第3章

Fromthesefactswemaysufficientlyperceivethemeaningofthe

ancientswhosaidtheelementsofnatureweremorethanone；butthere

aresomewhospokeoftheuniverseasifitwereoneentity，though

theywerenotallalikeeitherintheexcellenceoftheirstatementor

initsconformitytothefactsofnature。Thediscussionofthemisin

nowayappropriatetoourpresentinvestigationofcauses，for。they

donot，likesomeofthenaturalphilosophers，assumebeingtobe

oneandyetgenerateitoutoftheoneasoutofmatter，butthey

speakinanotherway；thoseothersaddchange，sincetheygeneratethe

universe，butthesethinkerssaytheuniverseisunchangeable。Yet

thismuchisgermanetothepresentinquiry:Parmenidesseemsto

fastenonthatwhichisoneindefinition，Melissusonthatwhichis

oneinmatter，forwhichreasontheformersaysthatitislimited，

thelatterthatitisunlimited；whileXenophanes，thefirstof

thesepartisansoftheOne(forParmenidesissaidtohavebeenhis

pupil)，gavenoclearstatement，nordoesheseemtohavegrasped

thenatureofeitherofthesecauses，butwithreferencetothe

wholematerialuniversehesaystheOneisGod。Nowthesethinkers，as

wesaid，mustbeneglectedforthepurposesofthepresentinquiry-two

ofthementirely，asbeingalittletoonaive，viz。Xenophanesand

Melissus；butParmenidesseemsinplacestospeakwithmoreinsight。

For，claimingthat，besidestheexistent，nothingnon-existentexists，

hethinksthatofnecessityonethingexists，viz。theexistentand

nothingelse(onthiswehavespokenmoreclearlyinourworkon

nature)，butbeingforcedtofollowtheobservedfacts，and

supposingtheexistenceofthatwhichisoneindefinition，butmore

thanoneaccordingtooursensations，henowpositstwocausesandtwo

principles，callingthemhotandcold，i。e。fireandearth；andof

theseherangesthehotwiththeexistent，andtheotherwiththe

non-existent。

Fromwhathasbeensaid，then，andfromthewisemenwhohave

nowsatincouncilwithus，wehavegotthusmuch-ontheonehandfrom

theearliestphilosophers，whoregardthefirstprincipleascorporeal

(forwaterandfireandsuchthingsarebodies)，andofwhomsome

supposethatthereisonecorporealprinciple，othersthatthereare

morethanone，butbothputtheseundertheheadofmatter；andonthe

otherhandfromsomewhopositboththiscauseandbesidesthisthe

sourceofmovement，whichwehavegotfromsomeassingleandfrom

othersastwofold。

DowntotheItalianschool，then，andapartfromit，

philosophershavetreatedthesesubjectsratherobscurely，except

that，aswesaid，theyhaveinfactusedtwokindsofcause，andone

ofthese-thesourceofmovement-sometreatasoneandothersastwo。

ButthePythagoreanshavesaidinthesamewaythattherearetwo

principles，butaddedthismuch，whichispeculiartothem，that

theythoughtthatfinitudeandinfinitywerenotattributesofcertain

otherthings，e。g。offireorearthoranythingelseofthiskind，but

thatinfinityitselfandunityitselfwerethesubstanceofthethings

ofwhichtheyarepredicated。Thisiswhynumberwasthesubstance

ofallthings。Onthissubject，then，theyexpressedthemselves

thus；andregardingthequestionofessencetheybegantomake

statementsanddefinitions，buttreatedthemattertoosimply。For

theybothdefinedsuperficiallyandthoughtthatthefirstsubject

ofwhichagivendefinitionwaspredicablewasthesubstanceofthe

thingdefined，asifonesupposedthat’double’and’2’werethesame，

because2isthefirstthingofwhich’double’ispredicable。But

surelytobedoubleandtobe2arenotthesame；iftheyare，one

thingwillbemany-aconsequencewhichtheyactuallydrew。Fromthe

earlierphilosophers，then，andfromtheirsuccessorswecanlearn

thusmuch。

AfterthesystemswehavenamedcamethephilosophyofPlato，

whichinmostrespectsfollowedthesethinkers，buthad

pecullaritiesthatdistinguisheditfromthephilosophyofthe

Italians。For，havinginhisyouthfirstbecomefamiliarwithCratylus

andwiththeHeracliteandoctrines(thatallsensiblethingsare

everinastateoffluxandthereisnoknowledgeaboutthem)，these

viewsheheldeveninlateryears。Socrates，however，wasbusying

himselfaboutethicalmattersandneglectingtheworldofnatureas

awholebutseekingtheuniversalintheseethicalmatters，and

fixedthoughtforthefirsttimeondefinitions；Platoacceptedhis

teaching，butheldthattheproblemappliednottosensiblethingsbut

toentitiesofanotherkind-forthisreason，thatthecommon

definitioncouldnotbeadefinitionofanysensiblething，asthey

werealwayschanging。Thingsofthisothersort，then，hecalled

Ideas，andsensiblethings，hesaid，wereallnamedafterthese，and

invirtueofarelationtothese；forthemanyexistedby

participationintheIdeasthathavethesamenameasthey。Onlythe

name’participation’wasnew；forthePythagoreanssaythatthings

existby’imitation’ofnumbers，andPlatosaystheyexistby

participation，changingthename。Butwhattheparticipationorthe

imitationoftheFormscouldbetheyleftanopenquestion。

Further，besidessensiblethingsandFormshesaystherearethe

objectsofmathematics，whichoccupyanintermediateposition，

