第7章

(1)Firstthenwithregardtowhatwementionedfirst，doesit belongtooneortomoresciencestoinvestigateallthekindsof causes？Howcoulditbelongtoonesciencetorecognizetheprinciples ifthesearenotcontrary？ Further，therearemanythingstowhichnotalltheprinciples pertain。Forhowcanaprincipleofchangeorthenatureofthegood existforunchangeablethings，sinceeverythingthatinitselfand byitsownnatureisgoodisanend，andacauseinthesensethatfor itssaketheotherthingsbothcometobeandare，andsinceanendor purposeistheendofsomeaction，andallactionsimplychange？Soin thecaseofunchangeablethingsthisprinciplecouldnotexist，nor couldtherebeagooditself。Thisiswhyinmathematicsnothingis provedbymeansofthiskindofcause，noristhereany demonstrationofthiskind-’becauseitisbetter，orworse’；indeedno oneevenmentionsanythingofthekind。Andsoforthisreasonsomeof theSophists，e。g。Aristippus，usedtoridiculemathematics；forin thearts(hemaintained)，evenintheindustrialarts，e。g。in carpentryandcobbling，thereasonalwaysgivenis’becauseitis better，orworse，’butthemathematicalsciencestakenoaccountof goodsandevils。 Butifthereareseveralsciencesofthecauses，andadifferent scienceforeachdifferentprinciple，whichofthesesciencesshould besaidtobethatwhichweseek，orwhichofthepeoplewhopossess themhasthemostscientificknowledgeoftheobjectinquestion？ Thesamethingmayhaveallthekindsofcauses，e。g。themovingcause ofahouseistheartorthebuilder，thefinalcauseisthe functionitfulfils，thematterisearthandstones，andtheformis thedefinition。Tojudgefromourpreviousdiscussionofthe questionwhichofthesciencesshouldbecalledWisdom，thereis reasonforapplyingthenametoeachofthem。Forinasmuchasitis mostarchitectonicandauthoritativeandtheothersciences，like slavewomen，maynotevencontradictit，thescienceoftheendand ofthegoodisofthenatureofWisdom(fortheotherthingsarefor thesakeoftheend)。Butinasmuchasitwasdescribed’asdealing withthefirstcausesandthatwhichisinthehighestsenseobjectof knowledge，thescienceofsubstancemustbeofthenatureofWisdom。 Forsincemenmayknowthesamethinginmanyways，wesaythathewho recognizeswhatathingisbyitsbeingsoandsoknowsmorefully thanhewhorecognizesitbyitsnotbeingsoandso，andinthe formerclassitselfoneknowsmorefullythananother，andheknows mostfullywhoknowswhatathingis，nothewhoknowsitsquantityor qualityorwhatitcanbynaturedoorhavedonetoit。Andfurtherin allcasesalsowethinkthattheknowledgeofeachevenofthe thingsofwhichdemonstrationispossibleispresentonlywhenweknow whatthethingis，e。g。whatsquaringarectangleis，viz。thatit isthefindingofamean；andsimilarlyinallothercases。Andwe knowaboutbecomingsandactionsandabouteverychangewhenweknow thesourceofthemovement；andthisisotherthanandopposedto theend。Thereforeitwouldseemtobelongtodifferentsciencesto investigatethesecausesseverally。 But(2)，takingthestarting-pointsofdemonstrationaswellas thecauses，itisadisputablequestionwhethertheyaretheobjectof onescienceorofmore(bythestarting-pointsofdemonstrationImean thecommonbeliefs，onwhichallmenbasetheirproofs)；e。g。that everythingmustbeeitheraffirmedordenied，andthatathing cannotatthesametimebeandnotbe，andallothersuch premisses:-thequestioniswhetherthesamesciencedealswiththemas withsubstance，oradifferentscience，andifitisnotone science，whichofthetwomustbeidentifiedwiththatwhichwenow seek-Itisnotreasonablethatthesetopicsshouldbetheobjectof onescience；forwhyshoulditbepeculiarlyappropriatetogeometry ortoanyothersciencetounderstandthesematters？Ifthenit belongstoeverysciencealike，andcannotbelongtoall，itisnot peculiartothesciencewhichinvestigatessubstances，anymorethan toanyotherscience，toknowaboutthesetopics-And，atthesame time，inwhatwaycantherebeascienceofthefirstprinciples？ Forweareawareevennowwhateachoftheminfactis(atleast evenothersciencesusethemasfamiliar)；butifthereisa demonstrativesciencewhichdealswiththem，therewillhavetobe anunderlyingkind，andsomeofthemmustbedemonstrableattributes andothersmustbeaxioms(foritisimpossiblethatthereshouldbe demonstrationaboutallofthem)；forthedemonstrationmuststart fromcertainpremissesandbeaboutacertainsubjectandprove certainattributes。Thereforeitfollowsthatallattributesthat areprovedmustbelongtoasingleclass；foralldemonstrative sciencesusetheaxioms。 Butifthescienceofsubstanceandthesciencewhichdealswith theaxiomsaredifferent，whichofthemisbynaturemore authoritativeandprior？Theaxiomsaremostuniversalandare principlesofallthings。Andifitisnotthebusinessofthe philosopher，towhomelsewillitbelongtoinquirewhatistrueand whatisuntrueaboutthem？ (3)Ingeneral，doallsubstancesfallunderonescienceor undermorethanone？Ifthelatter，towhatsortofsubstanceisthe presentsciencetobeassigned？-Ontheotherhand，itisnot reasonablethatonescienceshoulddealwithall。Forthentherewould beonedemonstrativesciencedealingwithallattributes。Forever demonstrativescienceinvestigateswithregardtosomesubjectits essentialattributes，startingfromthecommonbeliefs。Thereforeto investigatetheessentialattributesofoneclassofthings， startingfromonesetofbeliefs，isthebusinessofonescience。 Forthesubjectbelongstoonescience，andthepremissesbelongto one，whethertothesameortoanother；sothattheattributesdoso too，whethertheyareinvestigatedbythesesciencesorbyone compoundedoutofthem。 (5)Further，doesourinvestigationdealwithsubstancesalone oralsowiththeirattributes？Imeanforinstance，ifthesolidis asubstanceandsoarelinesandplanes，isitthebusinessofthe samesciencetoknowtheseandtoknowtheattributesofeachofthese classes(theattributesaboutwhichthemathematicalsciencesoffer proofs)，orofadifferentscience？Ifofthesame，thescienceof substancealsomustbeademonstrativescience，butitisthoughtthat thereisnodemonstrationoftheessenceofthings。Andifofanother， whatwillbethesciencethatinvestigatestheattributesof substance？Thisisaverydifficultquestion。 (4)Further，mustwesaythatsensiblesubstancesaloneexist， orthatthereareothersbesidesthese？Andaresubstancesofonekind orarethereinfactseveralkindsofsubstances，asthosesaywho asserttheexistencebothoftheFormsandoftheintermediates， withwhichtheysaythemathematicalsciencesdeal？-Thesenseinwhich wesaytheFormsarebothcausesandself-dependentsubstanceshas beenexplainedinourfirstremarksaboutthem；whilethetheory presentsdifficultiesinmanyways，themostparadoxicalthingof allisthestatementthattherearecertainthingsbesidesthosein thematerialuniverse，andthatthesearethesameassensible thingsexceptthattheyareeternalwhilethelatterareperishable。 Fortheysaythereisaman-himselfandahorse-itselfand health-itself，withnofurtherqualification，-aprocedurelikethatof thepeoplewhosaidtherearegods，butinhumanform。Fortheywere positingnothingbuteternalmen，norarethePlatonistsmakingthe Formsanythingotherthaneternalsensiblethings。 Further，ifwearetopositbesidestheFormsandthesensibles theintermediatesbetweenthem，weshallhavemanydifficulties。For clearlyonthesameprincipletherewillbelinesbesidesthe lines-themselvesandthesensiblelines，andsowitheachoftheother classesofthings；sothatsinceastronomyisoneofthese mathematicalsciencestherewillalsobeaheavenbesidesthesensible heaven，andasunandamoon(andsowiththeotherheavenlybodies) besidesthesensible。Yethowarewetobelieveinthesethings？Itis notreasonableeventosupposesuchabodyimmovable，buttosuppose itmovingisquiteimpossible-Andsimilarlywiththethingsof whichopticsandmathematicalharmonicstreat；forthesealsocannot existapartfromthesensiblethings，forthesamereasons。