WEareseekingtheprinciplesandthecausesofthethingsthat
　　are，andobviouslyofthemquabeing。For，whilethereisacauseof
　　healthandofgoodcondition，andtheobjectsofmathematicshave
　　firstprinciplesandelementsandcauses，andingeneraleveryscience
　　whichisratiocinativeoratallinvolvesreasoningdealswith
　　causesandprinciples，moreorlessprecise，allthesesciencesmark
　　offsomeparticularbeing-somegenus，andinquireintothis，butnot
　　intobeingsimplynorquabeing，nordotheyofferanydiscussionof
　　theessenceofthethingsofwhichtheytreat；butstartingfromthe
　　essence-somemakingitplaintothesenses，othersassumingitasa
　　hypothesis-theythendemonstrate，moreorlesscogently，theessential
　　attributesofthegenuswithwhichtheydeal。Itisobvious，
　　therefore，thatsuchaninductionyieldsnodemonstrationofsubstance
　　oroftheessence，butsomeotherwayofexhibitingit。And
　　similarlythesciencesomitthequestionwhetherthegenuswith
　　whichtheydealexistsordoesnotexist，becauseitbelongstothe
　　samekindofthinkingtoshowwhatitisandthatitis。
　　Andsincenaturalscience，likeothersciences，isinfactabout
　　oneclassofbeing，i。e。tothatsortofsubstancewhichhasthe
　　principleofitsmovementandrestpresentinitself，evidentlyit
　　isneitherpracticalnorproductive。Forinthecaseofthingsmade
　　theprincipleisinthemaker-itiseitherreasonorartorsome
　　faculty，whileinthecaseofthingsdoneitisinthedoer-viz。will，
　　forthatwhichisdoneandthatwhichiswilledarethesame。
　　Therefore，ifallthoughtiseitherpracticalorproductiveor
　　theoretical，physicsmustbeatheoreticalscience，butitwill
　　theorizeaboutsuchbeingasadmitsofbeingmoved，andabout
　　substance-as-definedforthemostpartonlyasnotseparablefrom
　　matter。Now，wemustnotfailtonoticethemodeofbeingofthe
　　essenceandofitsdefinition，for，withoutthis，inquiryisbutidle。
　　Ofthingsdefined，i。e。of’whats’，somearelike’snub’，andsome
　　like’concave’。Andthesedifferbecause’snub’isboundupwith
　　matterforwhatissnubisaconcavenose，whileconcavityis
　　independentofperceptiblematter。Ifthenallnaturalthingsarea
　　analogoustothesnubintheirnature；e。g。nose，eye，face，flesh，
　　bone，and，ingeneral，animal；leaf，root，bark，and，ingeneral，
　　plantfornoneofthesecanbedefinedwithoutreferenceto
　　movement-theyalwayshavematter，itisclearhowwemustseekand
　　definethe’what’inthecaseofnaturalobjects，andalsothatit
　　belongstothestudentofnaturetostudyevensoulinacertain
　　sense，i。e。somuchofitasisnotindependentofmatter。
　　Thatphysics，then，isatheoreticalscience，isplainfrom
　　theseconsiderations。Mathematicsalso，however，istheoretical；but
　　whetheritsobjectsareimmovableandseparablefrommatter，isnotat
　　presentclear；still，itisclearthatsomemathematicaltheorems
　　considerthemquaimmovableandquaseparablefrommatter。Butif
　　thereissomethingwhichiseternalandimmovableandseparable，
　　clearlytheknowledgeofitbelongstoatheoreticalscience，-not，
　　however，tophysicsforphysicsdealswithcertainmovablethings
　　nortomathematics，buttoasciencepriortoboth。Forphysics
　　dealswiththingswhichexistseparatelybutarenotimmovable，and
　　somepartsofmathematicsdealwiththingswhichareimmovablebut
　　presumablydonotexistseparately，butasembodiedinmatter；while
　　thefirstsciencedealswiththingswhichbothexistseparatelyand
　　areimmovable。Nowallcausesmustbeeternal，butespeciallythese；
　　fortheyarethecausesthatoperateonsomuchofthedivineas
　　appearstous。Theremust，then，bethreetheoreticalphilosophies，
　　mathematics，physics，andwhatwemaycalltheology，sinceitis
　　obviousthatifthedivineispresentanywhere，itispresentin
　　thingsofthissort。Andthehighestsciencemustdealwiththe
　　highestgenus。Thus，whilethetheoreticalsciencesaremoretobe
　　desiredthantheothersciences，thisismoretobedesiredthanthe
　　othertheoreticalsciences。Foronemightraisethequestionwhether
　　firstphilosophyisuniversal，ordealswithonegenus，i。e。some
　　onekindofbeing；fornoteventhemathematicalsciencesareall
　　alikeinthisrespect，-geometryandastronomydealwithacertain
　　particularkindofthing，whileuniversalmathematicsappliesaliketo
　　all。Weanswerthatifthereisnosubstanceotherthanthosewhich
　　areformedbynature，naturalsciencewillbethefirstscience；but
