第5章

Again，itwouldseemimpossiblethatthesubstanceandthatof

whichitisthesubstanceshouldexistapart；how，therefore，could

theIdeas，beingthesubstancesofthings，existapart？InthePhaedo’

thecaseisstatedinthisway-thattheFormsarecausesbothofbeing

andofbecoming；yetwhentheFormsexist，stillthethingsthatshare

inthemdonotcomeintobeing，unlessthereissomethingtooriginate

movement；andmanyotherthingscomeintobeing(e。g。ahouseora

ring)ofwhichwesaytherearenoForms。Clearly，therefore，eventhe

otherthingscanbothbeandcomeintobeingowingtosuchcausesas

producethethingsjustmentioned。

Again，iftheFormsarenumbers，howcantheybecauses？Isit

becauseexistingthingsareothernumbers，e。g。onenumberisman，

anotherisSocrates，anotherCallias？Whythenaretheonesetof

numberscausesoftheotherset？Itwillnotmakeanydifference

eveniftheformerareeternalandthelatterarenot。Butifitis

becausethingsinthissensibleworld(e。g。harmony)areratiosof

numbers，evidentlythethingsbetweenwhichtheyareratiosaresome

oneclassofthings。If，then，this——thematter——issomedefinite

thing，evidentlythenumbersthemselvestoowillberatiosof

somethingtosomethingelse。E。g。ifCalliasisanumericalratio

betweenfireandearthandwaterandair，hisIdeaalsowillbea

numberofcertainotherunderlyingthings；andmanhimself，whetherit

isanumberinasenseornot，willstillbeanumericalratioof

certainthingsandnotanumberproper，norwillitbeaofnumber

merelybecauseitisanumericalratio。

Again，frommanynumbersonenumberisproduced，buthowcanone

FormcomefrommanyForms？Andifthenumbercomesnotfromthemany

numbersthemselvesbutfromtheunitsinthem，e。g。in10，000，how

isitwiththeunits？Iftheyarespecificallyalike，numerous

absurditieswillfollow，andalsoiftheyarenotalike(neitherthe

unitsinonenumberbeingthemselveslikeoneanothernorthosein

othernumbersbeingallliketoall)；forinwhatwilltheydiffer，as

theyarewithoutquality？Thisisnotaplausibleview，norisit

consistentwithourthoughtonthematter。

Further，theymustsetupasecondkindofnumber(withwhich

arithmeticdeals)，andalltheobjectswhicharecalled’intermediate’

