ChapterIV
Weshouldnowseehowessencesexistinseparatedsubstances，thatis，inthesoul，intheintelligences，andinthefirstcause。Now，whileeveryoneconcedesthesimplicityofthefirstcause，somepeoplehavetriedtointroduceintotheintelligencesandthesoulacompositionofformandmatter，apositionthatseemstohavebegunwithAvicebron，theauthorofthebookcalledFonsVitae。Butthisviewisrepugnanttothecommonteachingofthephilosophers，fortheycallthesethingssubstancesseparatedfrommatter，andtheyprovethemtobewhollywithoutmatter。Themostcogentdemonstrationofthisproceedsfromtheexcellenceofunderstandingfoundinthesesubstances。Forweseethatformsarenotactuallyintelligibleexceptastheyareseparatedfrommatteranditsconditions，andformsarenotmadeactuallyintelligibleexceptbyvirtueofanintelligentsubstance，whicheducestheformsandreceivestheminitself。Hence，inanyintelligentsubstancethereisacompleteabsenceofmatterinsuchawaythatthesubstancehasneitheramaterialpartitselfnorevenisthesubstancelikeaformimpressedinmatter，asisthecasewithmaterialforms。
Norcansomeonesaythatonlycorporealmatter，andnotsomeotherkindofmatter，impedesintelligibility。For，ifitwereonlycorporealmaterthatimpedesintelligibility，thensincematteriscalledcorporealonlyinsofarasitexistsunderacorporealform，matter’simpedingintelligibilitywouldcomefromthecorporealform；andthisisimpossible，forthecorporealformisactuallyintelligiblejustlikeanyotherform，insofarasitisabstractedfrommatter。Hence，innowayisthereacompositionofmatterandformineitherthesoulortheintelligences，suchthatanessenceisreceivedintheseasincorporealsubstances。Nevertheless，inseparatesubstancesthereisacompositionofformandexistence，andsointheLiberdeCausis，prop。9，com。，itissaidthattheintelligenceshaveformandexistence，andinthisplaceformistakeninthesenseofasimplequiddityornature。
Itiseasytoseehowthisisthecase。Whenevertwothingsarerelatedtoeachothersuchthatoneisthecauseoftheother，theonethatisthecausecanhaveexistencewithouttheother，butnotconversely。Now，wefindthatmatterandformarerelatedinsuchawaythatformgivesexistencetomatter，andthereforeitisimpossiblethatmatterexistwithoutaform；butitisnotimpossiblethataformexistwithoutmatter，foraform，insofarasitisaform，isnotdependentonmatter。Whenwefindaformthatcannotexistexceptinmatter，thishappensbecausesuchformsaredistantfromthefirstprinciple，whichisprimaryandpureact。Hence，thoseformsthatarenearestthefirstprinciplearesubsistingformsessentiallywithoutmatter，fornotthewholegenusofformsrequiresmatter，assaidabove，andtheintelligencesareformsofthistype。Thus，theessencesorquidditiesofthesesubstancesarenototherthantheformsthemselves。
Therefore，theessenceofacompositesubstanceandthatofasimplesubstancedifferinthattheessenceofacompositesubstanceisnotformalonebutembracesbothformandmatter，whiletheessenceofasimplesubstanceisformalone。Andfromthistwootherdifferencesarise。Oneisthattheessenceofacompositesubstancecanbesignifiedasawholeorasapart，whichhappensbecauseofthedesignationofthematter，assaidabove。Hence，inoneway，theessenceofacompositethingisnotpredicatedofthecompositethingitself，forwecannotsaythatamanishisownquiddity。Buttheessenceofasimplething，whichisitsform，cannotbesignifiedexceptasawhole，asinthiscasethereisnothingbeyondtheformthatmightreceivethequiddity，andso，howeverwetaketheessenceofasimplething，theessenceispredicatedofit。Hence，AvicennasaysinMetaphysicaeV，cap。5that\"thequiddityofasimplethingisthesimplethingitself，\"becausethereisnootherthingtoreceivetheform。Theseconddifferenceisthattheessencesofcompositethings，becausetheyarereceivedindesignatematter，aremultipliedaccordingtothedivisionofmatter，andsoithappensthatsomethingsarethesameinspeciesbutdifferentinnumber。Butsincetheessenceofasimplethingisnotreceivedinmatter，therecanbenosuchmultiplicationinthiscase，andsoamongsuchsubstanceswedonotfindmanyindividualsofthesamespecies，asAvicennaexpresslysaysinMetaphysicaeV，cap。
