posterior analytics- 第14部分

such　is　the　proper　object　of　opinion；　while　the　necessary　is　the



object　of　knowledge。



　　In　what　sense；　then；　can　the　same　thing　be　the　object　of　both



opinion　and　knowledge？　And　if　any　one　chooses　to　maintain　that　all



that　he　knows　he　can　also　opine；　why　should　not　opinion　be



knowledge？　For　he　that　knows　and　he　that　opines　will　follow　the　same



train　of　thought　through　the　same　middle　terms　until　the　immediate



premisses　are　reached；　because　it　is　possible　to　opine　not　only　the



fact　but　also　the　reasoned　fact；　and　the　reason　is　the　middle　term；　so



that；　since　the　former　knows；　he　that　opines　also　has　knowledge。



　　The　truth　perhaps　is　that　if　a　man　grasp　truths　that　cannot　be　other



than　they　are；　in　the　way　in　which　he　grasps　the　definitions　through



which　demonstrations　take　place；　he　will　have　not　opinion　but



knowledge：　if　on　the　other　hand　he　apprehends　these　attributes　as



inhering　in　their　subjects；　but　not　in　virtue　of　the　subjects'



substance　and　essential　nature　possesses　opinion　and　not　genuine



knowledge；　and　his　opinion；　if　obtained　through　immediate　premisses；



will　be　both　of　the　fact　and　of　the　reasoned　fact；　if　not　so　obtained；



of　the　fact　alone。　The　object　of　opinion　and　knowledge　is　not　quite



identical；　it　is　only　in　a　sense　identical；　just　as　the　object　of　true



and　false　opinion　is　in　a　sense　identical。　The　sense　in　which　some



maintain　that　true　and　false　opinion　can　have　the　same　object　leads



them　to　embrace　many　strange　doctrines；　particularly　the　doctrine　that



what　a　man　opines　falsely　he　does　not　opine　at　all。　There　are　really



many　senses　of　'identical'；　and　in　one　sense　the　object　of　true　and



false　opinion　can　be　the　same；　in　another　it　cannot。　Thus；　to　have　a



true　opinion　that　the　diagonal　is　commensurate　with　the　side　would



be　absurd：　but　because　the　diagonal　with　which　they　are　both　concerned



is　the　same；　the　two　opinions　have　objects　so　far　the　same：　on　the



other　hand；　as　regards　their　essential　definable　nature　these



objects　differ。　The　identity　of　the　objects　of　knowledge　and　opinion



is　similar。　Knowledge　is　the　apprehension　of；　e。g。　the　attribute



'animal'　as　incapable　of　being　otherwise；　opinion　the　apprehension



of　'animal'　as　capable　of　being　otherwise…e。g。　the　apprehension　that



animal　is　an　element　in　the　essential　nature　of　man　is　knowledge；



the　apprehension　of　animal　as　predicable　of　man　but　not　as　an



element　in　man's　essential　nature　is　opinion：　man　is　the　subject　in



both　judgements；　but　the　mode　of　inherence　differs。



　　This　also　shows　that　one　cannot　opine　and　know　the　same　thing



simultaneously；　for　then　one　would　apprehend　the　same　thing　as　both



capable　and　incapable　of　being　otherwise…an　impossibility。　Knowledge



and　opinion　of　the　same　thing　can　co…exist　in　two　different　people



in　the　sense　we　have　explained；　but　not　simultaneously　in　the　same



person。　That　would　involve　a　man's　simultaneously　apprehending；　e。g。



（1）　that　man　is　essentially　animal…i。e。　cannot　be　other　than



animal…and　（2）　that　man　is　not　essentially　animal；　that　is；　we　may



assume；　may　be　other　than　animal。



　　Further　consideration　of　modes　of　thinking　and　their　distribution



under　the　heads　of　discursive　thought；　intuition；　science；　art；



practical　wisdom；　and　metaphysical　thinking；　belongs　rather　partly



to　natural　science；　partly　to　moral　philosophy。







　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　34







　　Quick　wit　is　a　faculty　of　hitting　upon　the　middle　term



instantaneously。　It　would　be　exemplified　by　a　man　who　saw　that　the



moon　has　her　bright　side　always　turned　towards　the　sun；　and　quickly



grasped　the　cause　of　this；　namely　that　she　borrows　her　light　from　him；



or　observed　somebody　in　conversation　with　a　man　of　wealth　and



divined　that　he　was　borrowing　money；　or　that　the　friendship　of　these



people　sprang　from　a　common　enmity。　In　all　these　instances　he　has　seen



the　major　and　minor　terms　and　then　grasped　the　causes；　the　middle



terms。



　　Let　A　represent　'bright　side　turned　sunward'；　B　'lighted　from　the



sun'；　C　the　moon。　Then　B；　'lighted　from　the　sun'　is　predicable　of　C；



the　moon；　and　A；　'having　her　bright　side　towards　the　source　of　her



light'；　is　predicable　of　B。　So　A　is　predicable　of　C　through　B。











　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　Book　II



　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　1







　　THE　kinds　of　question　we　ask　are　as　many　as　the　kinds　of　things



which　we　know。　They　are　in　fact　four：…（1）　whether　the　connexion　of



an　attribute　with　a　thing　is　a　fact；　（2）　what　is　the　reason　of　the



connexion；　（3）　whether　a　thing　exists；　（4）　What　is　the　nature　of　the



thing。　Thus；　when　our　question　concerns　a　complex　of　thing　and



attribute　and　we　ask　whether　the　thing　is　thus　or　otherwise