　　ifthereisanimmovablesubstance，thescienceofthismustbe
　　priorandmustbefirstphilosophy，anduniversalinthisway，because
　　itisfirst。Anditwillbelongtothistoconsiderbeingqua
　　being-bothwhatitisandtheattributeswhichbelongtoitquabeing。
　　Butsincetheunqualifiedterm’being’hasseveralmeanings，of
　　whichonewasseen’tobetheaccidental，andanotherthetrue
　　’non-being’beingthefalse，whilebesidesthesetherearethe
　　figuresofpredicatione。g。the’what’，quality，quantity，place，
　　time，andanysimilarmeaningswhich’being’mayhave，andagain
　　besidesallthesethereisthatwhich’is’potentiallyor
　　actually:-since’being’hasmanymeanings，wemustsayregardingthe
　　accidental，thattherecanbenoscientifictreatmentofit。Thisis
　　confirmedbythefactthatnosciencepractical，productive，or
　　theoreticaltroublesitselfaboutit。Forontheonehandhewho
　　producesahousedoesnotproducealltheattributesthatcomeinto
　　beingalongwiththehouse；fortheseareinnumerable；thehouse
　　thathasbeenmademayquitewellbepleasantforsomepeople，hurtful
　　forsome，andusefultoothers，anddifferent-toputitshortlyfrom
　　allthingsthatare；andthescienceofbuildingdoesnotaimat
　　producinganyoftheseattributes。Andinthesamewaythegeometer
　　doesnotconsidertheattributeswhichattachthustofigures，nor
　　whether’triangle’isdifferentfrom’trianglewhoseanglesare
　　equaltotworightangles’-Andthishappensnaturallyenough；forthe
　　accidentalispracticallyamerename。AndsoPlatowasinasensenot
　　wronginrankingsophisticasdealingwiththatwhichisnot。For
　　theargumentsofthesophistsdeal，wemaysay，aboveallwiththe
　　accidental；e。g。thequestionwhether’musical’and’lettered’are
　　differentorthesame，andwhether’musicalCoriscus’and’Coriscus’
　　arethesame，andwhether’everythingwhichis，butisnoteternal，
　　hascometobe’，withtheparadoxicalconclusionthatifonewhowas
　　musicalhascometobelettered，hemustalsohavebeenletteredand
　　havecometobemusical，andalltheotherargumentsofthissort；the
　　accidentalisobviouslyakintonon-being。Andthisisclearalsofrom
　　argumentssuchasthefollowing:thingswhichareinanothersense
　　comeintobeingandpassoutofbeingbyaprocess，butthingswhich
　　areaccidentallydonot。Butstillwemust，asfaraswecan，say
　　further，regardingtheaccidental，whatitsnatureisandfromwhat
　　causeitproceeds；foritwillperhapsatthesametimebecomeclear
　　whythereisnoscienceofit。
　　Since，amongthingswhichare，somearealwaysinthesamestate
　　andareofnecessitynotnecessityinthesenseofcompulsionbut
　　thatwhichweassertofthingsbecausetheycannotbeotherwise，
　　andsomearenotofnecessitynoralways，butforthemostpart，
　　thisistheprincipleandthisthecauseoftheexistenceofthe
　　accidental；forthatwhichisneitheralwaysnorforthemostpart，we
　　callaccidental。Forinstance，ifinthedog-daysthereiswintry
　　andcoldweather，wesaythisisanaccident，butnotifthereis
　　sultryheat，becausethelatterisalwaysorforthemostpartso，but
　　nottheformer。Anditisanaccidentthatamanispaleforthis
　　isneitheralwaysnorforthemostpartso，butitisnotbyaccident
　　thatheisananimal。Andthatthebuilderproduceshealthisan
　　accident，becauseitisthenaturenotofthebuilderbutofthe
　　doctortodothis，-butthebuilderhappenedtobeadoctor。Again，a
　　confectioner，aimingatgivingpleasure，maymakesomethingwholesome，
　　butnotinvirtueoftheconfectioner’sart；andthereforewesay
　　’itwasanaccident’，andwhilethereisasenseinwhichhemakesit，
　　intheunqualifiedsensehedoesnot。Fortootherthingsanswer
　　facultiesproductiveofthem，buttoaccidentalresultsthere
　　correspondsnodeterminateartnorfaculty；forofthingswhichareor
　　cometobebyaccident，thecausealsoisaccidental。Therefore，since
　　notallthingseitherareorcometobeofnecessityandalways，
　　but，themajorityofthingsareforthemostpart，theaccidentalmust
　　exist；forinstanceapalemanisnotalwaysnorforthemostpart
　　musical，butsincethissometimeshappens，itmustbeaccidentalif
　　not，everythingwillbeofnecessity。Thematter，therefore，whichis
　　capableofbeingotherwisethanasitusuallyis，mustbethecauseof
　　theaccidental。Andwemusttakeasourstarting-pointthequestion
　　whetherthereisnothingthatisneitheralwaysnorforthemostpart。
　　Surelythisisimpossible。Thereis，then，besidesthesesomething
