Orhas’definition’，like’whatathingis’，severalmeanings？
　　’Whatathingis’inonesensemeanssubstanceandthe’this’，in
　　anotheroneorotherofthepredicates，quantity，quality，andthe
　　like。Foras’is’belongstoallthings，nothoweverinthesame
　　sense，buttoonesortofthingprimarilyandtoothersinasecondary
　　way，sotoo’whatathingis’belongsinthesimplesenseto
　　substance，butinalimitedsensetotheothercategories。Forevenof
　　aqualitywemightaskwhatitis，sothatqualityalsoisa’whata
　　thingis’，-notinthesimplesense，however，butjustas，inthe
　　caseofthatwhichisnot，somesay，emphasizingthelinguistic
　　form，thatthatiswhichisnotis-notissimply，butisnon-existent；
　　sotoowithquality。
　　Wemustnodoubtinquirehowweshouldexpressourselvesoneach
　　point，butcertainlynotmorethanhowthefactsactuallystand。And
　　sonowalso，sinceitisevidentwhatlanguageweuse，essencewill
　　belong，justas’whatathingis’does，primarilyandinthesimple
　　sensetosubstance，andinasecondarywaytotheothercategories
　　also，-notessenceinthesimplesense，buttheessenceofaqualityor
　　ofaquantity。Foritmustbeeitherbyanequivocationthatwesay
　　theseare，orbyaddingtoandtakingfromthemeaningof’are’in
　　thewayinwhichthatwhichisnotknownmaybesaidtobeknown，-the
　　truthbeingthatweusethewordneitherambiguouslynorinthesame
　　sense，butjustasweapplytheword’medical’byvirtueofa
　　referencetooneandthesamething，notmeaningoneandthesame
　　thing，noryetspeakingambiguously；forapatientandanoperation
　　andaninstrumentarecalledmedicalneitherbyanambiguitynor
　　withasinglemeaning，butwithreferencetoacommonend。Butitdoes
　　notmatteratallinwhichofthetwowaysonelikestodescribethe
　　facts；thisisevident，thatdefinitionandessenceintheprimaryand
　　simplesensebelongtosubstances。Stilltheybelongtootherthings
　　aswell，onlynotintheprimarysense。Forifwesupposethisitdoes
　　notfollowthatthereisadefinitionofeverywordwhichmeansthe
　　sameasanyformula；itmustmeanthesameasaparticularkindof
　　formula；andthisconditionissatisfiedifitisaformulaof
　　somethingwhichisone，notbycontinuityliketheIliadorthethings
　　thatareonebybeingboundtogether，butinoneofthemainsensesof
　　’one’，whichanswertothesensesof’is’；now’thatwhichis’in
　　onesensedenotesa’this’，inanotheraquantity，inanothera
　　quality。Andsotherecanbeaformulaordefinitionevenofwhite
　　man，butnotinthesenseinwhichthereisadefinitioneitherof
　　whiteorofasubstance。
　　Itisadifficultquestion，ifonedeniesthataformulawithan
　　addeddeterminantisadefinition，whetheranyofthetermsthatare
　　notsimplebutcoupledwillbedefinable。Forwemustexplainthem
　　byaddingadeterminant。E。g。thereisthenose，andconcavity，and
　　snubness，whichiscompoundedoutofthetwobythepresenceofthe
　　oneintheother，anditisnotbyaccidentthatthenosehasthe
　　attributeeitherofconcavityorofsnubness，butinvirtueofits
　　nature；nordotheyattachtoitaswhitenessdoestoCallias，orto
　　manbecauseCallias，whohappenstobeaman，iswhite，butas
　　’male’attachestoanimaland’equal’toquantity，andasall
　　so-called’attributespropterse’attachtotheirsubjects。Andsuch
　　attributesarethoseinwhichisinvolvedeithertheformulaorthe
　　nameofthesubjectoftheparticularattribute，andwhichcannotbe
　　explainedwithoutthis；e。g。whitecanbeexplainedapartfromman，
　　butnotfemaleapartfromanimal。Thereforethereiseithernoessence
　　anddefinitionofanyofthesethings，orifthereis，itisin
　　anothersense，aswehavesaid。
　　Butthereisalsoaseconddifficultyaboutthem。Forifsnubnose