2。
Althoughsubstancesofthiskindareformaloneandarewithoutmatter，theyareneverthelessnotineverywaysimple，andtheyarenotpureact；
rather，theyhaveanadmixtureofpotency，andthiscanbeseenasfollows。
Whateverisnotintheconceptoftheessenceorthequidditycomesfrombeyondtheessenceandmakesacompositionwiththeessence，becausenoessencecanbeunderstoodwithoutthethingsthatareitsparts。Buteveryessenceorquidditycanbeunderstoodwithoutunderstandinganythingaboutitsexistence:Icanunderstandwhatamanisorwhataphoenixisandneverthelessnotknowwhethereitherhasexistenceinreality。Therefore，itisclearthatexistenceissomethingotherthantheessenceorquiddity，unlessperhapsthereissomethingwhosequiddityisitsveryownexistence，andthisthingmustbeoneandprimary。For，therecanbenoplurificationofsomethingexceptbytheadditionofsomedifference，asthenatureofagenusismultipliedinitsspecies；oras，sincetheformisreceivedindiversematters，thenatureofthespeciesismultipliedindiverseindividuals；oragainaswhenonethingisabsoluteandanotherisreceivedinsomethingelse，asiftherewereacertainseparateheatthatwasotherthanunseparatedheatbyreasonofitsownseparation。Butifwepositathingthatisexistenceonly，suchthatitissubsistingexistenceitself，thisexistencewillnotreceivetheadditionofadifference，for，iftherewereaddedadifference，therewouldbenotonlyexistencebutexistenceandalsobeyondthissomeform；muchlesswouldsuchathingreceivetheadditionofmatter，forthenthethingwouldbenotsubsistingexistencebutmaterialexistence。Hence，itremainsthatathingthatisitsownexistencecannotbeotherthanone，andsoineveryotherthing，thething’sexistenceisonething，anditsessenceorquiddityornatureorformisanother。Intheintelligences，therefore，thereisexistencebeyondtheform，andsowesaythatanintelligenceisformandexistence。
Everythingthatpertainstoathing，however，eitheriscausedbytheprinciplesofitsownnature，asrisibilityinman，orelsecomesfromsomeextrinsicprinciple，aslightintheairfromtheinfluenceofthesun。Now，itcannotbethatexistenceitselfiscausedbytheveryformorquiddityofthething（Imeanasbyanefficientcause），becausethenthethingwouldbeitsownefficientcause，andthethingwouldproduceitselfinexistence，whichisimpossible。Therefore，everythingtheexistenceofwhichisotherthanitsownnaturehasexistencefromanother。Andsinceeverythingthatisthroughanotherisreducedtothatwhichisthroughitselfastoafirstcause，thereissomethingthatisthecauseofexistinginallthingsinthatthisthingisexistenceonly。Otherwise，wewouldhavetogotoinfinityincauses，foreverythingthatisnotexistencealonehasacauseofitsexistence，assaidabove。Itisclear，therefore，thattheintelligencesareformandexistenceandhaveexistencefromthefirstbeing，whichisexistencealone，andthisisthefirstcause，whichisGod。
Everythingthatreceivessomethingfromanotherisinpotencywithrespecttowhatitreceives，andthatwhichisreceivedinthethingisitsact；
therefore，aquiddityorformthatisanintelligenceisinpotencywithrespecttotheexistencethatitreceivesfromGod，andthisreceivedexistenceisreceivedasitsact。Andthustherearefoundintheintelligencesbothpotencyandactbutnotmatterandform，unlessinsomeequivocalsense。
