a history of science-1-第24节

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edocles　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　dayunless；　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　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