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。