Sotootosuffer，toreceive，tobeasubjectandeverythingofthistypethatseemtopertaintothingsbyreasonoftheirmatteraresaidofintellectualsubstancesandcorporealsubstancesequivocally，astheCommentatorsaysinDeAnimaIII，com。14。Furthermore，since，assaidabove，thequiddityofanintelligenceistheintelligenceitself，itsquiddityoressenceisitselftheverythingthatexists，anditsexistencereceivedfromGodisthatbywhichitsubsistsinthenatureofthings；andbecauseofthissomepeoplesaythatsubstancesofthiskindarecomposedofwhatisandthatbywhichitis，orofwhatisandexistence，asBoethiussaysinDeHebdomadibus（PL64，1311B—C）。
Moreover，sincewepositintheintelligencespotencyandact，itwillnotbedifficulttofindamultitudeofintelligences，whichwouldbeimpossibleiftherewereinthemnopotency。Hence，theCommentatorsaysinDeAnimaIII，com。5thatifthenatureofthepossibleintellectwereunknown，wewouldnotbeabletofindamultitudeofseparatesubstances。
Thereisthusadistinctionamongseparatesubstancesaccordingtotheirgradeofpotencyandactsuchthatthesuperiorintelligences，whicharenearerthefirstcause，havemoreactandlesspotency，andsoon。
Thisscalecomestoanendwiththehumansoul，whichholdsthelowestplaceamongintellectualsubstances。Thesoul’spossibleintellectisrelatedtointelligibleformsjustasprimematter（whichholdsthelowestplaceinsensibleexistence）isrelatedtosensibleforms，astheCommentatorsaysinDeAnimaIII，com。5。ThePhilosopherthuscompares，IIIDeAnimacap。4（430a1），thesoultoatabletonwhichnothinghasbeenwritten。Since，amongintellectualsubstances，thesoulhasthemostpotency，itissoclosetomaterialthingsthatamaterialthingisbroughttoparticipateinitsexistence:thatis，fromthesoulandthebodythereresultsoneexistenceinonecompositething，althoughthisexistence，astheexistenceofthesoul，isnotdependentonthebody。Therefore，beyondthisformthatisthesoul，thereareotherformshavingmorepotencyandbeingclosertomatter，andsomuchsothattheyhavenoexistencewithoutmatter。Amongtheseformsthereisanorderandgradationdowntotheprimaryformsoftheelements，whichareclosesttomatter；andsothesehavenooperationexceptasrequiredbytheactiveandpassivequalitiesandothersuchqualitiesbywhichmatterisdisposedbyform。ChapterV
Havingtreatedthesematters，wecanseeclearlyhowessenceisfoundinvariouskindsofthings。Therearethreewaysinwhichsubstancesmayhaveanessence。First，surely，isthewayGodhashisessence，whichishisveryexistenceitself，andsowefindcertainphilosopherssayingthatGoddoesnothaveaquiddityoressencebecausehisessenceisnototherthanhisexistence。Fromthisitfollowsthatheisnotinagenus，foreverythingthatisinagenushasaquidditybeyonditsexistence，sincethequiddityornatureofthegenusorspeciesisnotintheorderofnaturedistinguishedinthethingsofwhichitisthegenusorspecies，buttheexistenceisdiverseindiversethings。
EventhoughwesaythatGodisexistencealonewedonotfallintotheerrorofthosewhosaidthatGodisthatuniversalexistencebywhicheverythingformallyexists。TheexistencewhichisGodisofsuchakindthatnoadditioncanbemadetoit，whencethroughitspurityitisdistinctfromeveryotherexistence；forthisreasontheauthoroftheLiberdeCausis，prop。9，com。，saysthattheindividuationofthefirstcause，whichisbeingalone，isthroughitspuregoodness。Butcommonexistence，justasitdoesnotincludeinitsconceptanyaddition，sotooinitsconceptdoesitnotexcludeanyaddition；for，ifsuchexistencedidinitsconceptexcludeanyaddition，nothingcouldbeunderstoodtoexistinwhichtherewasaddedsomethingbeyondexistence。
Similarly，althoughGodisexistencealone，theremainingperfectionsandnobilitiesarenotlackinginhim。Onthecontrary，hehasalltheperfectionsthatexistineverygenus，andforthisreasonheiscalledperfectwithoutqualification，asthePhilosopher，VMetaphysicaecap。16（1021b30—33），andtheCommentator，MetaphysicaeV，com。
