Again，itwouldseemimpossiblethatthesubstanceandthatof
　　whichitisthesubstanceshouldexistapart；how，therefore，could
　　theIdeas，beingthesubstancesofthings，existapart？InthePhaedo’
　　thecaseisstatedinthisway-thattheFormsarecausesbothofbeing
　　andofbecoming；yetwhentheFormsexist，stillthethingsthatshare
　　inthemdonotcomeintobeing，unlessthereissomethingtooriginate
　　movement；andmanyotherthingscomeintobeinge。g。ahouseora
　　ringofwhichwesaytherearenoForms。Clearly，therefore，eventhe
　　otherthingscanbothbeandcomeintobeingowingtosuchcausesas
　　producethethingsjustmentioned。
　　Again，iftheFormsarenumbers，howcantheybecauses？Isit
　　becauseexistingthingsareothernumbers，e。g。onenumberisman，
　　anotherisSocrates，anotherCallias？Whythenaretheonesetof
　　numberscausesoftheotherset？Itwillnotmakeanydifference
　　eveniftheformerareeternalandthelatterarenot。Butifitis
　　becausethingsinthissensibleworlde。g。harmonyareratiosof
　　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，andalsoiftheyarenotalikeneitherthe
　　unitsinonenumberbeingthemselveslikeoneanothernorthosein
　　othernumbersbeingallliketoall；forinwhatwilltheydiffer，as
　　theyarewithoutquality？Thisisnotaplausibleview，norisit
　　consistentwithourthoughtonthematter。
　　Further，theymustsetupasecondkindofnumberwithwhich
　　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
　　thatlinescomefromtheshortandlongi。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，wehavegiventhisupforwesaynothingofthecausefrom
　　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；forthesecanneitherbeFormsfortheyarenot
　　numbers，northeintermediatesforthosearetheobjectsof
　　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
　　areeitherallorsomeofthemknownbefore，-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
　　practicalknowledgeisactionforeveniftheyconsiderhowthings
　　are，practicalmendonotstudytheeternal，butwhatisrelative
　　andinthepresent。Nowwedonotknowatruthwithoutitscause；and
　　athinghasaqualityinahigherdegreethanotherthingsifin
　　virtueofitthesimilarqualitybelongstotheotherthingsaswell
　　e。g。fireisthehottestofthings；foritisthecauseoftheheat
　　ofallotherthings；sothatthatcausesderivativetruthstobetrue
　　ismosttrue。Hencetheprinciplesofeternalthingsmustbealways
　　mosttruefortheyarenotmerelysometimestrue，noristhereany
　　causeoftheirbeing，buttheythemselvesarethecauseofthebeing
　　ofotherthings，sothataseachthingisinrespectofbeing，so
　　isitinrespectoftruth。