qualified…whether；　e。g。　the　sun　suffers　eclipse　or　not…then　we　are



asking　as　to　the　fact　of　a　connexion。　That　our　inquiry　ceases　with　the



discovery　that　the　sun　does　suffer　eclipse　is　an　indication　of　this；



and　if　we　know　from　the　start　that　the　sun　suffers　eclipse；　we　do



not　inquire　whether　it　does　so　or　not。　On　the　other　hand；　when　we　know



the　fact　we　ask　the　reason；　as；　for　example；　when　we　know　that　the　sun



is　being　eclipsed　and　that　an　earthquake　is　in　progress；　it　is　the



reason　of　eclipse　or　earthquake　into　which　we　inquire。



　　Where　a　complex　is　concerned；　then；　those　are　the　two　questions　we



ask；　but　for　some　objects　of　inquiry　we　have　a　different　kind　of



question　to　ask；　such　as　whether　there　is　or　is　not　a　centaur　or　a



God。　（By　'is　or　is　not'　I　mean　'is　or　is　not；　without　further



qualification'；　as　opposed　to　'is　or　is　not　＇e。g。＇　white'。）　On　the



other　hand；　when　we　have　ascertained　the　thing's　existence；　we　inquire



as　to　its　nature；　asking；　for　instance；　'what；　then；　is　God？'　or　'what



is　man？'。







　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　2







　　These；　then；　are　the　four　kinds　of　question　we　ask；　and　it　is　in　the



answers　to　these　questions　that　our　knowledge　consists。



　　Now　when　we　ask　whether　a　connexion　is　a　fact；　or　whether　a　thing



without　qualification　is；　we　are　really　asking　whether　the　connexion



or　the　thing　has　a　'middle'；　and　when　we　have　ascertained　either



that　the　connexion　is　a　fact　or　that　the　thing　is…i。e。　ascertained



either　the　partial　or　the　unqualified　being　of　the　thing…and　are



proceeding　to　ask　the　reason　of　the　connexion　or　the　nature　of　the



thing；　then　we　are　asking　what　the　'middle'　is。



　　（By　distinguishing　the　fact　of　the　connexion　and　the　existence　of



the　thing　as　respectively　the　partial　and　the　unqualified　being　of　the



thing；　I　mean　that　if　we　ask　'does　the　moon　suffer　eclipse？'；　or　'does



the　moon　wax？'；　the　question　concerns　a　part　of　the　thing's　being；　for



what　we　are　asking　in　such　questions　is　whether　a　thing　is　this　or



that；　i。e。　has　or　has　not　this　or　that　attribute：　whereas；　if　we　ask



whether　the　moon　or　night　exists；　the　question　concerns　the



unqualified　being　of　a　thing。）



　　We　conclude　that　in　all　our　inquiries　we　are　asking　either　whether



there　is　a　'middle'　or　what　the　'middle'　is：　for　the　'middle'　here



is　precisely　the　cause；　and　it　is　the　cause　that　we　seek　in　all　our



inquiries。　Thus；　'Does　the　moon　suffer　eclipse？'　means　'Is　there　or　is



there　not　a　cause　producing　eclipse　of　the　moon？'；　and　when　we　have



learnt　that　there　is；　our　next　question　is；　'What；　then；　is　this



cause？　for　the　cause　through　which　a　thing　is…not　is　this　or　that；



i。e。　has　this　or　that　attribute；　but　without　qualification　is…and



the　cause　through　which　it　is…not　is　without　qualification；　but　is



this　or　that　as　having　some　essential　attribute　or　some　accident…are



both　alike　the　middle'。　By　that　which　is　without　qualification　I



mean　the　subject；　e。g。　moon　or　earth　or　sun　or　triangle；　by　that　which



a　subject　is　（in　the　partial　sense）　I　mean　a　property；　e。g。　eclipse；



equality　or　inequality；　interposition　or　non…interposition。　For　in　all



these　examples　it　is　clear　that　the　nature　of　the　thing　and　the　reason



of　the　fact　are　identical：　the　question　'What　is　eclipse？'　and　its



answer　'The　privation　of　the　moon's　light　by　the　interposition　of



the　earth'　are　identical　with　the　question　'What　is　the　reason　of



eclipse？'　or　'Why　does　the　moon　suffer　eclipse？'　and　the　reply



'Because　of　the　failure　of　light　through　the　earth's　shutting　it　out'。



Again；　for　'What　is　a　concord？　A　commensurate　numerical　ratio　of　a



high　and　a　low　note'；　we　may　substitute　'What　ratio　makes　a　high　and　a



low　note　concordant？　Their　relation　according　to　a　commensurate



numerical　ratio。'　'Are　the　high　and　the　low　note　concordant？'　is



equivalent　to　'Is　their　ratio　commensurate？'；　and　when　we　find　that　it



is　commensurate；　we　ask　'What；　then；　is　their　ratio？'。



　　Cases　in　which　the　'middle'　is　sensible　show　that　the　object　of



our　inquiry　is　always　the　'middle'：　we　inquire；　because　we　have　not



perceived　it；　whether　there　is　or　is　not　a　'middle'　causing；　e。g。　an



eclipse。　On　the　other　hand；　if　we　were　on　the　moon　we　should　not　be



inquiring　either　as　to　the　fact　or　the　reason；　but　both　fact　and



reason　would　be　obvious　simultaneously。　For　the　act　of　perception



would　have　enabled　us　to　know　the　universal　too；　since；　the　present



fact　of　an　eclipse　being　evident；　perception　would　then　at　the　same



time　give　us　the　present　fact　of　the　earth's　screening　the　sun's



light；　and　from　this　would　arise　the　universal。



　　Thus；　as　we　maintain；　to　know　a　thing's　nature　is　to　know　the　reason



why　it　is；　and　this　is　equally　true　of　things　in　so　fa