21，eachsay。ButGodhastheseperfectionsinamoreexcellentwaythanallotherthingshavethembecauseinhimtheyareone，whileinotherthingstheyarediverse。AndthisisbecausealltheseperfectionspertaintoGodaccordingtohissimpleexistence，justas，ifsomeonethroughonequalitycouldeffecttheoperationsofallqualities，suchapersonwouldhaveinthatonequalityallthequalities，sotoodoesGodinhisveryexistencehavealltheperfections。
Inasecondway，essenceisfoundincreatedintellectualsubstances，inwhichexistenceisotherthanessence，althoughinthesesubstancestheessenceiswithoutmatter。Hence，theirexistenceisnotabsolutebutreceived，andsofiniteandlimitedbythecapacityofthereceivingnature；
buttheirnatureorquiddityisabsoluteandisnotreceivedinanymatter。
Thus，theauthoroftheLiberdeCausis，prop。16，com。，saysthatintelligencesareinfiniteinaninferiorwayandfiniteinasuperiorway:theyarefinitewithrespecttotheirexistence，whichtheyreceivefromsomethingsuperior，thoughtheyarenotrenderedfiniteinaninferiorwaybecausetheirformsarenotlimitedtothecapacityofsomematterreceivingthem。Andthusamongsuchsubstanceswedonotfindamultitudeofindividualsinonespecies，assaidabove，exceptinthecaseofthehumansoul，andtherewedofindamultitudeofindividualsinonespeciesbecauseofthebodytowhichthesoulisunited。Now，theindividuationofthesouldependsonthebody，inanoccasionalmanner，astoitsinception，forthesouldoesnotacquireforitselfindividualexistenceunlessinthebodyofwhichitistheact。Butnevertheless，ifwesubtractthebody，theindividuationdoesnotperishbecause，sincethesoulwasmadetheformofagivenbody，theformhasabsoluteexistencefromwhichithasacquiredindividuatedexistence，andthisexistencealwaysremainsindividuated。
AndthusAvicennasays，DeAnimaV，cap。3，thattheindividuationofsoulsandtheirmultiplicationdependonthebodyfortheirbeginningbutnotfortheirend。
Sinceinthesesubstancesthequiddityisnotthesameasexistence，thesesubstancescanbeorderedinapredicament，andforthisreasonwefindamongthesethingsgenera，species，anddifferences，althoughtheirproperdifferencesarehiddenfromus。Insensiblethingseventheessentialdifferencesareunknowntous，andsotheyaresignifiedthroughaccidentaldifferencesthatarisefromtheessentialones，justasacauseissignifiedthroughitseffect。Wetakebipedality，forexample，asthedifferenceofman。Theproperaccidentsofimmaterialsubstances，however，areunknowntous，andthuswecansignifytheirdifferencesneitherpersenorthroughtheiraccidentaldifferences。
Weshouldnote，though，thatthegenusanddifferenceinimmaterialsubstancesarenottakeninthesamewayasinsensiblesubstances，forinsensiblesubstancesthegenusistakenfromthatwhichismaterialinthething，whilethedifferenceistakenfromthatwhichisformalinthething。Hence，Avicennasays，DeAnimaI，cap。1，that，inthingscomposedofformandmatter，theform\"isitssimpledifferencebecausethethingisconstitutedfromit，\"not，however，becausetheformisthedifferencebutratherbecauseitistheprincipleofthedifference，asAvicennahimselfsaysinhisMetaphysicaeV，cap。6。Further，thisdifferenceiscalledasimpledifferencebecauseitistakenfromthatwhichisapartofthequiddityofthething，namely，fromtheform。Butsinceimmaterialsubstancesaresimplequiddities，insuchsubstancesthedifferencecannotbetakenfromthatwhichisapartofthequidditybutonlyfromthewholequiddity，andsoinDeAnimaI，cap。1，Avicennasaysthatsubstances\"havenosimpledifferenceexceptforthosespeciesofwhichtheessencesarecomposedofmatterandform。\"
