Thingsaresaidto’be’1inanaccidentalsense，2bytheir
　　ownnature。
　　1Inanaccidentalsense，e。g。wesay’therighteousdoeris
　　musical’，and’themanismusical’，and’themusicianisaman’，
　　justaswesay’themusicianbuilds’，becausethebuilderhappensto
　　bemusicalorthemusiciantobeabuilder；forhere’onethingis
　　another’means’oneisanaccidentofanother’。Sointhecaseswe
　　havementioned；forwhenwesay’themanismusical’and’themusician
　　isaman’，or’hewhoispaleismusical’or’themusicianispale’，
　　thelasttwomeanthatbothattributesareaccidentsofthesame
　　thing；thefirstthattheattributeisanaccidentofthatwhichis，
　　while’themusicalisaman’meansthat’musical’isanaccidentof
　　aman。Inthissense，too，thenot-paleissaidtobe，becausethat
　　ofwhichitisanaccidentis。Thuswhenonethingissaidinan
　　accidentalsensetobeanother，thisiseitherbecausebothbelong
　　tothesamething，andthisis，orbecausethattowhichtheattribute
　　belongsis，orbecausethesubjectwhichhasasanattributethatof
　　whichitisitselfpredicated，itselfis。
　　2Thekindsofessentialbeingarepreciselythosethatare
　　indicatedbythefiguresofpredication；forthesensesof’being’are
　　justasmanyasthesefigures。Since，then，somepredicatesindicate
　　whatthesubjectis，othersitsquality，othersquantity，others
　　relation，othersactivityorpassivity，othersits’where’，othersits
　　’when’，’being’hasameaningansweringtoeachofthese。Forthereis
　　nodifferencebetween’themanisrecovering’and’theman
　　recovers’，norbetween’themaniswalkingorcutting’and’theman
　　walks’or’cuts’；andsimilarlyinallothercases。
　　Again，’being’and’is’meanthatastatementistrue，’not
　　being’thatitisnottruebutfalses-andthisalikeinthecaseof
　　affirmationandofnegation；e。g。’Socratesismusical’meansthat
　　thisistrue，or’Socratesisnot-pale’meansthatthisistrue；but
　　’thediagonalofthesquareisnotcommensuratewiththeside’means
　　thatitisfalsetosayitis。
　　Again，’being’and’thatwhichis’meanthatsomeofthe
　　thingswehavementioned’are’potentially，othersincomplete
　　reality。Forwesaybothofthatwhichseespotentiallyandofthat
　　whichseesactually，thatitis’seeing’，andbothofthatwhichcan
　　actualizeitsknowledgeandofthatwhichisactualizingit，thatit
　　knows，andbothofthattowhichrestisalreadypresentandofthat
　　whichcanrest，thatitrests。Andsimilarlyinthecaseof
　　substances；wesaytheHermesisinthestone，andthehalfofthe
　　lineisintheline，andwesayofthatwhichisnotyetripethat
　　itiscorn。Whenathingispotentialandwhenitisnotyetpotential
　　mustbeexplainedelsewhere。
　　Wecall’substance’1thesimplebodies，i。e。earthandfireand
　　waterandeverythingofthesort，andingeneralbodiesandthethings
　　composedofthem，bothanimalsanddivinebeings，andthepartsof
　　these。Allthesearecalledsubstancebecausetheyarenot
　　predicatedofasubjectbuteverythingelseispredicatedofthem-2
　　Thatwhich，beingpresentinsuchthingsasarenotpredicatedofa
　　subject，isthecauseoftheirbeing，asthesoulisofthebeingof
　　ananimal-3Thepartswhicharepresentinsuchthings，limiting
　　themandmarkingthemasindividuals，andbywhosedestructionthe
　　wholeisdestroyed，asthebodyisbythedestructionoftheplane，as
　　somesay，andtheplanebythedestructionoftheline；andingeneral
　　numberisthoughtbysometobeofthisnature；forifitis
　　destroyed，theysay，nothingexists，anditlimitsallthings-4The
　　essence，theformulaofwhichisadefinition，isalsocalledthe
　　substanceofeachthing。
　　Itfollows，then，that’substance’hastwosenses，Aultimate
　　substratum，whichisnolongerpredicatedofanythingelse，andB
　　thatwhich，beinga’this’，isalsoseparableandofthisnatureis
　　theshapeorformofeachthing。
　　’Thesame’means1thatwhichisthesameinanaccidental
