the critique of pure reason-第37节

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conditions　under　which　alone　the　transcendental　faculty　of　judgement

is　justified　in　using　the　pure　conceptions　of　the　understanding　for

synthetical　judgements。　Our　duty　at　present　is　to　exhibit　in

systematic　connection　those　judgements　which　the　understanding

really　produces　a　priori。　For　this　purpose；　our　table　of　the

categories　will　certainly　afford　us　the　natural　and　safe　guidance。　For

it　is　precisely　the　categories　whose　application　to　possible

experience　must　constitute　all　pure　a　priori　cognition　of　the

understanding；　and　the　relation　of　which　to　sensibility　will；　on

that　very　account；　present　us　with　a　complete　and　systematic　catalogue

of　all　the　transcendental　principles　of　the　use　of　the　understanding。

　　Principles　a　priori　are　so　called；　not　merely　because　they　contain

in　themselves　the　grounds　of　other　judgements；　but　also　because　they

themselves　are　not　grounded　in　higher　and　more　general　cognitions。

This　peculiarity；　however；　does　not　raise　them　altogether　above　the

need　of　a　proof。　For　although　there　could　be　found　no　higher

cognition；　and　therefore　no　objective　proof；　and　although　such　a

principle　rather　serves　as　the　foundation　for　all　cognition　of　the

object；　this　by　no　means　hinders　us　from　drawing　a　proof　from　the

subjective　sources　of　the　possibility　of　the　cognition　of　an　object。

Such　a　proof　is　necessary；　moreover；　because　without　it　the

principle　might　be　liable　to　the　imputation　of　being　a　mere　gratuitous

assertion。

　　In　the　second　place；　we　shall　limit　our　investigations　to　those

principles　which　relate　to　the　categories。　For　as　to　the　principles　of

transcendental　aesthetic；　according　to　which　space　and　time　are　the

conditions　of　the　possibility　of　things　as　phenomena；　as　also　the

restriction　of　these　principles；　namely；　that　they　cannot　be　applied

to　objects　as　things　in　themselves…　these；　of　course；　do　not　fall

within　the　scope　of　our　present　inquiry。　In　like　manner；　the

principles　of　mathematical　science　form　no　part　of　this　system；

because　they　are　all　drawn　from　intuition；　and　not　from　the　pure

conception　of　the　understanding。　The　possibility　of　these

principles；　however；　will　necessarily　be　considered　here；　inasmuch

as　they　are　synthetical　judgements　a　priori；　not　indeed　for　the

purpose　of　proving　their　accuracy　and　apodeictic　certainty；　which　is

unnecessary；　but　merely　to　render　conceivable　and　deduce　the

possibility　of　such　evident　a　priori　cognitions。

　　But　we　shall　have　also　to　speak　of　the　principle　of　analytical

judgements；　in　opposition　to　synthetical　judgements；　which　is　the

proper　subject　of　our　inquiries；　because　this　very　opposition　will

free　the　theory　of　the　latter　from　all　ambiguity；　and　place　it　clearly

before　our　eyes　in　its　true　nature。



　　　　　　　　SYSTEM　OF　THE　PRINCIPLES　OF　THE　PURE　UNDERSTANDING。



　　SECTION　I。　Of　the　Supreme　Principle　of　all　Analytical　Judgements。



　　Whatever　may　be　the　content　of　our　cognition；　and　in　whatever　manner

our　cognition　may　be　related　to　its　object；　the　universal；　although

only　negative　conditions　of　all　our　judgements　is　that　they　do　not

contradict　themselves；　otherwise　these　judgements　are　in　themselves

（even　without　respect　to　the　object）　nothing。　But　although　there　may

exist　no　contradiction　in　our　judgement；　it　may　nevertheless　connect

conceptions　in　such　a　manner　that　they　do　not　correspond　to　the

object；　or　without　any　grounds　either　a　priori　or　a　posteriori　for

arriving　at　such　a　judgement；　and　thus；　without　being

self…contradictory；　a　judgement　may　nevertheless　be　either　false　or

groundless。

　　Now；　the　proposition：　〃No　subject　can　have　a　predicate　that

contradicts　it；〃　is　called　the　principle　of　contradiction；　and　is　a

universal　but　purely　negative　criterion　of　all　truth。　But　it　belongs

to　logic　alone；　because　it　is　valid　of　cognitions；　merely　as