Similarly，inimmaterialthingsthegenusistakenfromthewholeessence，thoughnotinthesamewayasthedifferenceis。Oneseparatedsubstanceislikeanotherwithrespecttotheirimmateriality，buttheydifferonefromanotherwithrespecttotheirgradeofperfectionaccordingtohowfareachrecedesfrompotentialityandapproachespureact。Andso，insuchsubstances，thegenusistakenfromthatwhicharisesinthesesubstancesinsofarastheyareimmaterial，asintellectualityandsuchthings；thedifference，however，istakenfromthatwhicharisesinthesesubstancesfromtheirgradeofperfection，althoughthesedifferencesareunknowntous。Norarethesedifferencesaccidentalbecausetheyarisefromgreaterandlesserperfection，whichdonotdiversifythespecies。For，whilethegradeofperfectioninreceivingthesameformdoesnotdiversifythespecies（aswhiterandlesswhiteinparticipatinginwhitenessofthesametype），nevertheless，adifferentgradeofperfectionintheseparticipatedformsornaturesdoesdiversifythespecies，justasnatureproceedsbygradesfromplantstoanimalsthroughthosethingsthataremedianbetweenplantsandanimals，asthePhilosophersaysinVIIIDeHistoriaAnimaliumcap。1（588b4—12）。Norisitnecessarythatthedivisionofintellectualsubstancesalwaysbemadethroughtwotruedifferences，foritisimpossiblethatthishappeninallthings，asthePhilosophersaysinIDePartibusAnimaliumcap。2（642b5—7）。
Inathirdway，essenceisfoundinsubstancescomposedofmatterandform，inwhichexistenceisbothreceivedandlimitedbecausesuchsubstanceshaveexistencefromanother，andagainbecausethenatureorquiddityofsuchsubstancesisreceivedinsignatematter。Andthussuchsubstancesarefiniteinbothasuperiorwayandaninferiorway，andamongsuchsubstances，becauseofthedivisionofsignatematter，therecanbeamultiplicationofindividualsinonespecies。Thewaysinwhichtheessenceinsuchsubstancesisrelatedtothelogicalintentionswehaveexplainedabove。ChapterVI
Weshouldnowseeinwhatwaythereareessencesinaccidents，havingsaidalreadyhowessencesarefoundinalltypesofsubstances。Now，since，assaidabove，theessenceisthatwhichissignifiedbythedefinition，accidentswillthushaveessencesinthesamewayinwhichtheyhavedefinitions。
Butaccidentshaveincompletedefinitions，becausetheycannotbedefinedunlessweputasubjectintheirdefinitions，andthisisbecausetheydonothaveabsoluteexistenceperseapartfromasubject，butjustasfromtheformandthemattersubstantialexistenceresultswhenasubstanceiscompounded，sotoofromtheaccidentandthesubjectdoesaccidentalexistenceresultwhentheaccidentcomestothesubject。Thus，neitherthesubstantialformnorthematterhasacompleteessence，foreveninthedefinitionofthesubstantialformweplacesomethingofwhichitistheform，andsoitsdefinitioninvolvestheadditionofsomethingthatisbeyonditsgenus，justaswiththedefinitionofanaccidentalform。
Hence，thenaturalphilosopherplacesthebodyinthedefinitionofthesoulbecauseheconsidersthesoulonlyinsofarasitistheformofthephysicalbody。
Butthisisthecaseonlywithsubstantialandaccidentalformsbecause，justasthesubstantialformhasnoabsoluteexistencepersewithoutthattowhichtheformcomes，sotoodoesthattowhichtheformcomes，namelymatter，havenoabsoluteperseexistence。Thus，fromtheconjunctionofboththereresultsthatexistenceinwhichthethingpersesubsists，andfromthesetwothereismadeonethingperse；for，fromtheconjunctionofthesethereresultsacertainessence。Hence，althoughconsideredinitselftheformdoesnothavethecompleteaspectofanessence，neverthelessitispartofacompleteessence。Butthattowhichanaccidentcomesisinitselfacompletebeingsubsistinginitsownexistence，andthisexistencenaturallyprecedestheaccidentthatsupervenes。Therefore，thesuperveningaccident，fromitsconjunctionwiththethingtowhichitcomes，doesnotcausethatexistenceinwhichthethingsubsists，theexistencethroughwhichthethingisabeingperse；itcauses，rather，acertainsecondaryexistencewithoutwhichthesubsistingbeingcanbeunderstoodtoexist，aswhatisfirstcanbeunderstoodwithoutwhatissecond。Hence，fromtheaccidentandthesubjectthereismadesomethingthatisoneaccidentally，notessentially；andsofromtheconjunctionofthesetwotheredoesnotresultanessence，astheredoesfromtheconjunctionofformandmatter。
