic of Rome is
mistress of the world; that all Europe north of the Alps is inhabited solely
by barbarians; that Cleopatra and Julius Caesar are yet unborn; that the
Christian era has not yet begun? Truly, it seems as if there could be no new
thing under the sun.

X. SCIENCE OF THE ROMAN PERIOD
We have seen that the third century B.C. was a time when Alexandrian
science was at its height, but that the second century produced also in
Hipparchus at least one investigator of the very first rank; though, to be
sure, Hipparchus can be called an Alexandrian only by courtesy. In the
ensuing generations the Greek capital at the mouth of the Nile continued to
hold its place as the centre of scientific and philosophical thought. The
kingdom of the Ptolemies still flourished with at least the outward
appearances of its old-time glory, and a company of grammarians and
commentators of no small merit could always be found in the service of the
famous museum and library; but the whole aspect of world-history was
rapidly changing. Greece, after her brief day of political supremacy, was
sinking rapidly into desuetude, and the hard-headed Roman in the West was
making himself master everywhere. While Hipparchus of Rhodes was in his
prime, Corinth, the last stronghold of the main-land of Greece, had fallen
before the prowess of the Roman, and the kingdom of the Ptolemies, though
still nominally free, had begun to come within the sphere of Roman
influence.
Just what share these political changes had in changing the aspect of
Greek thought is a question regarding which difference of opinion might
easily prevail; but there can be no question that, for one reason or another,
the Alexandrian school as a creative centre went into a rapid decline at
about the time of the Roman rise to world-power. There are some
distinguished names, but, as a general rule, the spirit of the times is
reminiscent rather than creative; the workers tend to collate the researches
of their predecessors rather than to make new and original researches for
themselves. Eratosthenes, the inventive world-measurer, was succeeded by
Strabo, the industrious collator of facts; Aristarchus and Hipparchus, the
originators of new astronomical methods, were succeeded by Ptolemy, the
perfecter of their methods and the systematizer of their knowledge.
Meanwhile, in the West, Rome never became a true culture-centre. The
great genius of the Roman was political; the Augustan Age produced a few
great historians and poets, but not a single great philosopher or creative

devotee of science. Cicero, Lucian, Seneca, Marcus Aurelius, give us at best
a reflection of Greek philosophy. Pliny, the one world-famous name in the
scientific annals of Rome, can lay claim to no higher credit than that of a
marvellously industrious collector of facts—the compiler of an
encyclopaedia which contains not one creative touch.
All in all, then, this epoch of Roman domination is one that need detain
the historian of science but a brief moment. With the culmination of Greek
effort in the so-called Hellenistic period we have seen ancient science at its
climax. The Roman period is but a time of transition, marking, as it were, a
plateau on the slope between those earlier heights and the deep, dark valleys
of the Middle Ages. Yet we cannot quite disregard the efforts of such
workers as those we have just named. Let us take a more specific glance at
their accomplishments.
STRABO THE GEOGRAPHER
The earliest of these workers in point of time is Strabo. This most famous
of ancient geographers was born in Amasia, Pontus, about 63 B.C., and
lived to the year 24 A.D., living, therefore, in the age of Caesar and
Augustus, during which the final transformation in the political position of
the kingdom of Egypt was effected. The name of Strabo in a modified form
has become popularized through a curious circumstance. The geographer, it
appears, was afflicted with a peculiar squint of the eyes, hence the name
strabismus, which the modern oculist applies to that particular infirmity.
Fortunately, the great geographer has not been forced to depend upon
hearsay evidence for recognition. His comprehensive work on geography
has been preserved in its entirety, being one of the few expansive classical
writings of which this is true. The other writings of Strabo, however,
including certain histories of which reports have come down to us, are
entirely lost. The geography is in many ways a remarkable book. It is not,
however, a work in which any important new principles are involved.
Rather is it typical of its age in that it is an elaborate compilation and a
critical review of the labors of Strabo's predecessors. Doubtless it contains a
vast deal of new information as to the details of geography—precise areas
and distance, questions of geographical locations as to latitude and zones,
and the like. But however important these details may have been from a
contemporary stand-point, they, of course, can have nothing more than
historical interest to posterity. The value of the work from our present

stand-point is chiefly due to the criticisms which Strabo passes upon his
forerunners, and to the incidental historical and scientific references with
which his work abounds. Being written in this closing period of ancient
progress, and summarizing, as it does, in full detail the geographical
knowledge of the time, it serves as an important guide-mark for the student
of the progress of scientific thought. We cannot do better than briefly to
follow Strabo in his estimates and criticisms of the work of his
predecessors, taking note thus of the point of view from which he himself
looked out upon the world. We shall thus gain a clear idea as to the state of
scientific geography towards the close of the classical epoch.
"If the scientific investigation of any subject be the proper avocation of
the philosopher," says Strabo, "geography, the science of which we propose
to treat, is certainly entitled to a high place; and this is evident from many
considerations. They who first undertook to handle the matter were
distinguished men. Homer, Anaximander the Milesian, and Hecaeus (his
fellow-citizen according to Eratosthenes), Democritus, Eudoxus,
Dicaearchus, and Ephorus, with many others, and after these, Eratosthenes,
Polybius, and Posidonius, all of them philosophers. Nor is the great learning
through which alone this subject can be approached possessed by any but a
person acquainted with both human and divine things, and these attainments
constitute what is called philosophy. In addition to its vast importance in
regard to social life and the art of government, geography unfolds to us a
celestial phenomena, acquaints us with the occupants of the land and ocean,
and the vegetation, fruits, and peculiarities of the various quarters of the
earth, a knowledge of which marks him who cultivates it as a man earnest
in the great problem of life and happiness."
Strabo goes on to say that in common with other critics, including
Hipparchus, he regards Homer as the first great geographer. He has much to
say on the geographical knowledge of the bard, but this need not detain us.
We are chiefly concerned with his comment upon his more recent
predecessors, beginning with Eratosthenes. The constant reference to this
worker shows the important position which he held. Strabo appears neither
as detractor nor as partisan, but as one who earnestly desires the truth.
Sometimes he seems captious in his criticisms regarding some detail, nor is
he always correct in his emendations of the labors of others; but, on the
whole, his work is marked by an evident attempt at fairness. In reading his
book, however, one is forced to the conclusion that Strabo is an investigator

of details, not an original thinker. He seems more concerned with precise
measurements than with questionings as to the open problems of his
science. Whatever he accepts, then, may be taken as virtually the stock
doctrine of the period.
"As the size of the earth," he says, "has been demonstrated by other
writers, we shall here take for granted and receive as accurate what they
have advanced. We shall also assume that the earth is spheroidal, that its
surface is likewise spheroidal and, above all, that bodies have a tendency
towards its centre, which latter point is clear to the perception of the most
average understanding. However, we may show summarily that the earth is
spheroidal, from the consideration that all things, however distant, tend to
its centre, and that every body is attracted towards its centre by gravity. This
is more distinctly proved from observations of the sea and sky, for here the
evidence of the senses and common observation is alone requisite. The
convexity of the sea is a further proof of this to those who have sailed, for
they cannot perceive lights at a distance when placed at the same level as
their eyes, and if raised on high they at once become perceptible to vision
though at the same time farther removed. So when the eye is raised it sees
what before was utterly imperceptible. Homer speaks of this when he says:

"'Lifted up on the vast wave he quickly beheld afar.'

"Sailors as they approach their destination behold the shore continually
raising itself to their view, and objects which had at first seemed low begin
to lift themselves. Our gnomons, also, are, among other things, evidence of
the revolution of the heavenly bodies, and common-sense at once shows us
that if the depth of the earth were infinite such a revolution could not take
place."(1)
Elsewhere Strabo criticises Eratosthenes for having entered into a long
discussion as to the form of the earth. This matter, Strabo thinks, "should
have been disposed of in the compass of a few words." Obviously this
doctrine of the globe's sphericity had, in the course of 600 years, become so
firmly established among the Greek thinkers as to seem almost axiomatic.
We shall see later on how the Western world made a curious recession from
this seemingly secure position under stimulus of an Oriental misconception.
As to the size of the globe, Strabo is disposed to accept without particular
comment the measurements of Eratosthenes. He speaks, however, of "more

recent measurements," referring in particular to that adopted by Posidonius,
according to which the circumference is only about one hundred and eighty
thousand stadia. Posidonius, we may note in passing, was a contemporary
and friend of Cicero, and hence lived shortly before the time of Strabo. His
measurement of the earth was based on observations of a star which barely
rose above the southern horizon at Rhodes as compared with the height of
the same star when observed at Alexandria. This measurement of
Posidonius, together with the even more famous measurement of
Eratosthenes, appears to have been practically the sole guide as to the size
of the earth throughout the later periods of antiquity, and, indeed, until the
later Middle Ages.
As becomes a writer who is primarily geographer and historian rather
than astronomer, Strabo shows a much keener interest in the habitable
portions of the globe than in the globe as a whole. He assures us that this
habitable portion of the earth is a great island, "since wherever men have
approached the termination of the land, the sea, which we designate ocean,
has been met with, and reason assures us of the similarity of this place
which our senses have not been tempted to survey." He points out that
whereas sailors have not circumnavigated the globe, that they had not been
prevented from doing so by any continent, and it seems to him altogether
unlikely that the Atlantic Ocean is divided into two seas by narrow
isthmuses so placed as to prevent circumnavigation. "How much more
probable that it is confluent and uninterrupted. This theory," he adds, "goes
better with the ebb and flow of the ocean. Moreover (and here his reasoning
becomes more fanciful), the greater the amount of moisture surrounding the
earth, the easier would the heavenly bodies be supplied with vapor from
thence." Yet he is disposed to believe, following Plato, that the tradition
"concerning the island of Atlantos might be received as something more
than idle fiction, it having been related by Solon, on the authority of the
Egyptian priests, that this island, almost as large as a continent, was
formerly in existence although now it had disappeared."(2)
In a word, then, Strabo entertains no doubt whatever that it would be
possible to sail around the globe from Spain to India. Indeed, so matter-of-
fact an inference was this that the feat of Columbus would have seemed less
surprising in the first century of our era than it did when actually performed
in the fifteenth century. The terrors of the great ocean held the mariner