Forif therearesensiblethingsandsensationsintermediatebetweenFormand individual，evidentlytherewillalsobeanimalsintermediate betweenanimals-themselvesandtheperishableanimals-Wemightalso raisethequestion，withreferencetowhichkindofexistingthingswe mustlookforthesesciencesofintermediates。Ifgeometryisto differfrommensurationonlyinthis，thatthelatterdealswith thingsthatweperceive，andtheformerwiththingsthatarenot perceptible，evidentlytherewillalsobeascienceotherthan medicine，intermediatebetweenmedical-science-itselfandthis individualmedicalscience，andsowitheachoftheothersciences。 Yethowisthispossible？Therewouldhavetobealsohealthythings besidestheperceptiblehealthythingsandthehealthy-itself——Andat thesametimenoteventhisistrue，thatmensurationdealswith perceptibleandperishablemagnitudes；forthenitwouldhaveperished whentheyperished。 Butontheotherhandastronomycannotbedealingwithperceptible magnitudesnorwiththisheavenaboveus。Forneitherare perceptiblelinessuchlinesasthegeometerspeaksof(forno perceptiblethingisstraightorroundinthewayinwhichhe defines’straight’and’round’；forahooptouchesastraightedgenot atapoint，butasProtagorasusedtosayitdid，inhisrefutationof thegeometers)，norarethemovementsandspiralorbitsintheheavens likethoseofwhichastronomytreats，norhavegeometricalpoints thesamenatureastheactualstars-Nowtherearesomewhosaythat theseso-calledintermediatesbetweentheFormsandtheperceptible thingsexist，notapartfromtheperceptiblethings，however，butin these；theimpossibleresultsofthisviewwouldtaketoolongto enumerate，butitisenoughtoconsiderevensuchpointsasthe following:-Itisnotreasonablethatthisshouldbesoonlyinthe caseoftheseintermediates，butclearlytheFormsalsomightbein theperceptiblethings；forbothstatementsarepartsofthesame theory。Further，itfollowsfromthistheorythattherearetwosolids inthesameplace，andthattheintermediatesarenotimmovable，since theyareinthemovingperceptiblethings。Andingeneraltowhat purposewouldonesupposethemtoexistindeed，buttoexistin perceptiblethings？Forthesameparadoxicalresultswillfollowwhich wehavealreadymentioned；therewillbeaheavenbesidesthe heaven，onlyitwillbenotapartbutinthesameplace；whichis stillmoreimpossible。 (6)Apartfromthegreatdifficultyofstatingthecasetrulywith regardtothesematters，itisveryhardtosay，withregardtothe firstprinciples，whetheritisthegenerathatshouldbetakenas elementsandprinciples，orrathertheprimaryconstituentsofa thing；e。g。itistheprimarypartsofwhicharticulatesoundsconsist thatarethoughttobeelementsandprinciplesofarticulatesound， notthecommongenus-articulatesound；andwegivethenameof ’elements’tothosegeometricalpropositions，theproofsofwhich areimpliedintheproofsoftheothers，eitherofallorofmost。 Further，boththosewhosaythereareseveralelementsofcorporeal thingsandthosewhosaythereisone，saythepartsofwhichbodies arecompoundedandconsistareprinciples；e。g。Empedoclessaysfire andwaterandtherestaretheconstituentelementsofthings，but doesnotdescribetheseasgeneraofexistingthings。Besidesthis，if wewanttoexaminethenatureofanythingelse，weexaminetheparts ofwhich，e。g。abedconsistsandhowtheyareputtogether，and thenweknowitsnature。 Tojudgefromthesearguments，then，theprinciplesofthings wouldnotbethegenera；butifweknoweachthingbyits definition，andthegeneraaretheprinciplesorstarting-pointsof definitions，thegeneramustalsobetheprinciplesofdefinable things。Andiftogettheknowledgeofthespeciesaccordingto whichthingsarenamedistogettheknowledgeofthings，thegenera areatleaststarting-pointsofthespecies。Andsomealsoofthose whosayunityorbeing，orthegreatandthesmall，areelementsof things，seemtotreatthemasgenera。 But，again，itisnotpossibletodescribetheprinciplesin bothways。Fortheformulaoftheessenceisone；butdefinitionby generawillbedifferentfromthatwhichstatestheconstituent partsofathing。