　　andconcavenosearethesamething，snubandconcavewillbethe
　　thing；butifsnubandconcavearenotthesamebecauseitis
　　impossibletospeakofsnubnessapartfromthethingofwhichitisan
　　attributepropterse，forsnubnessisconcavity-in-a-nose，either
　　itisimpossibletosay’snubnose’orthesamethingwillhavebeen
　　saidtwice，concave-nosenose；forsnubnosewillbeconcave-nose
　　nose。Andsoitisabsurdthatsuchthingsshouldhaveanessence；
　　iftheyhave，therewillbeaninfiniteregress；forinsnub-nosenose
　　yetanother’nose’willbeinvolved。
　　Clearly，then，onlysubstanceisdefinable。Foriftheother
　　categoriesalsoaredefinable，itmustbebyadditionofa
　　determinant，e。g。thequalitativeisdefinedthus，andsoisthe
　　odd，foritcannotbedefinedapartfromnumber；norcanfemalebe
　　definedapartfromanimal。WhenIsay’byaddition’Imeanthe
　　expressionsinwhichitturnsoutthatwearesayingthesamething
　　twice，asintheseinstances。Andifthisistrue，coupledterms
　　also，like’oddnumber’，willnotbedefinablebutthisescapesour
　　noticebecauseourformulaearenotaccurate。。Butifthesealso
　　aredefinable，eitheritisinsomeotherwayor，aswedefinitionand
　　essencemustbesaidtohavemorethanonesense。Thereforeinone
　　sensenothingwillhaveadefinitionandnothingwillhaveanessence，
　　exceptsubstances，butinanothersenseotherthingswillhavethem。
　　Clearly，then，definitionistheformulaoftheessence，andessence
　　belongstosubstanceseitheraloneorchieflyandprimarilyandinthe
　　unqualifiedsense。
　　Wemustinquirewhethereachthinganditsessencearethesameor
　　different。Thisisofsomeusefortheinquiryconcerningsubstance；
　　foreachthingisthoughttobenotdifferentfromitssubstance，
　　andtheessenceissaidtobethesubstanceofeachthing。
　　Nowinthecaseofaccidentalunitiesthetwowouldbegenerally
　　thoughttobedifferent，e。g。whitemanwouldbethoughttobe
　　differentfromtheessenceofwhiteman。Foriftheyarethesame，the
　　essenceofmanandthatofwhitemanarealsothesame；foraman
　　andawhitemanarethesamething，aspeoplesay，sothattheessence
　　ofwhitemanandthatofmanwouldbealsothesame。Butperhapsit
　　doesnotfollowthattheessenceofaccidentalunitiesshouldbethe
　　sameasthatofthesimpleterms。Fortheextremetermsarenotinthe
　　samewayidenticalwiththemiddleterm。Butperhapsthismightbe
　　thoughttofollow，thattheextremeterms，theaccidents，should
　　turnouttobethesame，e。g。theessenceofwhiteandthatof
　　musical；butthisisnotactuallythoughttobethecase。
　　Butinthecaseofso-calledself-subsistentthings，isathing
　　necessarilythesameasitsessence？E。g。iftherearesomesubstances
　　whichhavenoothersubstancesnorentitiespriortothem-substances
　　suchassomeasserttheIdeastobe？-Iftheessenceofgoodistobe
　　differentfromgood-itself，andtheessenceofanimalfrom
　　animal-itself，andtheessenceofbeingfrombeing-itself，therewill，
　　firstly，beothersubstancesandentitiesandIdeasbesidesthose
　　whichareasserted，and，secondly，theseotherswillbeprior
　　substances，ifessenceissubstance。Andiftheposteriorsubstances
　　andthepriorareseveredfromeachother，atherewillbeno
　　knowledgeoftheformer，andbthelatterwillhavenobeing。By
　　’severed’Imean，ifthegood-itselfhasnottheessenceofgood，
　　andthelatterhasnotthepropertyofbeinggood。Forathereis
　　knowledgeofeachthingonlywhenweknowitsessence。Andbthe
　　caseisthesameforotherthingsasforthegood；sothatifthe
　　essenceofgoodisnotgood，neitheristheessenceofrealityreal，
　　northeessenceofunityone。Andallessencesalikeexistornone
　　ofthemdoes；sothatiftheessenceofrealityisnotreal，neither