back, rather than any doubt as to where he would arrive at the end of the
voyage.
Coupled with the idea that the habitable portion of the earth is an island,
there was linked a tolerably definite notion as to the shape of this island.
This shape Strabo likens to a military cloak. The comparison does not seem
peculiarly apt when we are told presently that the length of the habitable
earth is more than twice its breadth. This idea, Strabo assures us, accords
with the most accurate observations "both ancient and modern." These
observations seemed to show that it is not possible to live in the region
close to the equator, and that, on the other hand, the cold temperature
sharply limits the habitability of the globe towards the north. All the
civilization of antiquity clustered about the Mediterranean, or extended off
towards the east at about the same latitude. Hence geographers came to
think of the habitable globe as having the somewhat lenticular shape which
a crude map of these regions suggests. We have already had occasion to see
that at an earlier day Anaxagoras was perhaps influenced in his conception
of the shape of the earth by this idea, and the constant references of Strabo
impress upon us the thought that this long, relatively narrow area of the
earth's surface is the only one which can be conceived of as habitable.
Strabo had much to tell us concerning zones, which, following
Posidonius, he believes to have been first described by Parmenides. We may
note, however, that other traditions assert that both Thales and Pythagoras
had divided the earth into zones. The number of zones accepted by Strabo is
five, and he criticises Polybius for making the number six. The five zones
accepted by Strabo are as follows: the uninhabitable torrid zone lying in the
region of the equator; a zone on either side of this extending to the tropic;
and then the temperate zones extending in either direction from the tropic to
the arctic regions. There seems to have been a good deal of dispute among
the scholars of the time as to the exact arrangement of these zones, but the
general idea that the north-temperate zone is the part of the earth with
which the geographer deals seemed clearly established. That the south-
temperate zone would also present a habitable area is an idea that is
sometimes suggested, though seldom or never distinctly expressed. It is
probable that different opinions were held as to this, and no direct evidence
being available, a cautiously scientific geographer like Strabo would
naturally avoid the expression of an opinion regarding it. Indeed, his own

words leave us somewhat in doubt as to the precise character of his notion
regarding the zones. Perhaps we shall do best to quote them:
"Let the earth be supposed to consist of five zones. (1) The equatorial
circle described around it. (2) Another parallel to this, and defining the
frigid zone of the northern hemisphere. (3) A circle passing through the
poles and cutting the two preceding circles at right-angles. The northern
hemisphere contains two quarters of the earth, which are bounded by the
equator and circle passing through the poles. Each of these quarters should
be supposed to contain a four-sided district, its northern side being of one-
half of the parallel next the pole, its southern by the half of the equator, and
its remaining sides by two segments of the circle drawn through the poles,
opposite to each other, and equal in length. In one of these (which of them
is of no consequence) the earth which we inhabit is situated, surrounded by
a sea and similar to an island. This, as we said before, is evident both to our
senses and to our reason. But let any one doubt this, it makes no difference
so far as geography is concerned whether you believe the portion of the
earth which we inhabit to be an island or only admit what we know from
experience—namely, that whether you start from the east or the west you
may sail all around it. Certain intermediate spaces may have been left
(unexplored), but these are as likely to be occupied by sea as uninhabited
land. The object of the geographer is to describe known countries. Those
which are unknown he passes over equally with those beyond the limits of
the inhabited earth. It will, therefore, be sufficient for describing the contour
of the island we have been speaking of, if we join by a right line the
outmost points which, up to this time, have been explored by voyagers
along the coast on either side."(3)
We may pass over the specific criticisms of Strabo upon various
explorations that seem to have been of great interest to his contemporaries,
including an alleged trip of one Eudoxus out into the Atlantic, and the
journeyings of Pytheas in the far north. It is Pytheas, we may add, who was
cited by Hipparchus as having made the mistaken observation that the
length of the shadow of the gnomon is the same at Marseilles and
Byzantium, hence that these two places are on the same parallel. Modern
commentators have defended Pytheas as regards this observation, claiming
that it was Hipparchus and not Pytheas who made the second observation
from which the faulty induction was drawn. The point is of no great
significance, however, except as showing that a correct method of

determining the problems of latitude had thus early been suggested. That
faulty observations and faulty application of the correct principle should
have been made is not surprising. Neither need we concern ourselves with
the details as to the geographical distances, which Strabo found so worthy
of criticism and controversy. But in leaving the great geographer we may
emphasize his point of view and that of his contemporaries by quoting three
fundamental principles which he reiterates as being among the "facts
established by natural philosophers." He tells us that "(1) The earth and
heavens are spheroidal. (2) The tendency of all bodies having weight is
towards a centre. (3) Further, the earth being spheroidal and having the
same centre as the heavens, is motionless, as well as the axis that passes
through both it and the heavens. The heavens turn round both the earth and
its axis, from east to west. The fixed stars turn round with it at the same rate
as the whole. These fixed stars follow in their course parallel circles, the
principal of which are the equator, two tropics, and the arctic circles; while
the planets, the sun, and the moon describe certain circles comprehended
within the zodiac."(4)
Here, then, is a curious mingling of truth and error. The Pythagorean
doctrine that the earth is round had become a commonplace, but it would
appear that the theory of Aristarchus, according to which the earth is in
motion, has been almost absolutely forgotten. Strabo does not so much as
refer to it; neither, as we shall see, is it treated with greater respect by the
other writers of the period.
TWO FAMOUS EXPOSITORS—PLINY AND PTOLEMY
While Strabo was pursuing his geographical studies at Alexandria, a
young man came to Rome who was destined to make his name more widely
known in scientific annals than that of any other Latin writer of antiquity.
This man was Plinius Secundus, who, to distinguish him from his nephew, a
famous writer in another field, is usually spoken of as Pliny the Elder. There
is a famous story to the effect that the great Roman historian Livy on one
occasion addressed a casual associate in the amphitheatre at Rome, and on
learning that the stranger hailed from the outlying Spanish province of the
empire, remarked to him, "Yet you have doubtless heard of my writings
even there." "Then," replied the stranger, "you must be either Livy or
Pliny."

The anecdote illustrates the wide fame which the Roman naturalist
achieved in his own day. And the records of the Middle Ages show that this
popularity did not abate in succeeding times. Indeed, the Natural History of
Pliny is one of the comparatively few bulky writings of antiquity that the
efforts of copyists have preserved to us almost entire. It is, indeed, a
remarkable work and eminently typical of its time; but its author was an
industrious compiler, not a creative genius. As a monument of industry it
has seldom been equalled, and in this regard it seems the more remarkable
inasmuch as Pliny was a practical man of affairs who occupied most of his
life as a soldier fighting the battles of the empire. He compiled his book in
the leisure hours stolen from sleep, often writing by the light of the camp-
fire. Yet he cites or quotes from about four thousand works, most of which
are known to us only by his references. Doubtless Pliny added much
through his own observations. We know how keen was his desire to
investigate, since he lost his life through attempting to approach the crater
of Vesuvius on the occasion of that memorable eruption which buried the
cities of Herculaneum and Pompeii.
Doubtless the wandering life of the soldier had given Pliny abundant
opportunity for personal observation in his favorite fields of botany and
zoology. But the records of his own observations are so intermingled with
knowledge drawn from books that it is difficult to distinguish the one from
the other. Nor does this greatly matter, for whether as closet-student or
field-naturalist, Pliny's trait of mind is essentially that of the compiler. He
was no philosophical thinker, no generalizer, no path-maker in science. He
lived at the close of a great progressive epoch of thought; in one of those
static periods when numberless observers piled up an immense mass of
details which might advantageously be sorted into a kind of encyclopaedia.
Such an encyclopaedia is the so-called Natural History of Pliny. It is a vast
jumble of more or less uncritical statements regarding almost every field of
contemporary knowledge. The descriptions of animals and plants
predominate, but the work as a whole would have been immensely
improved had the compiler shown a more critical spirit. As it is, he seems
rather disposed to quote any interesting citation that he comes across in his
omnivorous readings, shielding himself behind an equivocal "it is said," or
"so and so alleges." A single illustration will suffice to show what manner
of thing is thought worthy of repetition.

"It is asserted," he says, "that if the fish called a sea-star is smeared with
the fox's blood and then nailed to the upper lintel of the door, or to the door
itself, with a copper nail, no noxious spell will be able to obtain admittance,
or, at all events, be productive of any ill effects."
It is easily comprehensible that a work fortified with such practical
details as this should have gained wide popularity. Doubtless the natural
histories of our own day would find readier sale were they to pander to
various superstitions not altogether different from that here suggested. The
man, for example, who believes that to have a black cat cross his path is a
lucky omen would naturally find himself attracted by a book which took
account of this and similar important details of natural history. Perhaps,
therefore, it was its inclusion of absurdities, quite as much as its legitimate
value, that gave vogue to the celebrated work of Pliny. But be that as it may,
the most famous scientist of Rome must be remembered as a popular writer
rather than as an experimental worker. In the history of the promulgation of
scientific knowledge his work is important; in the history of scientific
principles it may virtually be disregarded.
PTOLEMY, THE LAST GREAT ASTRONOMER OF ANTIQUITY
Almost the same thing may be said of Ptolemy, an even more celebrated
writer, who was born not very long after the death of Pliny. The exact dates
of Ptolemy's life are not known, but his recorded observations extend to the
year 151 A.D. He was a working astronomer, and he made at least one
original discovery of some significance—namely, the observation of a
hitherto unrecorded irregularity of the moon's motion, which came to be
spoken of as the moon's evection. This consists of periodical aberrations
from the moon's regular motion in its orbit, which, as we now know, are due
to the gravitation pull of the sun, but which remained unexplained until the
time of Newton. Ptolemy also made original observations as to the motions
of the planets. He is, therefore, entitled to a respectable place as an
observing astronomer; but his chief fame rests on his writings.
His great works have to do with geography and astronomy. In the former
field he makes an advance upon Strabo, citing the latitude of no fewer than
five thousand places. In the field of astronomy, his great service was to have
made known to the world the labors of Hipparchus. Ptolemy has been
accused of taking the star-chart of his great predecessor without due credit,
and indeed it seems difficult to clear him of this charge. Yet it is at least