Andsoanaccidenthasneithertheaspectofacompleteessencenorisitapartofanessence；rather，justasanaccidentisabeingonlyinacertainsense，sotoodoesithaveanessenceonlyinacertainsense。
Butsincethatwhichisgreatestandtruestinagenusisthecauseofthelesserthingsinthegenus（asfire，whichisattheextremeofheat，isthecauseofheatinotherhotthings，asthePhilosophersaysinIIMetaphysicaecap。1（993b24—27）），thussubstance，whichisfirstinthegenusofbeingsandwhichhasessenceinthetruestandgreatestway，isthecauseofaccidents，whichparticipateinthenotionofbeingonlysecondarilyandinacertainsense。Butthishappensinavarietyofways。Sincethepartsofsubstancearematterandform，certainaccidentsareprincipallyaconsequenceofform，andcertainaccidentsareprincipallyaconsequenceofmatter。Now，whilewefindsomeforms，liketheintellectualsoul，whoseexistencedoesnotdependonmatter，matterdoesnothaveexistenceexceptthroughform。Hence，amongthoseaccidentsthatareaconsequenceofform，therearesomethathavenocommunicationwithmatter，suchasunderstanding，whichdoesnottakeplacethroughacorporealorgan，asthePhilosopherprovesinIIIDeAnimacap。1（429a18—b5）。Otheraccidentsthatareaconsequenceofformdohavecommunicationwithmatter，andamongtheseissensation。Butnoaccidentaconsequenceofmatteriswithoutsomecommunicationwithform。
Amongtheaccidentsthatareconsequencesofmatterthereisfoundacertaindiversity。Someaccidentsfollowfromtheorderthematterhastoaspecialform，asthemasculineandthefeminineinanimals，thedifferencebetweenwhichisreducedtothematter，asthePhilosophersaysinXMetaphysicaecap。9（1058b21—23）。Hence，theformoftheanimalhavingbeenremoved，theseaccidentsdonotremainexceptinsomeequivocalsense。Otheraccidentsfollowfromtheorderthematterhastoageneralform，andsowiththeseaccidents，ifthespecialformisremoved，theaccidentsstillremaininthething，astheblacknessoftheskinofanEthiopiancomesfromthemixtureoftheelementsandnotfromthenotionofthesoul，andhencetheblacknessremainsinthemanafterdeath。
Sinceeverythingisindividuatedbymatterandisplacedinitsgenusorspeciesthroughitsform，theaccidentsthatfollowfromthematterareaccidentsoftheindividual，andbytheseaccidentsindividualsofthesamespeciesdifferonefromanother。Buttheaccidentsthatfollowfromtheformareproperlypassionsofthegenusorspecies，andsotheyarefoundinallthingsparticipatinginthenatureofthegenusorspecies，asrisibilityinmanfollowsfromtheform，forlaughtercomesfromacertainkindofunderstandinginthesoulofman。
Weshouldalsonotethatsomeaccidentsarecausedbytheessentialprinciplesofathingaccordingtoitsperfectact，asheatinfire，whichisalwayshot，whileotheraccidentsaretheresultofanaptitudeinthesubstance，andinsuchcasesthecompleteaccidentarisesfromanexterioragent，astransparencyinair，whichiscompletedthroughanexteriorluminescentbody。Insuchthings，theaptitudeisaninseparableaccident，butthecomplement，whichcomesfromsomeprinciplethatisbeyondtheessenceofthething，orthatdoesnotenterintotheconstitutionofthething，isseparable，astheabilitytobemoved，andsoon。