　　isanyoftheothers。Again，thattowhichtheessenceofgooddoes
　　notbelongisnotgood-Thegood，then，mustbeonewiththeessence
　　ofgood，andthebeautifulwiththeessenceofbeauty，andsowithall
　　thingswhichdonotdependonsomethingelsebutareself-subsistent
　　andprimary。Foritisenoughiftheyarethis，eveniftheyarenot
　　Forms；orrather，perhaps，eveniftheyareForms。Atthesametime
　　itisclearthatifthereareIdeassuchassomepeoplesaythereare，
　　itwillnotbesubstratumthatissubstance；forthesemustbe
　　substances，butnotpredicableofasubstratum；foriftheywere
　　theywouldexistonlybybeingparticipatedin。
　　Eachthingitself，then，anditsessenceareoneandthesamein
　　nomerelyaccidentalway，asisevidentbothfromthepreceding
　　argumentsandbecausetoknoweachthing，atleast，isjusttoknow
　　itsessence，sothatevenbytheexhibitionofinstancesitbecomes
　　clearthatbothmustbeone。
　　Butofanaccidentalterm，e。g。’themusical’or’thewhite’，
　　sinceithastwomeanings，itisnottruetosaythatititselfis
　　identicalwithitsessence；forboththattowhichtheaccidental
　　qualitybelongs，andtheaccidentalquality，arewhite，sothatina
　　sensetheaccidentanditsessencearethesame，andinasensethey
　　arenot；fortheessenceofwhiteisnotthesameasthemanorthe
　　whiteman，butitisthesameastheattributewhite。
　　Theabsurdityoftheseparationwouldappearalsoifonewereto
　　assignanametoeachoftheessences；fortherewouldbeyet
　　anotheressencebesidestheoriginalone，e。g。totheessenceofhorse
　　therewillbelongasecondessence。Yetwhyshouldnotsomethings
　　betheiressencesfromthestart，sinceessenceissubstance？But
　　indeednotonlyareathinganditsessenceone，buttheformulaof
　　themisalsothesame，asisclearevenfromwhathasbeensaid；for
　　itisnotbyaccidentthattheessenceofone，andtheone，areone。
　　Further，iftheyaretobedifferent，theprocesswillgoonto
　　infinity；forweshallhave1theessenceofone，and2theone，
　　sothattotermsoftheformerkindthesameargumentwillbe
　　applicable。
　　Clearly，then，eachprimaryandself-subsistentthingisoneand
　　thesameasitsessence。Thesophisticalobjectionstothis
　　position，andthequestionwhetherSocratesandtobeSocratesarethe
　　samething，areobviouslyansweredbythesamesolution；forthere
　　isnodifferenceeitherinthestandpointfromwhichthequestion
　　wouldbeasked，orinthatfromwhichonecouldanswerit
　　successfully。Wehaveexplained，then，inwhatsenseeachthingisthe
　　sameasitsessenceandinwhatsenseitisnot。
　　Ofthingsthatcometobe，somecometobebynature，somebyart，
　　somespontaneously。Noweverythingthatcomestobecomestobebythe
　　agencyofsomethingandfromsomethingandcomestobesomething。
　　AndthesomethingwhichIsayitcomestobemaybefoundinany
　　category；itmaycometobeeithera’this’orofsomesizeorofsome
　　qualityorsomewhere。
　　Nownaturalcomingstobearethecomingstobeofthosethings
　　whichcometobebynature；andthatoutofwhichtheycometobeis
　　whatwecallmatter；andthatbywhichtheycometobeissomething
　　whichexistsnaturally；andthesomethingwhichtheycometobeisa
　　manoraplantoroneofthethingsofthiskind，whichwesayare
　　substancesifanythingis-allthingsproducedeitherbynatureorby
　　arthavematter；foreachofthemiscapablebothofbeingandof
　　notbeing，andthiscapacityisthematterineach-and，ingeneral，
　　boththatfromwhichtheyareproducedisnature，andthetype
　　accordingtowhichtheyareproducedisnatureforthatwhichis
　　produced，e。g。aplantorananimal，hasanature，andsoisthat
　　bywhichtheyareproduced——theso-called’formal’nature，whichis
　　specificallythesamethoughthisisinanotherindividual；for
　　manbegetsman。