open to doubt whether he intended any impropriety, inasmuch as he all
along is sedulous in his references to his predecessor. Indeed, his work
might almost be called an exposition of the astronomical doctrines of
Hipparchus. No one pretends that Ptolemy is to be compared with the
Rhodesian observer as an original investigator, but as a popular expounder
his superiority is evidenced in the fact that the writings of Ptolemy became
practically the sole astronomical text-book of the Middle Ages both in the
East and in the West, while the writings of Hipparchus were allowed to
perish.
The most noted of all the writings of Ptolemy is the work which became
famous under the Arabic name of Almagest. This word is curiously derived
from the Greek title (gr h megisth suntazis), "the greatest construction," a
name given the book to distinguish it from a work on astrology in four
books by the same author. For convenience of reference it came to be
spoken of merely as (gr h megisth), from which the Arabs form the title
Tabair al Magisthi, under which title the book was published in the year
827. From this it derived the word Almagest, by which Ptolemy's work
continued to be known among the Arabs, and subsequently among
Europeans when the book again became known in the West. Ptolemy's
book, as has been said, is virtually an elaboration of the doctrines of
Hipparchus. It assumes that the earth is the fixed centre of the solar system,
and that the stars and planets revolve about it in twenty-four hours, the earth
being, of course, spherical. It was not to be expected that Ptolemy should
have adopted the heliocentric idea of Aristarchus. Yet it is much to be
regretted that he failed to do so, since the deference which was accorded his
authority throughout the Middle Ages would doubtless have been extended
in some measure at least to this theory as well, had he championed it.
Contrariwise, his unqualified acceptance of the geocentric doctrine sufficed
to place that doctrine beyond the range of challenge.
The Almagest treats of all manner of astronomical problems, but the
feature of it which gained it widest celebrity was perhaps that which has to
do with eccentrics and epicycles. This theory was, of course, but an
elaboration of the ideas of Hipparchus; but, owing to the celebrity of the
expositor, it has come to be spoken of as the theory of Ptolemy. We have
sufficiently detailed the theory in speaking of Hipparchus. It should be
explained, however, that, with both Hipparchus and Ptolemy, the theory of
epicycles would appear to have been held rather as a working hypothesis

than as a certainty, so far as the actuality of the minor spheres or epicycles
is concerned. That is to say, these astronomers probably did not conceive
either the epicycles or the greater spheres as constituting actual solid
substances. Subsequent generations, however, put this interpretation upon
the theory, conceiving the various spheres as actual crystalline bodies. It is
difficult to imagine just how the various epicycles were supposed to revolve
without interfering with the major spheres, but perhaps this is no greater
difficulty than is presented by the alleged properties of the ether, which
physicists of to-day accept as at least a working hypothesis. We shall see
later on how firmly the conception of concentric crystalline spheres was
held to, and that no real challenge was ever given that theory until the
discovery was made that comets have an orbit that must necessarily
intersect the spheres of the various planets.
Ptolemy's system of geography in eight books, founded on that of
Marinus of Tyre, was scarcely less celebrated throughout the Middle Ages
than the Almagest. It contained little, however, that need concern us here,
being rather an elaboration of the doctrines to which we have already
sufficiently referred. None of Ptolemy's original manuscripts has come
down to us, but there is an alleged fifth-century manuscript attributed to
Agathadamon of Alexandria which has peculiar interest because it contains
a series of twenty-seven elaborately colored maps that are supposed to be
derived from maps drawn up by Ptolemy himself. In these maps the sea is
colored green, the mountains red or dark yellow, and the land white.
Ptolemy assumed that a degree at the equator was 500 stadia instead of 604
stadia in length. We are not informed as to the grounds on which this
assumption was made, but it has been suggested that the error was at least
partially instrumental in leading to one very curious result. "Taking the
parallel of Rhodes," says Donaldson,(5) "he calculated the longitudes from
the Fortunate Islands to Cattigara or the west coast of Borneo at 180
degrees, conceiving this to be one-half the circumference of the globe. The
real distance is only 125 degrees or 127 degrees, so that his measurement is
wrong by one third of the whole, one-sixth for the error in the measurement
of a degree and one-sixth for the errors in measuring the distance
geometrically. These errors, owing to the authority attributed to the
geography of Ptolemy in the Middle Ages, produced a consequence of the
greatest importance. They really led to the discovery of America. For the
design of Columbus to sail from the west of Europe to the east of Asia was

founded on the supposition that the distance was less by one third than it
really was." This view is perhaps a trifle fanciful, since there is nothing to
suggest that the courage of Columbus would have balked at the greater
distance, and since the protests of the sailors, which nearly thwarted his
efforts, were made long before the distance as estimated by Ptolemy had
been covered; nevertheless it is interesting to recall that the great
geographical doctrines, upon which Columbus must chiefly have based his
arguments, had been before the world in an authoritative form practically
unheeded for more than twelve hundred years, awaiting a champion with
courage enough to put them to the test.
GALEN—THE LAST GREAT ALEXANDRIAN
There is one other field of scientific investigation to which we must give
brief attention before leaving the antique world. This is the field of
physiology and medicine. In considering it we shall have to do with the
very last great scientist of the Alexandrian school. This was Claudius
Galenus, commonly known as Galen, a man whose fame was destined to
eclipse that of all other physicians of antiquity except Hippocrates, and
whose doctrines were to have the same force in their field throughout the
Middle Ages that the doctrines of Aristotle had for physical science. But
before we take up Galen's specific labors, it will be well to inquire briefly as
to the state of medical art and science in the Roman world at the time when
the last great physician of antiquity came upon the scene.
The Romans, it would appear, had done little in the way of scientific
discoveries in the field of medicine, but, nevertheless, with their practicality
of mind, they had turned to better account many more of the scientific
discoveries of the Greeks than did the discoverers themselves. The
practising physicians in early Rome were mostly men of Greek origin, who
came to the capital after the overthrow of the Greeks by the Romans. Many
of them were slaves, as earning money by either bodily or mental labor was
considered beneath the dignity of a Roman citizen. The wealthy Romans,
who owned large estates and numerous slaves, were in the habit of
purchasing some of these slave doctors, and thus saving medical fees by
having them attend to the health of their families.
By the beginning of the Christian era medicine as a profession had sadly
degenerated, and in place of a class of physicians who practised medicine
along rational or legitimate lines, in the footsteps of the great Hippocrates,

there appeared great numbers of "specialists," most of them charlatans, who
pretended to possess supernatural insight in the methods of treating certain
forms of disease. These physicians rightly earned the contempt of the better
class of Romans, and were made the object of many attacks by the satirists
of the time. Such specialists travelled about from place to place in much the
same manner as the itinerant "Indian doctors" and "lightning tooth-
extractors" do to-day. Eye-doctors seem to have been particularly
numerous, and these were divided into two classes, eye-surgeons and eye-
doctors proper. The eye-surgeon performed such operations as cauterizing
for ingrowing eyelashes and operating upon growths about the eyes; while
the eye-doctors depended entirely upon salves and lotions. These eye-salves
were frequently stamped with the seal of the physician who compounded
them, something like two hundred of these seals being still in existence.
There were besides these quacks, however, reputable eye-doctors who must
have possessed considerable skill in the treatment of certain ophthalmias.
Among some Roman surgical instruments discovered at Rheims were found
also some drugs employed by ophthalmic surgeons, and an analysis of these
show that they contained, among other ingredients, some that are still
employed in the treatment of certain affections of the eye.
One of the first steps taken in recognition of the services of physicians
was by Julius Caesar, who granted citizenship to all physicians practising in
Rome. This was about fifty years before the Christian era, and from that
time on there was a gradual improvement in the attitude of the Romans
towards the members of the medical profession. As the Romans
degenerated from a race of sturdy warriors and became more and more
depraved physically, the necessity for physicians made itself more evident.
Court physicians, and physicians-in-ordinary, were created by the emperors,
as were also city and district physicians. In the year 133 A.D. Hadrian
granted immunity from taxes and military service to physicians in
recognition of their public services.
The city and district physicians, known as the archiatri populaires, treated
and cared for the poor without remuneration, having a position and salary
fixed by law and paid them semi-annually. These were honorable positions,
and the archiatri were obliged to give instruction in medicine, without pay,
to the poor students. They were allowed to receive fees and donations from
their patients, but not, however, until the danger from the malady was past.

Special laws were enacted to protect them, and any person subjecting them
to an insult was liable to a fine "not exceeding one thousand pounds."
An example of Roman practicality is shown in the method of treating
hemorrhage, as described by Aulus Cornelius Celsus (53 B.C. to 7 A.D.).
Hippocrates and Hippocratic writers treated hemorrhage by application of
cold, pressure, styptics, and sometimes by actual cauterizing; but they knew
nothing of the simple method of stopping a hemorrhage by a ligature tied
around the bleeding vessel. Celsus not only recommended tying the end of
the injured vessel, but describes the method of applying two ligatures
before the artery is divided by the surgeon—a common practice among
surgeons at the present time. The cut is made between these two, and thus
hemorrhage is avoided from either end of the divided vessel.
Another Roman surgeon, Heliodorus, not only describes the use of the
ligature in stopping hemorrhage, but also the practice of torsion—twisting
smaller vessels, which causes their lining membrane to contract in a manner
that produces coagulation and stops hemorrhage. It is remarkable that so
simple and practical a method as the use of the ligature in stopping
hemorrhage could have gone out of use, once it had been discovered; but
during the Middle Ages it was almost entirely lost sight of, and was not
reintroduced until the time of Ambroise Pare, in the sixteenth century.
Even at a very early period the Romans recognized the advantage of
surgical methods on the field of battle. Each soldier was supplied with
bandages, and was probably instructed in applying them, something in the
same manner as is done now in all modern armies. The Romans also made
use of military hospitals and had established a rude but very practical field-
ambulance service. "In every troop or bandon of two or four hundred men,
eight or ten stout fellows were deputed to ride immediately behind the
fighting-line to pick up and rescue the wounded, for which purpose their
saddles had two stirrups on the left side, while they themselves were
provided with water-flasks, and perhaps applied temporary bandages. They
were encouraged by a reward of a piece of gold for each man they rescued.
'Noscomi' were male nurses attached to the military hospitals, but not
inscribed 'on strength' of the legions, and were probably for the most part of
the servile class."(6)
From the time of the early Alexandrians, Herophilus and Erasistratus,
whose work we have already examined, there had been various anatomists

