THEREareseveralsensesinwhichathingmaybesaidto’be’，
　　aswepointedoutpreviouslyinourbookonthevarioussensesof
　　words；’forinonesensethe’being’meantis’whatathingis’ora
　　’this’，andinanothersenseitmeansaqualityorquantityorone
　　oftheotherthingsthatarepredicatedastheseare。While’being’
　　hasallthesesenses，obviouslythatwhich’is’primarilyisthe
　　’what’，whichindicatesthesubstanceofthething。Forwhenwesayof
　　whatqualityathingis，wesaythatitisgoodorbad，notthatitis
　　threecubitslongorthatitisaman；butwhenwesaywhatitis，
　　wedonotsay’white’or’hot’or’threecubitslong’，but’aman’
　　or’a’god’。Andallotherthingsaresaidtobebecausetheyare，
　　someofthem，quantitiesofthatwhichisinthisprimarysense，
　　othersqualitiesofit，othersaffectionsofit，andotherssomeother
　　determinationofit。Andsoonemightevenraisethequestion
　　whetherthewords’towalk’，’tobehealthy’，’tosit’implythateach
　　ofthesethingsisexistent，andsimilarlyinanyothercaseofthis
　　sort；fornoneofthemiseitherself-subsistentorcapableofbeing
　　separatedfromsubstance，butrather，ifanything，itisthatwhich
　　walksorsitsorishealthythatisanexistentthing。Nowtheseare
　　seentobemorerealbecausethereissomethingdefinitewhich
　　underliesthemi。e。thesubstanceorindividual，whichisimpliedin
　　suchapredicate；forweneverusetheword’good’or’sitting’
　　withoutimplyingthis。Clearlythenitisinvirtueofthiscategory
　　thateachoftheothersalsois。Thereforethatwhichisprimarily，
　　i。e。notinaqualifiedsensebutwithoutqualification，mustbe
　　substance。
　　Nowthereareseveralsensesinwhichathingissaidtobefirst；
　　yetsubstanceisfirstineverysense-1indefinition，2in
　　orderofknowledge，3intime。For3oftheothercategories
　　nonecanexistindependently，butonlysubstance。And1in
　　definitionalsothisisfirst；forinthedefinitionofeachterm
　　thedefinitionofitssubstancemustbepresent。And2wethinkwe
　　knoweachthingmostfully，whenweknowwhatitis，e。g。whatman
　　isorwhatfireis，ratherthanwhenweknowitsquality，its
　　quantity，oritsplace；sinceweknoweachofthesepredicatesalso，
　　onlywhenweknowwhatthequantityorthequalityis。
　　Andindeedthequestionwhichwasraisedofoldandisraised
　　nowandalways，andisalwaysthesubjectofdoubt，viz。whatbeing
　　is，isjustthequestion，whatissubstance？Foritisthisthat
　　someasserttobeone，othersmorethanone，andthatsomeassertto
　　belimitedinnumber，othersunlimited。Andsowealsomustconsider
　　chieflyandprimarilyandalmostexclusivelywhatthatiswhichis
　　inthissense。
　　Substanceisthoughttobelongmostobviouslytobodies；andsowe
　　saythatnotonlyanimalsandplantsandtheirpartsaresubstances，
　　butalsonaturalbodiessuchasfireandwaterandearthand
　　everythingofthesort，andallthingsthatareeitherpartsof
　　theseorcomposedoftheseeitherofpartsorofthewholebodies，
　　e。g。thephysicaluniverseanditsparts，starsandmoonandsun。
　　Butwhetherthesealonearesubstances，ortherearealsoothers，or
　　onlysomeofthese，orothersaswell，ornoneofthesebutonly
　　someotherthings，aresubstances，mustbeconsidered。Somethink
　　thelimitsofbody，i。e。surface，line，point，andunit，are
　　substances，andmoresothanbodyorthesolid。
　　Further，somedonotthinkthereisanythingsubstantialbesides
　　sensiblethings，butothersthinkthereareeternalsubstanceswhich
　　aremoreinnumberandmorereal；e。g。Platopositedtwokindsof
　　substance-theFormsandobjectsofmathematics-aswellasathird
　　kind，viz。thesubstanceofsensiblebodies。AndSpeusippusmadestill
　　morekindsofsubstance，beginningwiththeOne，andassuming
　　principlesforeachkindofsubstance，onefornumbers，anotherfor
　　spatialmagnitudes，andthenanotherforthesoul；andbygoingon