bysomethinkers；andhowdotheseexistorfromwhatprinciplesdo

theyproceed？Orwhymusttheybeintermediatebetweenthethingsin

thissensibleworldandthethings-themselves？

Further，theunitsinmusteachcomefromapriorbutthisis

impossible。

Further，whyisanumber，whentakenalltogether，one？

Again，besideswhathasbeensaid，iftheunitsarediversethe

Platonistsshouldhavespokenlikethosewhosaytherearefour，or

two，elements；foreachofthesethinkersgivesthenameofelement

nottothatwhichiscommon，e。g。tobody，buttofireandearth，

whetherthereissomethingcommontothem，viz。body，ornot。Butin

factthePlatonistsspeakasiftheOnewerehomogeneouslikefire

orwater；andifthisisso，thenumberswillnotbesubstances。

Evidently，ifthereisaOneitselfandthisisafirstprinciple，

’one’isbeingusedinmorethanonesense；forotherwisethetheory

isimpossible。

Whenwewishtoreducesubstancestotheirprinciples，westate

thatlinescomefromtheshortandlong(i。e。fromakindofsmalland

great)，andtheplanefromthebroadandnarrow，andbodyfromthe

deepandshallow。Yethowthencaneithertheplanecontainaline，or

thesolidalineoraplane？Forthebroadandnarrowisadifferent

classfromthedeepandshallow。Therefore，justasnumberisnot

presentinthese，becausethemanyandfewaredifferentfromthese，

evidentlynootherofthehigherclasseswillbepresentinthelower。

Butagainthebroadisnotagenuswhichincludesthedeep，forthen

thesolidwouldhavebeenaspeciesofplane。Further，fromwhat

principlewillthepresenceofthepointsinthelinebederived？

Platoevenusedtoobjecttothisclassofthingsasbeinga

geometricalfiction。Hegavethenameofprincipleoftheline-and

thisheoftenposited-totheindivisiblelines。Yetthesemusthave

alimit；thereforetheargumentfromwhichtheexistenceoftheline

followsprovesalsotheexistenceofthepoint。

Ingeneral，thoughphilosophyseeksthecauseofperceptible

things，wehavegiventhisup(forwesaynothingofthecausefrom

whichchangetakesitsstart)，butwhilewefancywearestatingthe

substanceofperceptiblethings，weasserttheexistenceofasecond

classofsubstances，whileouraccountofthewayinwhichtheyare

thesubstancesofperceptiblethingsisemptytalk；for’sharing’，

aswesaidbefore，meansnothing。

NorhavetheFormsanyconnexionwithwhatweseetobethe

causeinthecaseofthearts，thatforwhosesakebothallmindand

thewholeofnatureareoperative，-withthiscausewhichweassert

tobeoneofthefirstprinciples；butmathematicshascometobe

identicalwithphilosophyformodernthinkers，thoughtheysaythatit

shouldbestudiedforthesakeofotherthings。Further，onemight

supposethatthesubstancewhichaccordingtothemunderliesasmatter

istoomathematical，andisapredicateanddifferentiaofthe

substance，ie。ofthematter，ratherthanmatteritself；i。e。the

greatandthesmallareliketherareandthedensewhichthephysical

philosophersspeakof，callingthesetheprimarydifferentiaeofthe

substratum；fortheseareakindofexcessanddefect。Andregarding

movement，ifthegreatandthesmallaretohemovement，evidentlythe

Formswillbemoved；butiftheyarenottobemovement，whencedid

movementcome？Thewholestudyofnaturehasbeenannihilated。

Andwhatisthoughttobeeasy-toshowthatallthingsare

one-isnotdone；forwhatisprovedbythemethodofsettingout

instancesisnotthatallthingsareonebutthatthereisaOne

itself，-ifwegrantalltheassumptions。Andnoteventhisfollows，if

wedonotgrantthattheuniversalisagenus；andthisinsome

casesitcannotbe。

Norcanitbeexplainedeitherhowthelinesandplanesandsolids

thatcomeafterthenumbersexistorcanexist，orwhatsignificance

theyhave；forthesecanneitherbeForms(fortheyarenot

numbers)，northeintermediates(forthosearetheobjectsof

mathematics)，northeperishablethings。Thisisevidentlya

distinctfourthclass。

Ingeneral，ifwesearchfortheelementsofexistingthings

withoutdistinguishingthemanysensesinwhichthingsaresaidto

exist，wecannotfindthem，especiallyifthesearchforthe

elementsofwhichthingsaremadeisconductedinthismanner。For

itissurelyimpossibletodiscoverwhat’acting’or’beingactedon’，

or’thestraight’，ismadeof，butifelementscanbediscoveredat

all，itisonlytheelementsofsubstances；thereforeeithertoseek

theelementsofallexistingthingsortothinkonehasthemis

incorrect。

Andhowcouldwelearntheelementsofallthings？Evidentlywe

cannotstartbyknowinganythingbefore。Forashewhoislearning