differingfromsensiblethingsinbeingeternalandunchangeable，from

Formsinthattherearemanyalike，whiletheFormitselfisineach

caseunique。

SincetheFormswerethecausesofallotherthings，hethought

theirelementsweretheelementsofallthings。Asmatter，thegreat

andthesmallwereprinciples；asessentialreality，theOne；forfrom

thegreatandthesmall，byparticipationintheOne，comethe

Numbers。

ButheagreedwiththePythagoreansinsayingthattheOneis

substanceandnotapredicateofsomethingelse；andinsayingthat

theNumbersarethecausesoftherealityofotherthingsheagreed

withthem；butpositingadyadandconstructingtheinfiniteoutof

greatandsmall，insteadoftreatingtheinfiniteasone，is

peculiartohim；andsoishisviewthattheNumbersexistapart

fromsensiblethings，whiletheysaythatthethingsthemselvesare

Numbers，anddonotplacetheobjectsofmathematicsbetweenFormsand

sensiblethings。HisdivergencefromthePythagoreansinmakingthe

OneandtheNumbersseparatefromthings，andhisintroductionof

theForms，wereduetohisinquiriesintheregionofdefinitions(for

theearlierthinkershadnotinctureofdialectic)，andhismakingthe

otherentitybesidestheOneadyadwasduetothebeliefthatthe

numbers，exceptthosewhichwereprime，couldbeneatlyproducedout

ofthedyadasoutofsomeplasticmaterial。Yetwhathappensisthe

contrary；thetheoryisnotareasonableone。Fortheymakemany

thingsoutofthematter，andtheformgeneratesonlyonce，butwhat

weobserveisthatonetableismadefromonematter，whiletheman

whoappliestheform，thoughheisone，makesmanytables。Andthe

relationofthemaletothefemaleissimilar；forthelatteris

impregnatedbyonecopulation，butthemaleimpregnatesmany

females；yettheseareanaloguesofthosefirstprinciples。

Plato，then，declaredhimselfthusonthepointsinquestion；it

isevidentfromwhathasbeensaidthathehasusedonlytwocauses，

thatoftheessenceandthematerialcause(fortheFormsarethe

causesoftheessenceofallotherthings，andtheOneisthecauseof

theessenceoftheForms)；anditisevidentwhattheunderlying

matteris，ofwhichtheFormsarepredicatedinthecaseofsensible

things，andtheOneinthecaseofForms，viz。thatthisisadyad，

thegreatandthesmall。Further，hehasassignedthecauseofgood

andthatofeviltotheelements，onetoeachofthetwo，aswesay

someofhispredecessorssoughttodo，e。g。EmpedoclesandAnaxagoras。

Ourreviewofthosewhohavespokenaboutfirstprinciplesand

realityandofthewayinwhichtheyhavespoken，hasbeenconciseand

summary；butyetwehavelearntthismuchfromthem，thatofthosewho

speakabout’principle’and’cause’noonehasmentionedanyprinciple

exceptthosewhichhavebeendistinguishedinourworkonnature，

butallevidentlyhavesomeinklingofthem，thoughonlyvaguely。

Forsomespeakofthefirstprincipleasmatter，whetherthey

supposeoneormorefirstprinciples，andwhethertheysupposethisto

beabodyortobeincorporeal；e。g。Platospokeofthegreatand

thesmall，theItaliansoftheinfinite，Empedoclesoffire，earth，

water，andair，Anaxagorasoftheinfinityofthingscomposedof

similarparts。These，then，haveallhadanotionofthiskindof

cause，andsohaveallwhospeakofairorfireorwater，orsomething

denserthanfireandrarerthanair；forsomehavesaidtheprime

elementisofthiskind。

Thesethinkersgraspedthiscauseonly；butcertainothershave

mentionedthesourceofmovement，e。g。thosewhomakefriendshipand

strife，orreason，orlove，aprinciple。

Theessence，i。e。thesubstantialreality，noonehasexpressed

distinctly。ItishintedatchieflybythosewhobelieveintheForms；

fortheydonotsupposeeitherthattheFormsarethematterof

sensiblethings，andtheOnethematteroftheForms，orthattheyare

thesourceofmovement(fortheysaythesearecausesratherof

immobilityandofbeingatrest)，buttheyfurnishtheFormsasthe

essenceofeveryotherthing，andtheOneastheessenceoftheForms。

Thatforwhosesakeactionsandchangesandmovementstake

place，theyasserttobeacauseinaway，butnotinthisway，i。e。

notinthewayinwhichitisitsnaturetobeacause。Forthose

whospeakofreasonorfriendshipclassthesecausesasgoods；theydo

notspeak，however，asifanythingthatexistseitherexistedor

cameintobeingforthesakeofthese，butasifmovementsstarted

fromthese。InthesamewaythosewhosaytheOneortheexistentis

thegood，saythatitisthecauseofsubstance，butnotthat

substanceeitherisorcomestobeforthesakeofthis。Therefore

itturnsoutthatinasensetheybothsayanddonotsaythegood

isacause；fortheydonotcallitacausequagoodbutonly

incidentally。

Allthesethinkersthen，astheycannotpitchonanothercause，

seemtotestifythatwehavedeterminedrightlybothhowmanyandof

whatsortthecausesare。Besidesthisitisplainthatwhenthe

causesarebeinglookedfor，eitherallfourmustbesoughtthusor

theymustbesoughtinoneofthesefourways。Letusnextdiscussthe

possibledifficultieswithregardtothewayinwhicheachofthese

thinkershasspoken，andwithregardtohissituationrelativelyto

thefirstprinciples。