of some importance in the Alexandrian school, though none quite equal to
these earlier workers. The best-known names are those of Celsus (of whom
we have already spoken), who continued the work of anatomical
investigation, and Marinus, who lived during the reign of Nero, and Rufus
of Ephesus. Probably all of these would have been better remembered by
succeeding generations had their efforts not been eclipsed by those of
Galen. This greatest of ancient anatomists was born at Pergamus of Greek
parents. His father, Nicon, was an architect and a man of considerable
ability. Until his fifteenth year the youthful Galen was instructed at home,
chiefly by his father; but after that time he was placed under suitable
teachers for instruction in the philosophical systems in vogue at that period.
Shortly after this, however, the superstitious Nicon, following the
interpretations of a dream, decided that his son should take up the study of
medicine, and placed him under the instruction of several learned
physicians.
Galen was a tireless worker, making long tours into Asia Minor and
Palestine to improve himself in pharmacology, and studying anatomy for
some time at Alexandria. He appears to have been full of the superstitions
of the age, however, and early in his career made an extended tour into
western Asia in search of the chimerical "jet-stone"—a stone possessing the
peculiar qualities of "burning with a bituminous odor and supposed to
possess great potency in curing such diseases as epilepsy, hysteria, and
gout."
By the time he had reached his twenty-eighth year he had perfected his
education in medicine and returned to his home in Pergamus. Even at that
time he had acquired considerable fame as a surgeon, and his fellow-
citizens showed their confidence in his ability by choosing him as surgeon
to the wounded gladiators shortly after his return to his native city. In these
duties his knowledge of anatomy aided him greatly, and he is said to have
healed certain kinds of wounds that had previously baffled the surgeons.
In the time of Galen dissections of the human body were forbidden by
law, and he was obliged to confine himself to dissections of the lower
animals. He had the advantage, however, of the anatomical works of
Herophilus and Erasistratus, and he must have depended upon them in
perfecting his comparison between the anatomy of men and the lower

animals. It is possible that he did make human dissections surreptitiously,
but of this we have no proof.
He was familiar with the complicated structure of the bones of the
cranium. He described the vertebrae clearly, divided them into groups, and
named them after the manner of anatomists of to-day. He was less accurate
in his description of the muscles, although a large number of these were
described by him. Like all anatomists before the time of Harvey, he had a
very erroneous conception of the circulation, although he understood that
the heart was an organ for the propulsion of blood, and he showed that the
arteries of the living animals did not contain air alone, as was taught by
many anatomists. He knew, also, that the heart was made up of layers of
fibres that ran in certain fixed directions—that is, longitudinal, transverse,
and oblique; but he did not recognize the heart as a muscular organ. In
proof of this he pointed out that all muscles require rest, and as the heart did
not rest it could not be composed of muscular tissue.
Many of his physiological experiments were conducted upon scientific
principles. Thus he proved that certain muscles were under the control of
definite sets of nerves by cutting these nerves in living animals, and
observing that the muscles supplied by them were rendered useless. He
pointed out also that nerves have no power in themselves, but merely
conduct impulses to and from the brain and spinal-cord. He turned this
peculiar knowledge to account in the case of a celebrated sophist,
Pausanias, who had been under the treatment of various physicians for a
numbness in the fourth and fifth fingers of his left hand. These physicians
had been treating this condition by applications of poultices to the hand
itself. Galen, being called in consultation, pointed out that the injury was
probably not in the hand itself, but in the ulner nerve, which controls
sensation in the fourth and fifth fingers. Surmising that the nerve must have
been injured in some way, he made careful inquiries of the patient, who
recalled that he had been thrown from his chariot some time before, striking
and injuring his back. Acting upon this information, Galen applied
stimulating remedies to the source of the nerve itself—that is, to the bundle
of nerve-trunks known as the brachial plexus, in the shoulder. To the
surprise and confusion of his fellow-physicians, this method of treatment
proved effective and the patient recovered completely in a short time.

Although the functions of the organs in the chest were not well
understood by Galen, he was well acquainted with their anatomy. He knew
that the lungs were covered by thin membrane, and that the heart was
surrounded by a sac of very similar tissue. He made constant comparisons
also between these organs in different animals, as his dissections were
performed upon beasts ranging in size from a mouse to an elephant. The
minuteness of his observations is shown by the fact that he had noted and
described the ring of bone found in the hearts of certain animals, such as the
horse, although not found in the human heart or in most animals.
His description of the abdominal organs was in general accurate. He had
noted that the abdominal cavity was lined with a peculiar saclike
membrane, the peritoneum, which also surrounded most of the organs
contained in the cavity, and he made special note that this membrane also
enveloped the liver in a peculiar manner. The exactness of the last
observation seems the more wonderful when we reflect that even to-day the
medical, student finds a correct understanding of the position of the folds of
the peritoneum one of the most difficult subjects in anatomy.
As a practical physician he was held in the highest esteem by the
Romans. The Emperor Marcus Aurelius called him to Rome and appointed
him physician-inordinary to his son Commodus, and on special occasions
Marcus Aurelius himself called in Galen as his medical adviser. On one
occasion, the three army surgeons in attendance upon the emperor declared
that he was about to be attacked by a fever. Galen relates how "on special
command I felt his pulse, and finding it quite normal, considering his age
and the time of day, I declared it was no fever but a digestive disorder, due
to the food he had eaten, which must be converted into phlegm before being
excreted. Then the emperor repeated three times, 'That's the very thing,' and
asked what was to be done. I answered that I usually gave a glass of wine
with pepper sprinkled on it, but for you kings we only use the safest
remedies, and it will suffice to apply wool soaked in hot nard ointment
locally. The emperor ordered the wool, wine, etc., to be brought, and I left
the room. His feet were warmed by rubbing with hot hands, and after
drinking the peppered wine, he said to Pitholaus (his son's tutor), 'We have
only one doctor, and that an honest one,' and went on to describe me as the
first of physicians and the only philosopher, for he had tried many before
who were not only lovers of money, but also contentious, ambitious,
envious, and malignant."(7)

It will be seen from this that Galen had a full appreciation of his own
abilities as a physician, but inasmuch as succeeding generations for a
thousand years concurred in the alleged statement made by Marcus Aurelius
as to his ability, he is perhaps excusable for his open avowal of his belief in
his powers. His faith in his accuracy in diagnosis and prognosis was shown
when a colleague once said to him, "I have used the prognostics of
Hippocrates as well as you. Why can I not prognosticate as well as you?"
To this Galen replied, "By God's help I have never been deceived in my
prognosis."(8) It is probable that this statement was made in the heat of
argument, and it is hardly to be supposed that he meant it literally.
His systems of treatment were far in advance of his theories regarding the
functions of organs, causes of disease, etc., and some of them are still first
principles with physicians. Like Hippocrates, he laid great stress on correct
diet, exercise, and reliance upon nature. "Nature is the overseer by whom
health is supplied to the sick," he says. "Nature lends her aid on all sides,
she decides and cures diseases. No one can be saved unless nature conquers
the disease, and no one dies unless nature succumbs."
From the picture thus drawn of Galen as an anatomist and physician, one
might infer that he should rank very high as a scientific exponent of
medicine, even in comparison with modern physicians. There is, however,
another side to the picture. His knowledge of anatomy was certainly very
considerable, but many of his deductions and theories as to the functions of
organs, the cause of diseases, and his methods of treating them, would be
recognized as absurd by a modern school-boy of average intelligence. His
greatness must be judged in comparison with ancient, not with modern,
scientists. He maintained, for example, that respiration and the pulse-beat
were for one and the same purpose—that of the reception of air into the
arteries of the body. To him the act of breathing was for the purpose of
admitting air into the lungs, whence it found its way into the heart, and
from there was distributed throughout the body by means of the arteries.
The skin also played an important part in supplying the body with air, the
pores absorbing the air and distributing it through the arteries. But, as we
know that he was aware of the fact that the arteries also contained blood, he
must have believed that these vessels contained a mixture of the two.
Modern anatomists know that the heart is divided into two approximately
equal parts by an impermeable septum of tough fibres. Yet, Galen, who

dissected the hearts of a vast number of the lower animals according to his
own account, maintained that this septum was permeable, and that the air,
entering one side of the heart from the lungs, passed through it into the
opposite side and was then transferred to the arteries.
He was equally at fault, although perhaps more excusably so, in his
explanation of the action of the nerves. He had rightly pointed out that
nerves were merely connections between the brain and spinal-cord and
distant muscles and organs, and had recognized that there were two kinds of
nerves, but his explanation of the action of these nerves was that "nervous
spirits" were carried to the cavities of the brain by blood-vessels, and from
there transmitted through the body along the nerve-trunks.
In the human skull, overlying the nasal cavity, there are two thin plates of
bone perforated with numerous small apertures. These apertures allow the
passage of numerous nerve-filaments which extend from a group of cells in
the brain to the delicate membranes in the nasal cavity. These perforations
in the bone, therefore, are simply to allow the passage of the nerves. But
Galen gave a very different explanation. He believed that impure "animal
spirits" were carried to the cavities of the brain by the arteries in the neck
and from there were sifted out through these perforated bones, and so
expelled from the body.
He had observed that the skin played an important part in cooling the
body, but he seems to have believed that the heart was equally active in
overheating it. The skin, therefore, absorbed air for the purpose of "cooling
the heart," and this cooling process was aided by the brain, whose
secretions aided also in the cooling process. The heart itself was the seat of
courage; the brain the seat of the rational soul; and the liver the seat of love.
The greatness of Galen's teachings lay in his knowledge of anatomy of
the organs; his weakness was in his interpretations of their functions.
Unfortunately, succeeding generations of physicians for something like a
thousand years rejected the former but clung to the latter, so that the
advances he had made were completely overshadowed by the mistakes of
his teachings.