　　sense，e。g。’thepale’and’themusical’arethesamebecausetheyare
　　accidentsofthesamething，and’aman’and’musical’becausetheone
　　isanaccidentoftheother；and’themusical’is’aman’becauseit
　　isanaccidentoftheman。Thecomplexentityisthesameaseither
　　ofthesimpleonesandeachoftheseisthesameasit；forboth
　　’theman’and’themusical’aresaidtobethesameas’themusical
　　man’，andthisthesameasthey。Thisiswhyallofthese
　　statementsaremadenotuniversally；foritisnottruetosaythat
　　everymanisthesameas’themusical’foruniversalattributes
　　belongtothingsinvirtueoftheirownnature，butaccidentsdonot
　　belongtotheminvirtueoftheirownnature；butofthe
　　individualsthestatementsaremadewithoutqualification。For
　　’Socrates’and’musicalSocrates’arethoughttobethesame；but
　　’Socrates’isnotpredicableofmorethanonesubject，andtherefore
　　wedonotsay’everySocrates’aswesay’everyman’。
　　Somethingsaresaidtobethesameinthissense，others2
　　arethesamebytheirownnature，inasmanysensesasthatwhichis
　　onebyitsownnatureisso；forboththethingswhosematterisone
　　eitherinkindorinnumber，andthosewhoseessenceisone，are
　　saidtobethesame。Clearly，therefore，samenessisaunityofthe
　　beingeitherofmorethanonethingorofonethingwhenitistreated
　　asmorethanone，ie。whenwesayathingisthesameasitself；for
　　wetreatitastwo。
　　Thingsarecalled’other’ifeithertheirkindsortheirmatters
　　orthedefinitionsoftheiressencearemorethanone；andin
　　general’other’hasmeaningsoppositetothoseof’thesame’。
　　’Different’isapplied1tothosethingswhichthoughother
　　arethesameinsomerespect，onlynotinnumberbuteitherinspecies
　　oringenusorbyanalogy；2tothosewhosegenusisother，andto
　　contraries，andtoanthingsthathavetheirothernessintheir
　　essence。
　　Thosethingsarecalled’like’whichhavethesameattributesin
　　everyrespect，andthosewhichhavemoreattributesthesamethan
　　different，andthosewhosequalityisone；andthatwhichshares
　　withanotherthingthegreaternumberorthemoreimportantofthe
　　attributeseachofthemoneoftwocontrariesinrespectofwhich
　　thingsarecapableofaltering，islikethatotherthing。Thesenses
　　of’unlike’areoppositetothoseof’like’。
　　Theterm’opposite’isappliedtocontradictories，andto
　　contraries，andtorelativeterms，andtoprivationandpossession，
　　andtotheextremesfromwhichandintowhichgenerationand
　　dissolutiontakeplace；andtheattributesthatcannotbepresentat
　　thesametimeinthatwhichisreceptiveofboth，aresaidtobe
　　opposed，-eitherthemselvesoftheirconstituents。Greyandwhite
　　colourdonotbelongatthesametimetothesamething；hencetheir
　　constituentsareopposed。
　　Theterm’contrary’isapplied1tothoseattributesdiffering
　　ingenuswhichcannotbelongatthesametimetothesamesubject，2
　　tothemostdifferentofthethingsinthesamegenus，3tothemost
　　differentoftheattributesinthesamerecipientsubject，4to
　　themostdifferentofthethingsthatfallunderthesamefaculty，5
　　tothethingswhosedifferenceisgreatesteitherabsolutelyorin
　　genusorinspecies。Theotherthingsthatarecalledcontraryare
　　socalled，somebecausetheypossesscontrariesoftheabovekind，
　　somebecausetheyarereceptiveofsuch，somebecausetheyare
　　productiveoforsusceptibletosuch，orareproducingorsuffering
　　them，orarelossesoracquisitions，orpossessionsorprivations，
　　ofsuch。Since’one’and’being’havemanysenses，theotherterms
　　whicharederivedfromthese，andtherefore’same’，’other’，and
　　’contrary’，mustcorrespond，sothattheymustbedifferentforeach
　　category。
　　Theterm’otherinspecies’isappliedtothingswhichbeingof
　　thesamegenusarenotsubordinatetheonetotheother，orwhich
　　beinginthesamegenushaveadifference，orwhichhaveacontrariety