　　inthiswayhemultipliesthekindsofsubstance。AndsomesayForms
　　andnumbershavethesamenature，andtheotherthingscomeafter
　　them-linesandplanes-untilwecometothesubstanceofthematerial
　　universeandtosensiblebodies。
　　Regardingthesematters，then，wemustinquirewhichofthecommon
　　statementsarerightandwhicharenotright，andwhatsubstances
　　thereare，andwhetherthereareorarenotanybesidessensible
　　substances，andhowsensiblesubstancesexist，andwhetherthereis
　　asubstancecapableofseparateexistenceandifsowhyandhowor
　　nosuchsubstance，apartfromsensiblesubstances；andwemustfirst
　　sketchthenatureofsubstance。
　　Theword’substance’isapplied，ifnotinmoresenses，stillat
　　leasttofourmainobjects；forboththeessenceandtheuniversaland
　　thegenus，arethoughttobethesubstanceofeachthing，andfourthly
　　thesubstratum。Nowthesubstratumisthatofwhicheverythingelseis
　　predicated，whileitisitselfnotpredicatedofanythingelse。Andso
　　wemustfirstdeterminethenatureofthis；forthatwhichunderliesa
　　thingprimarilyisthoughttobeinthetruestsenseitssubstance。
　　Andinonesensematterissaidtobeofthenatureofsubstratum，
　　inanother，shape，andinathird，thecompoundofthese。Bythe
　　matterImean，forinstance，thebronze，bytheshapethepatternof
　　itsform，andbythecompoundofthesethestatue，theconcrete
　　whole。Thereforeiftheformispriortothematterandmorereal，it
　　willbeprioralsotothecompoundofboth，forthesamereason。
　　Wehavenowoutlinedthenatureofsubstance，showingthatitis
　　thatwhichisnotpredicatedofastratum，butofwhichallelseis
　　predicated。Butwemustnotmerelystatethematterthus；forthis
　　isnotenough。Thestatementitselfisobscure，andfurther，onthis
　　view，matterbecomessubstance。Forifthisisnotsubstance，it
　　bafflesustosaywhatelseis。Whenallelseisstrippedoff
　　evidentlynothingbutmatterremains。Forwhiletherestare
　　affections，products，andpotenciesofbodies，length，breadth，and
　　deptharequantitiesandnotsubstancesforaquantityisnota
　　substance，butthesubstanceisratherthattowhichthesebelong
　　primarily。Butwhenlengthandbreadthanddeptharetakenawaywesee
　　nothingleftunlessthereissomethingthatisboundedbythese；so
　　thattothosewhoconsiderthequestionthusmatteralonemustseemto
　　besubstance。BymatterImeanthatwhichinitselfisneithera
　　particularthingnorofacertainquantitynorassignedtoanyother
　　ofthecategoriesbywhichbeingisdetermined。Forthereissomething
　　ofwhicheachoftheseispredicated，whosebeingisdifferentfrom
　　thatofeachofthepredicatesforthepredicatesotherthan
　　substancearepredicatedofsubstance，whilesubstanceispredicated
　　ofmatter。Thereforetheultimatesubstratumisofitselfneithera
　　particularthingnorofaparticularquantitynorotherwisepositively
　　characterized；noryetisitthenegationsofthese，fornegations
　　alsowillbelongtoitonlybyaccident。
　　Ifweadoptthispointofview，then，itfollowsthatmatteris
　　substance。Butthisisimpossible；forbothseparabilityand
　　’thisness’arethoughttobelongchieflytosubstance。Andsoformand
　　thecompoundofformandmatterwouldbethoughttobesubstance，
　　ratherthanmatter。Thesubstancecompoundedofboth，i。e。ofmatter
　　andshape，maybedismissed；foritisposterioranditsnatureis
　　obvious。Andmatteralsoisinasensemanifest。Butwemustinquire
　　intothethirdkindofsubstance；forthisisthemostperplexing。
　　Someofthesensiblesubstancesaregenerallyadmittedtobe
　　substances，sothatwemustlookfirstamongthese。Foritisan
　　advantagetoadvancetothatwhichismoreknowable。Forlearning
　　proceedsforallinthisway-throughthatwhichislessknowableby
　　naturetothatwhichismoreknowable；andjustasinconductourtask