XI. A RETROSPECTIVE GLANCE AT
CLASSICAL SCIENCE
It is a favorite tenet of the modern historian that history is a continuous
stream. The contention has fullest warrant. Sharp lines of demarcation are
an evidence of man's analytical propensity rather than the work of nature.
Nevertheless it would be absurd to deny that the stream of history presents
an ever-varying current. There are times when it seems to rush rapidly on;
times when it spreads out into a broad—seemingly static—current; times
when its catastrophic changes remind us of nothing but a gigantic cataract.
Rapids and whirlpools, broad estuaries and tumultuous cataracts are indeed
part of the same stream, but they are parts that vary one from another in
their salient features in such a way as to force the mind to classify them as
things apart and give them individual names.
So it is with the stream of history; however strongly we insist on its
continuity we are none the less forced to recognize its periodicity. It may
not be desirable to fix on specific dates as turning-points to the extent that
our predecessors were wont to do. We may not, for example, be disposed to
admit that the Roman Empire came to any such cataclysmic finish as the
year 476 A.D., when cited in connection with the overthrow of the last
Roman Empire of the West, might seem to indicate. But, on the other hand,
no student of the period can fail to realize that a great change came over the
aspect of the historical stream towards the close of the Roman epoch.
The span from Thales to Galen has compassed about eight hundred years
—let us say thirty generations. Throughout this period there is scarcely a
generation that has not produced great scientific thinkers—men who have
put their mark upon the progress of civilization; but we shall see, as we look
forward for a corresponding period, that the ensuing thirty generations
produced scarcely a single scientific thinker of the first rank. Eight hundred
years of intellectual activity—thirty generations of greatness; then eight
hundred years of stasis—thirty generations of mediocrity; such seems to be
the record as viewed in perspective. Doubtless it seemed far different to the
contemporary observer; it is only in reasonable perspective that any scene

can be viewed fairly. But for us, looking back without prejudice across the
stage of years, it seems indisputable that a great epoch came to a close at
about the time when the barbarian nations of Europe began to sweep down
into Greece and Italy. We are forced to feel that we have reached the limits
of progress of what historians are pleased to call the ancient world. For
about eight hundred years Greek thought has been dominant, but in the
ensuing period it is to play a quite subordinate part, except in so far as it
influences the thought of an alien race. As we leave this classical epoch,
then, we may well recapitulate in brief its triumphs. A few words will
suffice to summarize a story the details of which have made up our recent
chapters.
In the field of cosmology, Greek genius has demonstrated that the earth is
spheroidal, that the moon is earthlike in structure and much smaller than our
globe, and that the sun is vastly larger and many times more distant than the
moon. The actual size of the earth and the angle of its axis with the ecliptic
have been measured with approximate accuracy. It has been shown that the
sun and moon present inequalities of motion which may be theoretically
explained by supposing that the earth is not situated precisely at the centre
of their orbits. A system of eccentrics and epicycles has been elaborated
which serves to explain the apparent motions of the heavenly bodies in a
manner that may be called scientific even though it is based, as we now
know, upon a false hypothesis. The true hypothesis, which places the sun at
the centre of the planetary system and postulates the orbital and axial
motions of our earth in explanation of the motions of the heavenly bodies,
has been put forward and ardently championed, but, unfortunately, is not
accepted by the dominant thinkers at the close of our epoch. In this regard,
therefore, a vast revolutionary work remains for the thinkers of a later
period. Moreover, such observations as the precession of the equinoxes and
the moon's evection are as yet unexplained, and measurements of the earth's
size, and of the sun's size and distance, are so crude and imperfect as to be
in one case only an approximation, and in the other an absurdly inadequate
suggestion. But with all these defects, the total achievement of the Greek
astronomers is stupendous. To have clearly grasped the idea that the earth is
round is in itself an achievement that marks off the classical from the
Oriental period as by a great gulf.
In the physical sciences we have seen at least the beginnings of great
things. Dynamics and hydrostatics may now, for the first time, claim a place

among the sciences. Geometry has been perfected and trigonometry has
made a sure beginning. The conception that there are four elementary
substances, earth, water, air, and fire, may not appear a secure foundation
for chemistry, yet it marks at least an attempt in the right direction.
Similarly, the conception that all matter is made up of indivisible particles
and that these have adjusted themselves and are perhaps held in place by a
whirling motion, while it is scarcely more than a scientific dream, is, after
all, a dream of marvellous insight.
In the field of biological science progress has not been so marked, yet the
elaborate garnering of facts regarding anatomy, physiology, and the
zoological sciences is at least a valuable preparation for the generalizations
of a later time.
If with a map before us we glance at the portion of the globe which was
known to the workers of the period now in question, bearing in mind at the
same time what we have learned as to the seat of labors of the various great
scientific thinkers from Thales to Galen, we cannot fail to be struck with a
rather startling fact, intimations of which have been given from time to time
—the fact, namely, that most of the great Greek thinkers did not live in
Greece itself. As our eye falls upon Asia Minor and its outlying islands, we
reflect that here were born such men as Thales, Anaximander, Anaximenes,
Heraclitus, Pythagoras, Anaxagoras, Socrates, Aristarchus, Hipparchus,
Eudoxus, Philolaus, and Galen. From the northern shores of the aegean
came Lucippus, Democritus, and Aristotle. Italy, off to the west, is the home
of Pythagoras and Xenophanes in their later years, and of Parmenides and
Empedocles, Zeno, and Archimedes. Northern Africa can claim, by birth or
by adoption, such names as Euclid, Apollonius of Perga, Herophilus,
Erasistratus, Aristippus, Eratosthenes, Ctesibius, Hero, Strabo, and Ptolemy.
This is but running over the list of great men whose discoveries have
claimed our attention. Were we to extend the list to include a host of
workers of the second rank, we should but emphasize the same fact.
All along we are speaking of Greeks, or, as they call themselves,
Hellenes, and we mean by these words the people whose home was a small
jagged peninsula jutting into the Mediterranean at the southeastern
extremity of Europe. We think of this peninsula as the home of Greek
culture, yet of all the great thinkers we have just named, not one was born
on this peninsula, and perhaps not one in five ever set foot upon it. In point

of fact, one Greek thinker of the very first rank, and one only, was born in
Greece proper; that one, however, was Plato, perhaps the greatest of them
all. With this one brilliant exception (and even he was born of parents who
came from the provinces), all the great thinkers of Greece had their origin at
the circumference rather than the centre of the empire. And if we reflect that
this circumference of the Greek world was in the nature of the case the
widely circling region in which the Greek came in contact with other
nations, we shall see at once that there could be no more striking illustration
in all history than that furnished us here of the value of racial mingling as a
stimulus to intellectual progress.
But there is one other feature of the matter that must not be overlooked.
Racial mingling gives vitality, but to produce the best effect the mingling
must be that of races all of which are at a relatively high plane of
civilization. In Asia Minor the Greek mingled with the Semite, who had the
heritage of centuries of culture; and in Italy with the Umbrians, Oscans, and
Etruscans, who, little as we know of their antecedents, have left us
monuments to testify to their high development. The chief reason why the
racial mingling of a later day did not avail at once to give new life to
Roman thought was that the races which swept down from the north were
barbarians. It was no more possible that they should spring to the heights of
classical culture than it would, for example, be possible in two or three
generations to produce a racer from a stock of draught horses. Evolution
does not proceed by such vaults as this would imply. Celt, Goth, Hun, and
Slav must undergo progressive development for many generations before
the population of northern Europe can catch step with the classical Greek
and prepare to march forward. That, perhaps, is one reason why we come to
a period of stasis or retrogression when the time of classical activity is over.
But, at best, it is only one reason of several.
The influence of the barbarian nations will claim further attention as we
proceed. But now, for the moment, we must turn our eyes in the other
direction and give attention to certain phases of Greek and of Oriental
thought which were destined to play a most important part in the
development of the Western mind—a more important part, indeed, in the
early mediaeval period than that played by those important inductions of
science which have chiefly claimed our attention in recent chapters. The
subject in question is the old familiar one of false inductions or
pseudoscience. In dealing with the early development of thought and with

Oriental science, we had occasion to emphasize the fact that such false
inductions led everywhere to the prevalence of superstition. In dealing with
Greek science, we have largely ignored this subject, confining attention
chiefly to the progressive phases of thought; but it must not be inferred
from this that Greek science, with all its secure inductions, was entirely free
from superstition. On the contrary, the most casual acquaintance with Greek
literature would suffice to show the incorrectness of such a supposition.
True, the great thinkers of Greece were probably freer from this thraldom of
false inductions than any of their predecessors. Even at a very early day
such men as Xenophanes, Empedocles, Anaxagoras, and Plato attained to a
singularly rationalistic conception of the universe.
We saw that "the father of medicine," Hippocrates, banished demonology
and conceived disease as due to natural causes. At a slightly later day the
sophists challenged all knowledge, and Pyrrhonism became a synonym for
scepticism in recognition of the leadership of a master doubter. The entire
school of Alexandrians must have been relatively free from superstition,
else they could not have reasoned with such effective logicality from their
observations of nature. It is almost inconceivable that men like Euclid and
Archimedes, and Aristarchus and Eratosthenes, and Hipparchus and Hero,
could have been the victims of such illusions regarding occult forces of
nature as were constantly postulated by Oriental science. Herophilus and
Erasistratus and Galen would hardly have pursued their anatomical studies
with equanimity had they believed that ghostly apparitions watched over
living and dead alike, and exercised at will a malign influence.
Doubtless the Egyptian of the period considered the work, of the
Ptolemaic anatomists an unspeakable profanation, and, indeed, it was
nothing less than revolutionary—so revolutionary that it could not be
sustained in subsequent generations. We have seen that the great Galen, at
Rome, five centuries after the time of Herophilus, was prohibited from
dissecting the human subject. The fact speaks volumes for the attitude of
the Roman mind towards science. Vast audiences made up of every stratum
of society thronged the amphitheatre, and watched exultingly while man
slew his fellow-man in single or in multiple combat. Shouts of frenzied joy
burst from a hundred thousand throats when the death-stroke was given to a
new victim. The bodies of the slain, by scores, even by hundreds, were
dragged ruthlessly from the arena and hurled into a ditch as contemptuously
as if pity were yet unborn and human life the merest bauble. Yet the same