geometry，thoughhemayknowotherthingsbefore，knowsnoneofthe

thingswithwhichthesciencedealsandaboutwhichheistolearn，so

isitinallothercases。Thereforeifthereisascienceofall

things，suchassomeasserttoexist，hewhoislearningthiswill

knownothingbefore。Yetalllearningisbymeansofpremisseswhich

are(eitherallorsomeofthem)knownbefore，-whetherthelearningbe

bydemonstrationorbydefinitions；fortheelementsofthedefinition

mustbeknownbeforeandbefamiliar；andlearningbyinduction

proceedssimilarly。Butagain，ifthesciencewereactuallyinnate，it

werestrangethatweareunawareofourpossessionofthegreatest

ofsciences。

Again，howisonetocometoknowwhatallthingsaremadeof，and

howisthistobemadeevident？Thisalsoaffordsadifficulty；for

theremightbeaconflictofopinion，asthereisaboutcertain

syllables；somesayzaismadeoutofsanddanda，whileothers

sayitisadistinctsoundandnoneofthosethatarefamiliar。

Further，howcouldweknowtheobjectsofsensewithouthavingthe

senseinquestion？Yetweoughtto，iftheelementsofwhichall

thingsconsist，ascomplexsoundsconsistoftheclementsproperto

sound，arethesame。

Itisevident，then，evenfromwhatwehavesaidbefore，that

allmenseemtoseekthecausesnamedinthePhysics，andthatwe

cannotnameanybeyondthese；buttheyseekthesevaguely；and

thoughinasensetheyhaveallbeendescribedbefore，inasensethey

havenotbeendescribedatall。Fortheearliestphilosophyis，onall

subjects，likeonewholisps，sinceitisyoungandinitsbeginnings。

ForevenEmpedoclessaysboneexistsbyvirtueoftheratioinit。Now

thisistheessenceandthesubstanceofthething。Butitis

similarlynecessarythatfleshandeachoftheothertissuesshouldbe

theratioofitselements，orthatnotoneofthemshould；foritis

onaccountofthisthatbothfleshandboneandeverythingelsewill

exist，andnotonaccountofthematter，whichhenames，-fireand

earthandwaterandair。Butwhilehewouldnecessarilyhaveagreedif

anotherhadsaidthis，hehasnotsaiditclearly。

Onthesequestionsourviewshavebeenexpressedbefore；butlet

usreturntoenumeratethedifficultiesthatmightberaisedon

thesesamepoints；forperhapswemaygetfromthemsomehelp

towardsourlaterdifficulties。

THEinvestigationofthetruthisinonewayhard，inanother

easy。Anindicationofthisisfoundinthefactthatnooneisable

toattainthetruthadequately，while，ontheotherhand，wedonot

collectivelyfail，buteveryonesayssomethingtrueaboutthe

natureofthings，andwhileindividuallywecontributelittleor

nothingtothetruth，bytheunionofallaconsiderableamountis

amassed。Therefore，sincethetruthseemstobeliketheproverbial

door，whichnoonecanfailtohit，inthisrespectitmustbeeasy，

butthefactthatwecanhaveawholetruthandnottheparticular

partweaimatshowsthedifficultyofit。

Perhaps，too，asdifficultiesareoftwokinds，thecauseofthe

presentdifficultyisnotinthefactsbutinus。Forastheeyesof

batsaretotheblazeofday，soisthereasoninoursoultothe

thingswhicharebynaturemostevidentofall。

Itisjustthatweshouldbegrateful，notonlytothosewith

whoseviewswemayagree，butalsotothosewhohaveexpressedmore

superficialviews；forthesealsocontributedsomething，bydeveloping

beforeusthepowersofthought。Itistruethatiftherehadbeen

noTimotheusweshouldhavebeenwithoutmuchofourlyricpoetry；but

iftherehadbeennoPhrynistherewouldhavebeennoTimotheus。The

sameholdsgoodofthosewhohaveexpressedviewsaboutthetruth；for

fromsomethinkerswehaveinheritedcertainopinions，whilethe

othershavebeenresponsiblefortheappearanceoftheformer。

Itisrightalsothatphilosophyshouldbecalledknowledgeofthe

truth。Fortheendoftheoreticalknowledgeistruth，whilethatof

practicalknowledgeisaction(foreveniftheyconsiderhowthings

are，practicalmendonotstudytheeternal，butwhatisrelative

andinthepresent)。Nowwedonotknowatruthwithoutitscause；and

athinghasaqualityinahigherdegreethanotherthingsifin

virtueofitthesimilarqualitybelongstotheotherthingsaswell

(e。g。fireisthehottestofthings；foritisthecauseoftheheat

ofallotherthings)；sothatthatcausesderivativetruthstobetrue

ismosttrue。Hencetheprinciplesofeternalthingsmustbealways

mosttrue(fortheyarenotmerelysometimestrue，noristhereany

causeoftheirbeing，buttheythemselvesarethecauseofthebeing

ofotherthings)，sothataseachthingisinrespectofbeing，so

isitinrespectoftruth。