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A History of Science, Volume 1
H >> Henry Smith Williams >> A History of Science, Volume 1 Pages: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20
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 .
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."
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