　　intheirsubstance；andcontrariesareotherthanoneanotherin
　　specieseitherallcontrariesorthosewhicharesocalledinthe
　　primarysense，andsoarethosethingswhosedefinitionsdifferin
　　theinfimaspeciesofthegenuse。g。manandhorseareindivisiblein
　　genus，buttheirdefinitionsaredifferent，andthosewhichbeing
　　inthesamesubstancehaveadifference。’Thesameinspecies’hasthe
　　variousmeaningsoppositetothese。
　　Thewords’prior’and’posterior’areapplied1tosomethings
　　ontheassumptionthatthereisafirst，i。e。abeginning，ineach
　　classbecausetheyarenearersomebeginningdeterminedeither
　　absolutelyandbynature，orbyreferencetosomethingorinsome
　　placeorbycertainpeople；e。g。thingsarepriorinplacebecause
　　theyarenearereithertosomeplacedeterminedbynaturee。g。the
　　middleorthelastplace，ortosomechanceobject；andthatwhichis
　　fartherisposterior-Otherthingsarepriorintime；somebybeing
　　fartherfromthepresent，i。e。inthecaseofpasteventsforthe
　　TrojanwarispriortothePersian，becauseitisfartherfromthe
　　present，othersbybeingnearerthepresent，i。e。inthecaseof
　　futureeventsfortheNemeangamesarepriortothePythian，ifwe
　　treatthepresentasbeginningandfirstpoint，becausetheyare
　　nearerthepresent-Otherthingsarepriorinmovement；forthat
　　whichisnearerthefirstmoverispriore。g。theboyispriortothe
　　man；andtheprimemoveralsoisabeginningabsolutely-Othersare
　　priorinpower；forthatwhichexceedsinpower，i。e。themore
　　powerful，isprior；andsuchisthataccordingtowhosewillthe
　　other-i。e。theposterior-mustfollow，sothatifthepriordoesnot
　　setitinmotiontheotherdoesnotmove，andifitsetsitin
　　motionitdoesmove；andherewillisabeginning-Othersarepriorin
　　arrangement；thesearethethingsthatareplacedatintervalsin
　　referencetosomeonedefinitethingaccordingtosomerule，e。g。in
　　thechorusthesecondmanispriortothethird，andinthelyrethe
　　secondloweststringispriortothelowest；forintheonecasethe
　　leaderandintheotherthemiddlestringisthebeginning。
　　These，then，arecalledpriorinthissense，but2inanother
　　sensethatwhichispriorforknowledgeistreatedasalso
　　absolutelyprior；ofthese，thethingsthatarepriorindefinitiondo
　　notcoincidewiththosethatarepriorinrelationtoperception。
　　Forindefinitionuniversalsareprior，inrelationtoperception
　　individuals。Andindefinitionalsotheaccidentispriortothe
　　whole，e。g。’musical’to’musicalman’，forthedefinitioncannot
　　existasawholewithoutthepart；yetmusicalnesscannotexistunless
　　thereissomeonewhoismusical。
　　3Theattributesofpriorthingsarecalledprior，e。g。
　　straightnessispriortosmoothness；foroneisanattributeofaline
　　assuch，andtheotherofasurface。
　　Somethingsthenarecalledpriorandposteriorinthissense，
　　others4inrespectofnatureandsubstance，i。e。thosewhichcanbe
　　withoutotherthings，whiletheotherscannotbewithoutthem，-a
　　distinctionwhichPlatoused。Ifweconsiderthevarioussensesof
　　’being’，firstlythesubjectisprior，sothatsubstanceisprior；
　　secondly，accordingaspotencyorcompleterealityistakeninto
　　account，differentthingsareprior，forsomethingsarepriorin
　　respectofpotency，othersinrespectofcompletereality，e。g。in
　　potencythehalflineispriortothewholeline，andthepartto
　　thewhole，andthemattertotheconcretesubstance，butincomplete
　　realitytheseareposterior；foritisonlywhenthewholehasbeen
　　dissolvedthattheywillexistincompletereality。Inasense，
　　therefore，allthingsthatarecalledpriorandposteriorareso
　　calledwithreferencetothisfourthsense；forsomethingscan
　　existwithoutothersinrespectofgeneration，e。g。thewhole
　　withouttheparts，andothersinrespectofdissolution，e。g。thepart
　　withoutthewhole。Andthesameistrueinallothercases。