　　istostartfromwhatisgoodforeachandmakewhatiswithout
　　qualificationgoodgoodforeach，soitisourtasktostartfromwhat
　　ismoreknowabletooneselfandmakewhatisknowablebynature
　　knowabletooneself。Nowwhatisknowableandprimaryforparticular
　　setsofpeopleisoftenknowabletoaverysmallextent，andhas
　　littleornothingofreality。Butyetonemuststartfromthatwhich
　　isbarelyknowablebutknowabletooneself，andtrytoknowwhatis
　　knowablewithoutqualification，passing，ashasbeensaid，bywayof
　　thoseverythingswhichonedoesknow。
　　Sinceatthestartwedistinguishedthevariousmarksbywhich
　　wedeterminesubstance，andoneofthesewasthoughttobethe
　　essence，wemustinvestigatethis。Andfirstletusmakesome
　　linguisticremarksaboutit。Theessenceofeachthingiswhatitis
　　saidtobepropterse。Forbeingyouisnotbeingmusical，sinceyou
　　arenotbyyourverynaturemusical。What，then，youarebyyour
　　verynatureisyouressence。
　　Noryetisthewholeofthistheessenceofathing；notthat
　　whichispropterseaswhiteistoasurface，becausebeinga
　　surfaceisnotidenticalwithbeingwhite。Butagainthecombination
　　ofboth-’beingawhitesurface’-isnottheessenceofsurface，because
　　’surface’itselfisadded。Theformula，therefore，inwhichtheterm
　　itselfisnotpresentbutitsmeaningisexpressed，thisisthe
　　formulaoftheessenceofeachthing。Thereforeiftobeawhite
　　surfaceistobeasmoothsurface，tobewhiteandtobesmoothare
　　oneandthesame。
　　Butsincetherearealsocompoundsansweringtotheother
　　categoriesforthereisasubstratumforeachcategory，e。g。for
　　quality，quantity，time，place，andmotion，wemustinquirewhether
　　thereisaformulaoftheessenceofeachofthem，i。e。whetherto
　　thesecompoundsalsotherebelongsanessence，e。g。’whiteman’。Let
　　thecompoundbedenotedby’cloak’。Whatistheessenceofcloak？But，
　　itmaybesaid，thisalsoisnotapropterseexpression。Wereply
　　thattherearejusttwowaysinwhichapredicatemayfailtobe
　　trueofasubjectpropterse，andoneoftheseresultsfromthe
　　addition，andtheotherfromtheomission，ofadeterminant。One
　　kindofpredicateisnotproptersebecausethetermthatisbeing
　　definediscombinedwithanotherdeterminant，e。g。ifindefining
　　theessenceofwhiteoneweretostatetheformulaofwhiteman；the
　　otherbecauseinthesubjectanotherdeterminantiscombinedwiththat
　　whichisexpressedintheformula，e。g。if’cloak’meant’white
　　man’，andoneweretodefinecloakaswhite；whitemaniswhite
　　indeed，butitsessenceisnottobewhite。
　　Butisbeing-a-cloakanessenceatall？Probablynot。Forthe
　　essenceispreciselywhatsomethingis；butwhenanattributeis
　　assertedofasubjectotherthanitself，thecomplexisnot
　　preciselywhatsome’this’is，e。g。whitemanisnotpreciselywhat
　　some’this’is，sincethisnessbelongsonlytosubstances。Therefore
　　thereisanessenceonlyofthosethingswhoseformulaisa
　　definition。Butwehaveadefinitionnotwherewehaveawordanda
　　formulaidenticalinmeaningforinthatcaseallformulaeorsetsof
　　wordswouldbedefinitions；fortherewillbesomenameforanysetof
　　wordswhatever，sothateventheIliadwillbeadefinition，but
　　wherethereisaformulaofsomethingprimary；andprimarythings
　　arethosewhichdonotimplythepredicationofoneelementinthemof
　　anotherelement。Nothing，then，whichisnotaspeciesofagenuswill
　　haveanessence-onlyspecieswillhaveit，forthesearethoughtto
　　implynotmerelythatthesubjectparticipatesintheattributeand
　　hasitasanaffection，orhasitbyaccident；butforeverthingelse
　　aswell，ifithasaname，therebeaformulaofitsmeaning-viz。that
　　thisattributebelongstothissubject；orinsteadofasimpleformula
　　weshallbeabletogiveamoreaccurateone；buttherewillbeno
　　definitionnoressence。