a history of science-1-第27章
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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 partsan 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 i