Weshouldfurthernotethatinaccidents，thegenus，difference，andspeciesaretakeninawaydifferentfromthatinsubstances。Forinsubstances，fromthesubstantialformandthematterthereismadesomethingoneperse，acertainsinglenatureresultingfromtheconjunctionofthesetwo，andthisnatureisproperlyplacedinthepredicamentofsubstance。Hence，insubstances，theconcretetermsthatsignifythecompositeareproperlysaidtobeinthegenus，inthemannerofthespeciesorthegenus，as，forexample，manoranimal。Butinthiswayneithertheformnorthematterisinapredicamentexceptbymeansofreduction，aswhenwesaythattheprinciplesofathingareinitsgenus。However，fromtheaccidentandthesubjecttheredoesnotresultsomethingthatisoneperse，andthusfromtheconjunctionofthesetwotheredoesnotresultanaturetowhichtheintentionofgenusorspeciesmightbeattributed。Therefore，theaccidentaltermstakenconcretely，likewhiteormusical，cannotbeplacedinapredicamentexceptbymeansofreduction；buttheycanbeplacedinapredicamentwhentheyaresignifiedabstractly，aswhitenessandmusic。Andbecauseaccidentsarenotcomposedofmatterandform，inaccidentsthegenuscannotbetakenfromthematter，thedifferencefromtheform，asisthecasewithcompositesubstances；rather，thefirstgenusistakenfromtheirverymodeofexisting，asbeingissaidindifferentwaysaccordingtowhatispriorandwhatisposteriorinthetengeneraofpredicaments，andthuswecallthemeasureofasubstancequantity，thedispositionofasubstancequality，andsoonfortheothers，asthePhilosophersaysinIXMetaphysicaecap。
1（1045b27—32）。
Thedifferencesinaccidentsaretakenfromthediversityofprinciplesbywhichtheyarecaused。Sincepassionsareproperlycausedbytheproperprinciplesofthesubject，thesubjectisplacedinthedefinitionofthepassioninplaceofthedifferenceifthepassionisbeingdefinedintheabstractandproperlyinitsgenus，aswhenwesaythathavingasnubnoseistheupwardcurvatureofthenose。Butitwouldbetheconverseifthedefinitionofthepassionweretakenaccordingtoitsconcretesense；inthisway，thesubjectisplacedinthedefinitionasagenus，forthenthepassionisdefinedinthemodeofcompositesubstancesinwhichthenotionofthegenusistakenfromthematter，aswhenwesaythatasnubnoseisanupwardlycurvingnose。Thecaseissimilarwhenoneaccidentistheprincipleofanother，astheprincipleofrelationisactionandpassionandquantity，andthusbyreferencetothesethePhilosopherdividesrelationinVMetaphysicaecap。15（1020b26—32）。Butbecausetheproperprinciplesofaccidentsarenotalwaysmanifest，wesometimestakethedifferencesofaccidentsfromtheireffects，aswedowiththeconcentrativeandthediffusive，whicharecalledthedifferencesofcolorandwhicharecausedbytheabundanceorthepaucityoflight，whichcausethedifferentspeciesofcolor。
Wehavethusmadeclearhowessenceisfoundinsubstancesandinaccidents，andhowincompositesubstancesandinsimpleones，andinwhatwaytheuniversalintentionsoflogicarefoundinallofthese，exceptforthefirstbeing，whichistheextremeofsimplicityandtowhich，becauseofitssimplicity，thenotionsofgenus，species，andthusdefinitiondonotapply；andhavingsaidthiswemaymakeanproperendtothisdiscourse。
Amen。
NOTES:
[1]ThistranslationfollowstheLeonineEditionofAquinas’works，vol。43SanctiThomaeDeAquinoOperaOmnia368—381（Rome1976）。
[2]Allpersonsarelicensedtoreproducethistranslationandthefootnotesheretoforpersonaloreducationalpurposes，providedthatthenoticeofcopyrightsetforthaboveandthisnoticeareincludedintheirrespectiveentiretiesinallcopies。Thislicenseincludesreproductionbyacommercialentityengagedinthebusinessofprovidingcopyingservicesifsuchreproductionismadepursuanttoanagreementtheotherpartytowhichwouldbelicensedundertheprecedingsentencetoreproducethistranslationforpersonaloreducationalpurposes。
[3]Althoughquotedbyvariousthirteenthcenturyauthors，thisstatementdoesnotappearinthetextofDePersonaetDuabusNaturisaswehaveit。
[4]AquinasknewthisbookasBookXI。