eyes that witnessed these scenes with ecstatic approval would have been
averted in pious horror had an anatomist dared to approach one of the
mutilated bodies with the scalpel of science. It was sport to see the blade of
the gladiator enter the quivering, living flesh of his fellow-gladiator; it was
joy to see the warm blood spurt forth from the writhing victim while he still
lived; but it were sacrilegious to approach that body with the knife of the
anatomist, once it had ceased to pulsate with life. Life itself was held utterly
in contempt, but about the realm of death hovered the threatening ghosts of
superstition. And such, be it understood, was the attitude of the Roman
populace in the early and the most brilliant epoch of the empire, before the
Western world came under the influence of that Oriental philosophy which
was presently to encompass it.
In this regard the Alexandrian world was, as just intimated, far more
advanced than the Roman, yet even there we must suppose that the leaders
of thought were widely at variance with the popular conceptions. A few
illustrations, drawn from Greek literature at various ages, will suggest the
popular attitude. In the first instance, consider the poems of Homer and of
Hesiod. For these writers, and doubtless for the vast majority of their
readers, not merely of their own but of many subsequent generations, the
world is peopled with a multitude of invisible apparitions, which, under title
of gods, are held to dominate the affairs of man. It is sometimes difficult to
discriminate as to where the Greek imagination drew the line between fact
and allegory; nor need we attempt to analyse the early poetic narratives to
this end. It will better serve our present purpose to cite three or four
instances which illustrate the tangibility of beliefs based upon pseudo-
scientific inductions.
Let us cite, for example, the account which Herodotus gives us of the
actions of the Greeks at Plataea, when their army confronted the remnant of
the army of Xerxes, in the year 479 B.C. Here we see each side hesitating to
attack the other, merely because the oracle had declared that whichever side
struck the first blow would lose the conflict. Even after the Persian soldiers,
who seemingly were a jot less superstitious or a shade more impatient than
their opponents, had begun the attack, we are told that the Greeks dared not
respond at first, though they were falling before the javelins of the enemy,
because, forsooth, the entrails of a fowl did not present an auspicious
appearance. And these were Greeks of the same generation with
Empedocles and Anaxagoras and aeschylus; of the same epoch with

Pericles and Sophocles and Euripides and Phidias. Such was the scientific
status of the average mind—nay, of the best minds—with here and there a
rare exception, in the golden age of Grecian culture.
Were we to follow down the pages of Greek history, we should but repeat
the same story over and over. We should, for example, see Alexander the
Great balked at the banks of the Hyphasis, and forced to turn back because
of inauspicious auguries based as before upon the dissection of a fowl.
Alexander himself, to be sure, would have scorned the augury; had he been
the prey of such petty superstitions he would never have conquered Asia.
We know how he compelled the oracle at Delphi to yield to his wishes; how
he cut the Gordian knot; how he made his dominating personality felt at the
temple of Ammon in Egypt. We know, in a word, that he yielded to
superstitions only in so far as they served his purpose. Left to his own
devices, he would not have consulted an oracle at the banks of the
Hyphasis; or, consulting, would have forced from the oracle a favorable
answer. But his subordinates were mutinous and he had no choice. Suffice it
for our present purpose that the oracle was consulted, and that its answer
turned the conqueror back.
One or two instances from Roman history may complete the picture.
Passing over all those mythical narratives which virtually constitute the
early history of Rome, as preserved to us by such historians as Livy and
Dionysius, we find so logical an historian as Tacitus recording a miraculous
achievement of Vespasian without adverse comment. "During the months
when Vespasian was waiting at Alexandria for the periodical season of the
summer winds, and a safe navigation, many miracles occurred by which the
favor of Heaven and a sort of bias in the powers above towards Vespasian
were manifested." Tacitus then describes in detail the cure of various
maladies by the emperor, and relates that the emperor on visiting a temple
was met there, in the spirit, by a prominent Egyptian who was proved to be
at the same time some eighty miles distant from Alexandria.
It must be admitted that Tacitus, in relating that Vespasian caused the
blind to see and the lame to walk, qualifies his narrative by asserting that
"persons who are present attest the truth of the transaction when there is
nothing to be gained by falsehood." Nor must we overlook the fact that a
similar belief in the power of royalty has persisted almost to our own day.
But no such savor of scepticism attaches to a narrative which Dion Cassius

gives us of an incident in the life of Marcus Aurelius—an incident that has
become famous as the episode of The Thundering Legion. Xiphilinus has
preserved the account of Dion, adding certain picturesque interpretations of
his own. The original narrative, as cited, asserts that during one of the
northern campaigns of Marcus Aurelius, the emperor and his army were
surrounded by the hostile Quadi, who had every advantage of position and
who presently ceased hostilities in the hope that heat and thirst would
deliver their adversaries into their hands without the trouble of further
fighting. "Now," says Dion, "while the Romans, unable either to combat or
to retreat, and reduced to the last extremity by wounds, fatigue, heat, and
thirst, were standing helplessly at their posts, clouds suddenly gathered in
great number and rain descended in floods—certainly not without divine
intervention, since the Egyptian Maege Arnulphis, who was with Marcus
Antoninus, is said to have invoked several genii by the aerial mercury by
enchantment, and thus through them had brought down rain."
Here, it will be observed, a supernatural explanation is given of a natural
phenomenon. But the narrator does not stop with this. If we are to accept
the account of Xiphilinus, Dion brings forward some striking proofs of
divine interference. Xiphilinus gives these proofs in the following
remarkable paragraph:
"Dion adds that when the rain began to fall every soldier lifted his head
towards heaven to receive the water in his mouth; but afterwards others
hold out their shields or their helmets to catch the water for themselves and
for their horses. Being set upon by the barbarians... while occupied in
drinking, they would have been seriously incommoded had not heavy hail
and numerous thunderbolts thrown consternation into the ranks of the
enemy. Fire and water were seen to mingle as they left the heavens. The
fire, however, did not reach the Romans, but if it did by chance touch one of
them it was immediately extinguished, while at the same time the rain,
instead of comforting the barbarians, seemed merely to excite like oil the
fire with which they were being consumed. Some barbarians inflicted
wounds upon themselves as though their blood had power to extinguish
flames, while many rushed over to the side of the Romans, hoping that there
water might save them."
We cannot better complete these illustrations of pagan credulity than by
adding the comment of Xiphilinus himself. That writer was a Christian,

living some generations later than Dion. He never thought of questioning
the facts, but he felt that Dion's interpretation of these facts must not go
unchallenged. As he interprets the matter, it was no pagan magician that
wrought the miracle. He even inclines to the belief that Dion himself was
aware that Christian interference, and not that of an Egyptian, saved the
day. "Dion knew," he declares, "that there existed a legion called The
Thundering Legion, which name was given it for no other reason than for
what came to pass in this war," and that this legion was composed of
soldiers from Militene who were all professed Christians. "During the
battle," continues Xiphilinus, "the chief of the Pretonians, had set at Marcus
Antoninus, who was in great perplexity at the turn events were taking,
representing to him that there was nothing the people called Christians
could not obtain by their prayers, and that among his forces was a troop
composed wholly of followers of that religion. Rejoiced at this news,
Marcus Antoninus demanded of these soldiers that they should pray to their
god, who granted their petition on the instant, sent lightning among the
enemy and consoled the Romans with rain. Struck by this wonderful
success, the emperor honored the Christians in an edict and named their
legion The Thundering. It is even asserted that a letter existed by Marcus
Antoninus on this subject. The pagans well knew that the company was
called The Thunderers, having attested the fact themselves, but they
revealed nothing of the occasion on which the leader received the name."(1)
Peculiar interest attaches to this narrative as illustrating both
credulousness as to matters of fact and pseudo-scientific explanation of
alleged facts. The modern interpreter may suppose that a violent
thunderstorm came up during the course of a battle between the Romans
and the so-called barbarians, and that owing to the local character of the
storm, or a chance discharge of lightning, the barbarians suffered more than
their opponents. We may well question whether the philosophical emperor
himself put any other interpretation than this upon the incident. But, on the
other hand, we need not doubt that the major part of his soldiers would very
readily accept such an explanation as that given by Dion Cassius, just as
most readers of a few centuries later would accept the explanation of
Xiphilinus. It is well to bear this thought in mind in considering the static
period of science upon which we are entering. We shall perhaps best
understand this period, and its seeming retrogressions, if we suppose that
the average man of the Middle Ages was no more credulous, no more

superstitious, than the average Roman of an earlier period or than the
average Greek; though the precise complexion of his credulity had changed
under the influence of Oriental ideas, as we have just seen illustrated by the
narrative of Xiphilinus.

APPENDIX
REFERENCE LIST, NOTES, AND BIBLIOGRAPHIES

CHAPTER I. PREHISTORIC SCIENCE
Length of the Prehistoric Period.—It is of course quite impossible to
reduce the prehistoric period to any definite number of years. There are,
however, numerous bits of evidence that enable an anthropologist to make
rough estimates as to the relative lengths of the different periods into which
prehistoric time is divided. Gabriel de Mortillet, one of the most industrious
students of prehistoric archaeology, ventured to give a tentative estimate as
to the numbers of years involved in each period. He of course claimed for
this nothing more than the value of a scientific guess. It is, however, a guess
based on a very careful study of all data at present available. Mortillet
divides the prehistoric period, as a whole, into four epochs. The first of
these is the preglacial, which he estimates as comprising seventy-eight
thousand years; the second is the glacial, covering one hundred thousand
years; then follows what he terms the Solutreen, which numbers eleven
thousand years; and, finally, the Magdalenien, comprising thirty-three
thousand years. This gives, for the prehistoric period proper, a term of about
two hundred and twenty-two thousand years. Add to this perhaps twelve
thousand years ushering in the civilization of Egypt, and the six thousand
years of stable, sure chronology of the historical period, and we have
something like two hundred and thirty thousand or two hundred and forty
thousand years as the age of man.
"These figures," says Mortillet, "are certainly not exaggerated. It is even
probable that they are below the truth. Constantly new discoveries are being
made that tend to remove farther back the date of man's appearance." We
see, then, according to this estimate, that about a quarter of a million years
have elapsed since man evolved to a state that could properly be called
human. This guess is as good as another, and it may advantageously be kept
in mind, as it will enable us all along to understand better than we might
otherwise be able to do the tremendous force of certain prejudices and
preconceptions which recent man inherited from his prehistoric ancestor.
Ideas which had passed current as unquestioned truths for one hundred
thousand years or so are not easily cast aside.