　　whichisfortuitousandaccidental。Butwhiletheusualexists，can
　　nothingbesaidtobealways，orarethereeternalthings？Thismust
　　beconsideredlater，’butthatthereisnoscienceoftheaccidental
　　isobvious；forallscienceiseitherofthatwhichisalwaysorof
　　thatwhichisforthemostpart。Forhowelseisonetolearnorto
　　teachanother？Thethingmustbedeterminedasoccurringeitheralways
　　orforthemostpart，e。g。thathoney-waterisusefulforapatientin
　　afeveristrueforthemostpart。Butthatwhichiscontraryto
　　theusuallawsciencewillbeunabletostate，i。e。whenthething
　　doesnothappen，e。g。’onthedayofnewmoon’；foreventhatwhich
　　happensonthedayofnewmoonhappenstheneitheralwaysorforthe
　　mostpart；buttheaccidentaliscontrarytosuchlaws。Wehave
　　stated，then，whattheaccidentalis，andfromwhatcauseitarises，
　　andthatthereisnosciencewhichdealswithit
　　Thatthereareprinciplesandcauseswhicharegenerableand
　　destructiblewithouteverbeingincourseofbeinggeneratedor
　　destroyed，isobvious。Forotherwiseallthingswillbeof
　　necessity，sincethatwhichisbeinggeneratedordestroyedmust
　　haveacausewhichisnotaccidentallyitscause。WillAexistornot？
　　ItwillifBhappens；andifnot，not。AndBwillexistifC
　　happens。Andthusiftimeisconstantlysubtractedfromalimited
　　extentoftime，onewillobviouslycometothepresent。Thisman，
　　then，willdiebyviolence，ifhegoesout；andhewilldothisif
　　hegetsthirsty；andhewillgetthirstyifsomethingelsehappens；
　　andthusweshallcometothatwhichisnowpresent，ortosomepast
　　event。Forinstance，hewillgooutifhegetsthirsty；andhewill
　　getthirstyifheiseatingpungentfood；andthisiseitherthe
　　caseornot；sothathewillofnecessitydie，orofnecessitynot
　　die。Andsimilarlyifonejumpsovertopastevents，thesame
　　accountwillholdgood；forthis-Imeanthepastcondition-is
　　alreadypresentinsomething。Everything，therefore，thatwillbe，
　　willbeofnecessity；e。g。itisnecessarythathewholivesshallone
　　daydie；foralreadysomeconditionhascomeintoexistence，e。g。
　　thepresenceofcontrariesinthesamebody。Butwhetherheisto
　　diebydiseaseorbyviolenceisnotyetdetermined，butdependson
　　thehappeningofsomethingelse。Clearlythentheprocessgoesbackto
　　acertainstarting-point，butthisnolongerpointstosomething
　　further。Thisthenwillbethestarting-pointforthefortuitous，
　　andwillhavenothingelseascauseofitscomingtobe。Buttowhat
　　sortofstarting-pointandwhatsortofcausewethusreferthe
　　fortuitous-whethertomatterortothepurposeortothemotivepower，
　　mustbecarefullyconsidered。
　　Letusdismissaccidentalbeing；forwehavesufficiently
　　determineditsnature。Butsincethatwhichisinthesenseofbeing
　　true，orisnotinthesenseofbeingfalse，dependsoncombination
　　andseparation，andtruthandfalsitytogetherdependonthe
　　allocationofapairofcontradictoryjudgementsforthetrue
　　judgementaffirmswherethesubjectandpredicatereallyarecombined，
　　anddenieswheretheyareseparated，whilethefalsejudgementhasthe
　　oppositeofthisallocation；itisanotherquestion，howithappens
　　thatwethinkthingstogetherorapart；by’together’and’apart’I
　　meanthinkingthemsothatthereisnosuccessioninthethoughts
　　buttheybecomeaunity；forfalsityandtrutharenotinthings-it
　　isnotasifthegoodweretrue，andthebadwereinitself
　　false-butinthought；whilewithregardtosimpleconceptsand’whats’
　　falsityandtruthdonotexisteveninthought——thisbeingso，wemust
　　considerlaterwhathastobediscussedwithregardtothatwhichis
　　orisnotinthissense。Butsincethecombinationandthe
　　separationareinthoughtandnotinthethings，andthatwhichis
　　inthissenseisadifferentsortof’being’fromthethingsthat
　　areinthefullsenseforthethoughtattachesorremoveseither
　　thesubject’s’what’oritshavingacertainqualityorquantityor
　　somethingelse，thatwhichisaccidentallyandthatwhichisinthe
　　senseofbeingtruemustbedismissed。Forthecauseoftheformer
　　isindeterminate，andthatofthelatterissomeaffectionofthe
　　thought，andbotharerelatedtotheremaininggenusofbeing，and
　　donotindicatetheexistenceofanyseparateclassofbeing。
　　Thereforeletthesebedismissed，andletusconsiderthecausesand
　　theprinciplesofbeingitself，quabeing。Itwasclearinour
　　discussionofthevariousmeaningsofterms，that’being’has
　　severalmeanings。