a history of science-1-第20章

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e　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　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　friendin　a　sense　the　teacherof　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　w