In going back, in imagination, to the beginning of the prehistoric period,
we must of course reflect, in accordance with modern ideas on the subject,
that there was no year, no millennium even, when it could be said expressly:
"This being was hitherto a primate, he is now a man." The transition period
must have been enormously long, and the changes from generation to
generation, even from century to century, must have been very slight. In
speaking of the extent of the age of man this must be borne in mind: it must
be recalled that, even if the period were not vague for other reasons, the
vagueness of its beginning must make it indeterminate.
Bibliographical Notes.—A great mass of literature has been produced in
recent years dealing with various phases of the history of prehistoric man.
No single work known to the writer deals comprehensively with the
scientific attainments of early man; indeed, the subject is usually ignored,
except where practical phases of the mechanical arts are in question. But of
course any attempt to consider the condition of primitive man talies into
account, by inference at least, his knowledge and attainments. Therefore,
most works on anthropology, ethnology, and primitive culture may be
expected to throw some light on our present subject. Works dealing with the
social and mental conditions of existing savages are also of importance,
since it is now an accepted belief that the ancestors of civilized races
evolved along similar lines and passed through corresponding stages of
nascent culture. Herbert Spencer's Descriptive Sociology presents an
unequalled mass of facts regarding existing primitive races, but,
unfortunately, its inartistic method of arrangement makes it repellent to the
general reader. E. B. Tyler's Primitive Culture and Anthropology; Lord
Avebury's Prehistoric Times, The Origin of Civilization, and The Primitive
Condition of Man; W. Boyd Dawkin's Cave-Hunting and Early Man in
Britain; and Edward Clodd's Childhood of the World and Story of Primitive
Man are deservedly popular. Paul Topinard's Elements d'Anthropologie
Generale is one of the best-known and most comprehensive French works
on the technical phases of anthropology; but Mortillet's Le Prehistorique
has a more popular interest, owing to its chapters on primitive industries,
though this work also contains much that is rather technical. Among
periodicals, the Revue de l'Ecole d'Anthropologie de Paris, published by the
professors, treats of all phases of anthropology, and the American
Anthropologist, edited by F. W. Hodge for the American Anthropological
Association, and intended as "a medium of communication between

students of all branches of anthropology," contains much that is of interest
from the present stand-point. The last-named journal devotes a good deal of
space to Indian languages.

CHAPTER II. EGYPTIAN SCIENCE
1 (p. 34). Sir J. Norman Lockyer, The Dawn of Astronomy; a study of the
temple worship and mythology of the ancient Egyptians, London, 1894.
2 (p. 43). G. Maspero, Histoire Ancie-nne des Peuples de l'Orient
Classique, Paris, 1895. Translated as (1) The Dawn of Civilization, (2) The
Struggle of the Nations, (3) The Passing of the Empires, 3 vols., London
and New York, 1894-1900. Professor Maspero is one of the most famous of
living Orientalists. His most important special studies have to do with
Egyptology, but his writings cover the entire field of Oriental antiquity. He
is a notable stylist, and his works are at once readable and authoritative.
3 (p. 44). Adolf Erman, Life in Ancient Egypt, London, 1894, p. 352.
(Translated from the original German work entitled Aegypten und
aegyptisches Leben in Alterthum, Tilbigen, 1887.) An altogether admirable
work, full of interest for the general reader, though based on the most
erudite studies.
4 (p. 47). Erman, op. cit., pp. 356, 357.
5 (p. 48). Erman, op. cit., p. 357. The work on Egyptian medicine here
referred to is Georg Ebers' edition of an Egyptian document discovered by
the explorer whose name it bears. It remains the most important source of
our knowledge of Egyptian medicine. As mentioned in the text, this
document dates from the eighteenth dynasty—that is to say, from about the
fifteenth or sixteenth century, B.C., a relatively late period of Egyptian
history.
6 (p. 49). Erman, op. cit., p. 357.
7 (p. 50). The History of Herodotus, pp. 85-90. There are numerous
translations of the famous work of the "father of history," one of the most
recent and authoritative being that of G. C. Macaulay, M.A., in two
volumes, Macmillan & Co., London and New York, 1890.
8 (p. 50). The Historical Library of Diodorus the Sicilian, London, 1700.
This most famous of ancient world histories is difficult to obtain in an
English version. The most recently published translation known to the
writer is that of G. Booth, London, 1814.

9 (p. 51). Erman, op. cit., p. 357.
10 (p. 52). The Papyrus Rhind is a sort of mathematical hand-book of the
ancient Egyptians; it was made in the time of the Hyksos Kings (about 2000
B.C.), but is a copy of an older book. It is now preserved in the British
Museum.
The most accessible recent sources of information as to the social
conditions of the ancient Egyptians are the works of Maspero and Erman,
above mentioned; and the various publications of W. M. Flinders Petrie,
The Pyramids and Temples of Gizeh, London, 1883; Tanis I., London,
1885; Tanis H., Nebesheh, and Defe-nnel, London, 1887; Ten Years'
Diggings, London, 1892; Syria and Egypt from the Tel-el-Amar-na Letters,
London, 1898, etc. The various works of Professor Petrie, recording his
explorations from year to year, give the fullest available insight into
Egyptian archaeology.

CHAPTER III. SCIENCE OF BABYLONIA AND
ASSYRIA
1 (p. 57). The Medes. Some difference of opinion exists among historians
as to the exact ethnic relations of the conquerors; the precise date of the fall
of Nineveh is also in doubt.
2 (p. 57). Darius. The familiar Hebrew narrative ascribes the first Persian
conquest of Babylon to Darius, but inscriptions of Cyrus and of Nabonidus,
the Babylonian king, make it certain that Cyrus was the real conqueror.
These inscriptions are preserved on cylinders of baked clay, of the type
made familiar by the excavation of the past fifty years, and they are
invaluable historical documents.
3 (p. 58). Berosus. The fragments of Berosus have been translated by L.
P. Cory, and included in his Ancient Fragments of Phenician, Chaldean,
Egyptian, and Other Writers, London, 1826, second edition, 1832.
4 (p. 58). Chaldean learning. Recent writers reserve the name Chaldean
for the later period of Babylonian history—the time when the Greeks came
in contact with the Mesopotamians—in contradistinction to the earlier
periods which are revealed to us by the archaeological records.
5 (p. 59) King Sargon of Agade. The date given for this early king must
not be accepted as absolute; but it is probably approximately correct.
6 (p. 59). Nippur. See the account of the early expeditions as recorded by
the director, Dr. John P. Peters, Nippur, or explorations and adventures, etc.,
New York and London, 1897.
7 (p. 62). Fritz Hommel, Geschichte Babyloniens und Assyriens, Berlin,
1885.
8 (p. 63). R. Campbell Thompson, Reports of the Magicians and
Astrologers of Nineveh and Babylon, London, 1900, p. xix.
9 (p. 64). George Smith, The Assyrian Canon, p. 21.
10 (p. 64). Thompson, op. cit., p. xix.
11 (p. 65). Thompson, op. cit., p. 2.

12 (p. 67). Thompson, op. cit., p. xvi.
13 (p. 68). Sextus Empiricus, author of Adversus Mathematicos, lived
about 200 A.D.
14 (p. 68). R. Campbell Thompson, op. cit., p. xxiv.
15 (p. 72). Records of the Past (editor, Samuel Birch), Vol. III., p. 139.
16 (p. 72). Ibid., Vol. V., p. 16.
17 (p. 72). Quoted in Records of the Past, Vol. III., p. 143, from the
Translations of the Society of Biblical Archeology, vol. II., p. 58.
18 (p. 73). Records of the Past, vol. L, p. 131.
19 (p. 73). Ibid., vol. V., p. 171.
20 (p. 74). Ibid., vol. V., p. 169.
21 (p. 74). Joachim Menant, La Bibliotheque du Palais de Ninive, Paris,
1880.
22 (p. 76). Code of Khamurabi. This famous inscription is on a block of
black diorite nearly eight feet in height. It was discovered at Susa by the
French expedition under M. de Morgan, in December, 1902. We quote the
translation given in The Historians' History of the World, edited by Henry
Smith Williams, London and New York, 1904, Vol. I, p. 510.
23 (p. 77). The Historical Library of Diodorus Siculus, p. 519.
24 (p. 82). George S. Goodspeed, Ph.D., History of the Babylonians and
Assyrians, New York, 1902.
25 (p. 82). George Rawlinson, Great Oriental Monarchies, (second
edition, London, 1871), Vol. III., pp. 75 ff.
Of the books mentioned above, that of Hommel is particularly full in
reference to culture development; Goodspeed's small volume gives an
excellent condensed account; the original documents as translated in the
various volumes of Records of the Past are full of interest; and Menant's
little book is altogether admirable. The work of excavation is still going on
in old Babylonia, and newly discovered texts add from time to time to our
knowledge, but A. H. Layard's Nineveh and its Remains (London, 1849)
still has importance as a record of the most important early discoveries. The
general histories of Antiquity of Duncker, Lenormant, Maspero, and Meyer
give full treatment of Babylonian and Assyrian development. Special
histories of Babylonia and Assyria, in addition to these named above, are

Tiele's Babylonisch-Assyrische Geschichte (Zwei Tiele, Gotha, 1886-1888);
Winckler's Geschichte Babyloniens und Assyriens (Berlin, 1885-1888), and
Rogers' History of Babylonia and Assyria, New York and London, 1900, the
last of which, however, deals almost exclusively with political history.
Certain phases of science, particularly with reference to chronology and
cosmology, are treated by Edward Meyer (Geschichte des Alterthum, Vol.
I., Stuttgart, 1884), and by P. Jensen (Die Kosmologie der Babylonier,
Strassburg, 1890), but no comprehensive specific treatment of the subject in
its entirety has yet been attempted.

CHAPTER IV. THE DEVELOPMENT OF THE
ALPHABET
1 (p. 87). Vicomte E. de Rouge, Memoire sur l'Origine Egyptienne de
l'Alphabet Phinicien, Paris, 1874.
2 (p. 88). See the various publications of Mr. Arthur Evans.
3 (p. 80). Aztec and Maya writing. These pictographs are still in the main
undecipherable, and opinions differ as to the exact stage of development
which they represent.
4 (p. 90). E. A. Wallace Budge's First Steps in Egyptian, London, 1895, is
an excellent elementary work on the Egyptian writing. Professor Erman's
Egyptian Grammar, London, 1894, is the work of perhaps the foremost
living Egyptologist.
5 (P. 93). Extant examples of Babylonian and Assyrian writing give
opportunity to compare earlier and later systems, so the fact of evolution
from the pictorial to the phonetic system rests on something more than mere
theory.
6 (p. 96). Friedrich Delitzsch, Assyrischc Lesestucke mit grammatischen
Tabellen und vollstdndigem Glossar einfiihrung in die assyrische und
babylonische Keilschrift-litteratur bis hinauf zu Hammurabi, Leipzig, 1900.
7 (p. 97). It does not appear that the Babylonians thcmselves ever gave
up the old system of writing, so long as they retained political autonomy.
8 (p. 101). See Isaac Taylor's History of the Alphabet; an Account of the
origin and Development of Letters, new edition, 2 vols., London, 1899.
For facsimiles of the various scripts, see Henry Smith Williams' History
of the Art Of Writing, 4 vols, New York and London, 1902-1903.

CHAPTER V. THE BEGINNINGS OF GREEK
SCIENCE
1 (p. III). Anaximander, as recorded by Plutarch, vol. VIII-. See Arthur
Fairbanks'First Philosophers of Greece: an Edition and Translation of the
Remaining Fragments of the Pre-Socratic Philosophers, together with a
Translation of the more Important Accounts of their Opinions Contained in
the Early Epitomcs of their Works, London, 1898. This highly scholarly and
extremely useful book contains the Greek text as well as translations.

CHAPTER VI. THE EARLY GREEK
PHILOSOPHERS IN ITALY
1 (p. 117). George Henry Lewes, A Biographical History of Philosophy
from its Origin in Greece down to the Present Day, enlarged edition, New
York, 1888, p. 17.
2 (p. 121). Diogenes Laertius, The Lives and Opinions of Eminent
Philosophers, C. D. Yonge's translation, London, 1853, VIII., p. 153.
3 (p. 121). Alexander, Successions of Philosophers.
4 (p. 122). "All over its centre." Presumably this is intended to refer to
the entire equatorial region.
5 (p. 125). Laertius, op. cit., pp. 348-351.
6 (p. 128). Arthur Fairbanks, The First Philosophers of Greece London,
1898, pp. 67-717.
7 (p. 129). Ibid., p. 838.
8 (p. 130). Ibid., p. 109.
9 (p. 130). Heinrich Ritter, The History of Ancient Philosophy, translated
from the German by A. J. W. Morrison, 4 vols., London, 1838, vol, I., p.
463.
10 (p. 131). Ibid., p. 465.
11 (p. 132). George Henry Lewes, op. cit., p. 81.
12 (p. 135). Fairbanks, op. cit., p. 201.
13 (p. 136). Ibid., P. 234.
14 (p. 137). Ibid., p. 189.
15 (p. 137). Ibid., P. 220.
16 (p. 138). Ibid., p. 189.
17 (p. 138). Ibid., p. 191.

CHAPTER VII. GREEK SCIENCE IN THE
EARLY ATTIC PERIOD
1 (p. 150). Theodor Gomperz, Greek Thinkers: a History of Ancient
Philosophy (translated from the German by Laurie Magnes), New York, 190
1, pp. 220, 221.
2 (p. 153). Aristotle's Treatise on Respiration, ch. ii.
3 (p. 159). Fairbanks' translation of the fragments of Anaxagoras, in The
First Philosophers of Greece, pp. 239-243.

CHAPTER VIII. POST-SOCRATIC SCIENCE
AT ATHENS
1 (p. 180). Alfred William Bern, The Philosophy of Greece Considered in
Relation to the Character and History of its People, London, 1898, p. 186.
2 (p. 183). Aristotle, quoted in William Whewell's History of the
Inductive Sciences (second edition, London, 1847), Vol. II., p. 161.

CHAPTER IX. GREEK SCIENCE OF THE
ALEXANDRIAN OR HELLENISTIC PERIOD
1 (p. 195). Tertullian's Apologeticus.

2 (p. 205). We quote the quaint old translation of North, printed in 1657.

CHAPTER X. SCIENCE OF THE ROMAN
PERIOD
1 (p. 258). The Geography of Strabo, translated by H. C. Hamilton and
W. Falconer, 3 vols., London, 1857, Vol. I, pp. 19, 20.
2 (p. 260). Ibid., p. 154.
3 (p. 263). Ibid., pp. 169, 170.
4 (p. 264) Ibid., pp. 166, 167.
5 (p. 271). K. 0. Miller and John W. Donaldson, The History of the
Literature of Greece, 3 vols., London, Vol. III., p. 268.
6 (p. 276). E. T. Withington, Medical History fron., the Earliest Times,
London, 1894, p. 118.
7 (p. 281). Ibid.
8 (p. 281). Johann Hermann Bass, History of Medicine, New York, 1889.

CHAPTER XI. A RETROSPECTIVE GLANCE
AT CLASSICAL SCIENCE
(p. 298). Dion Cassius, as preserved by Xiphilinus. Our extract is quoted
from the translation given in The Historians' History of the World (edited by
Henry Smith Williams), 25 vols., London and New York, 1904, Vol. VI., p.
297 ff.
(For further bibliographical notes, the reader is referred to the Appendix
of volume V.)

TABLE OF CONTENTS

FOR THE FIVE VOLUMES

BOOK I
I. PREHISTORIC SCIENCE
II. EGYPTIAN SCIENCE

III. SCIENCE OF BABYLONIA AND ASSYRIA
IV. THE DEVELOPMENT OF THE ALPHABET
V. THE BEGINNINGS OF GREEK SCIENCE
VI. THE EARLY GREEK PHILOSOPHERS IN ITALY
VII. GREEK SCIENCE IN THE EARLY ATTIC PERIOD
VIII. POST-SOCRATIC SCIENCE AT ATHENS—PLATO,
ARISTOTLE, AND THEOPHRASTUS
IX. GREEK SCIENCE OF THE ALEXANDRIAN OR HELLENISTIC
PERIOD
X. SCIENCE OF THE ROMAN PERIOD
XI. A RETROSPECTIVE GLANCE AT CLASSICAL SCIENCE

BOOK II. THE BEGINNINGS OF MODERN SCIENCE
I. SCIENCE IN THE DARK AGE
II. MEDIAEVAL SCIENCE AMONG THE ARABIANS
III. MEDIAEVAL SCIENCE IN THE WEST
IV. THE NEW COSMOLOGY—COPERNICUS TO KEPLER AND
GALILEO
V. GALILEO AND THE NEW PHYSICS
VI. TWO PSEUDO-SCIENCES—ALCHEMY AND ASTROLOGY
VII. FROM PARACELSUS TO HARVEY

VIII. MEDICINE IN THE SIXTEENTH AND SEVENTEENTH
CENTURIES
IX. PHILOSOPHER-SCIENTISTS AND NEW INSTITUTIONS OF
LEARNING
X. THE SUCCESSORS OF GALILEO IN PHYSICAL SCIENCE
XI. NEWTON AND THE COMPOSITION OF LIGHT
XII. NEWTON AND THE LAW OF GRAVITATION
XIII. INSTRUMENTS OF PRECISION IN THE AGE OF NEWTON
XIV. PROGRESS IN ELECTRICITY FROM GILBERT AND VON
GUERICKE TO FRANKLIN
XV. NATURAL HISTORY TO THE TIME OF LINNAEUS

BOOK III. MODERN DEVELOPMENT OF THE PHYSICAL
SCIENCES
I. THE SUCCESSORS OF NEWTON IN ASTRONOMY
II. THE PROGRESS OF MODERN ASTRONOMY
III. THE NEW SCIENCE OF PALEONTOLOGY
IV. THE ORIGIN AND DEVELOPMENT OF MODERN GEOLOGY
V. THE NEW SCIENCE OF METEOROLOGY
VI. MODERN THEORIES OF HEAT AND LIGHT
VII. THE MODERN DEVELOPMENT OF ELECTRICITY AND
MAGNETISM

VIII. THE CONSERVATION OF ENERGY
IX. THE ETHER AND PONDERABLE MATTER

BOOK IV. MODERN DEVELOPMENT OF THE CHEMICAL AND
BIOLOGICAL SCIENCES
I. THE PHLOGISTON THEORY IN CHEMISTRY
II. THE BEGINNINGS OF MODERN CHEMISTRY
III. CHEMISTRY SINCE THE TIME OF DALTON
IV. ANATOMY AND PHYSIOLOGY IN THE EIGHTEENTH
CENTURY
V. ANATOMY AND PHYSIOLOGY IN THE NINETEENTH
CENTURY
VI. THEORIES OF ORGANIC EVOLUTION
VII. EIGHTEENTH-CENTURY MEDICINE
VIII. NINETEENTH-CENTURY MEDICINE
IX. THE NEW SCIENCE OF EXPERIMENTAL PSYCHOLOGY
X. THE NEW SCIENCE OF ORIENTAL ARCHAEOLOGY

BOOK V. ASPECTS OF RECENT SCIENCE

I. THE BRITISH MUSEUM
II. THE ROYAL SOCIETY OF LONDON FOR IMPROVING
NATURAL KNOWLEDGE
III. THE ROYAL INSTITUTION AND THE LOW-TEMPERATURE
RESEARCHES
IV. SOME PHYSICAL LABORATORIES AND PHYSICAL
PROBLEMS
V. THE MARINE BIOLOGICAL LABORATORY AT NAPLES
VI. ERNST HAECKEL AND THE NEW ZOOLOGY
VII. SOME MEDICAL LABORATORIES AND MEDICAL
PROBLEMS
VII. SOME UNSOLVED SCIENTIFIC PROBLEMS
IX. RETROSPECT AND PROSPECT

*** END OF THE PROJECT GUTENBERG EBOOK A HISTORY OF
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