cognitions　and　without　respect　to　their　content；　and　declares　that　the

contradiction　entirely　nullifies　them。　We　can　also；　however；　make　a

positive　use　of　this　principle；　that　is；　not　merely　to　banish

falsehood　and　error　（in　so　far　as　it　rests　upon　contradiction）；　but

also　for　the　cognition　of　truth。　For　if　the　judgement　is　analytical；

be　it　affirmative　or　negative；　its　truth　must　always　be　recognizable

by　means　of　the　principle　of　contradiction。　For　the　contrary　of　that

which　lies　and　is　cogitated　as　conception　in　the　cognition　of　the

object　will　be　always　properly　negatived；　but　the　conception　itself

must　always　be　affirmed　of　the　object；　inasmuch　as　the　contrary

thereof　would　be　in　contradiction　to　the　object。

　　We　must　therefore　hold　the　principle　of　contradiction　to　be　the

universal　and　fully　sufficient　Principle　of　all　analytical

cognition。　But　as　a　sufficient　criterion　of　truth；　it　has　no　further

utility　or　authority。　For　the　fact　that　no　cognition　can　be　at

variance　with　this　principle　without　nullifying　itself；　constitutes

this　principle　the　sine　qua　non；　but　not　the　determining　ground　of　the

truth　of　our　cognition。　As　our　business　at　present　is　properly　with

the　synthetical　part　of　our　knowledge　only；　we　shall　always　be　on

our　guard　not　to　transgress　this　inviolable　principle；　but　at　the　same

time　not　to　expect　from　it　any　direct　assistance　in　the

establishment　of　the　truth　of　any　synthetical　proposition。

　　There　exists；　however；　a　formula　of　this　celebrated　principle…　a

principle　merely　formal　and　entirely　without　content…　which　contains　a

synthesis　that　has　been　inadvertently　and　quite　unnecessarily　mixed　up

with　it。　It　is　this：　〃It　is　impossible　for　a　thing　to　be　and　not　to　be

at　the　same　time。〃　Not　to　mention　the　superfluousness　of　the

addition　of　the　word　impossible　to　indicate　the　apodeictic

certainty；　which　ought　to　be　self…evident　from　the　proposition　itself；

the　proposition　is　affected　by　the　condition　of　time；　and　as　it　were

says：　〃A　thing　=　A；　which　is　something　=　B；　cannot　at　the　same　time　be

non…B。〃　But　both；　B　as　well　as　non…B；　may　quite　well　exist　in

succession。　For　example；　a　man　who　is　young　cannot　at　the　same　time　be

old；　but　the　same　man　can　very　well　be　at　one　time　young；　and　at

another　not　young；　that　is；　old。　Now　the　principle　of　contradiction　as

a　merely　logical　proposition　must　not　by　any　means　limit　its

application　merely　to　relations　of　time；　and　consequently　a　formula

like　the　preceding　is　quite　foreign　to　its　true　purpose。　The

misunderstanding　arises　in　this　way。　We　first　of　all　separate　a

predicate　of　a　thing　from　the　conception　of　the　thing；　and

afterwards　connect　with　this　predicate　its　opposite；　and　hence　do

not　establish　any　contradiction　with　the　subject；　but　only　with　its

predicate；　which　has　been　conjoined　with　the　subject　synthetically…

a　contradiction；　moreover；　which　obtains　only　when　the　first　and

second　predicate　are　affirmed　in　the　same　time。　If　I　say：　〃A　man　who

is　ignorant　is　not　learned；〃　the　condition　〃at　the　same　time〃　must

be　added；　for　he　who　is　at　one　time　ignorant；　may　at　another　be

learned。　But　if　I　say：　〃No　ignorant　man　is　a　learned　man；〃　the

proposition　is　analytical；　because　the　characteristic　ignorance　is　now

a　constituent　part　of　the　conception　of　the　subject；　and　in　this

case　the　negative　proposition　is　evident　immediately　from　the

proposition　of　contradiction；　without　the　necessity　of　adding　the

condition　〃the　same　time。〃　This　is　the　reason　why　I　have　altered　the

formula　of　this　principle…　an　alteration　which　shows　very　clearly

the　nature　of　an　analytical　proposition。



　　SECTION　II。　Of　the　Supreme　Principle　of　all　Synthetical　Judgements。



　　The　explanation　of　the　possibility　of　synthetical　judgements　is　a

task　with　which　general　logic　has　nothing　to　do；　indeed　she　needs

not　even　be　acquainted　with　its　name。　But　in　transcendental　logic　it

is　the　most　important　matter　to　be　dealt　with…　indeed　the　only　one；　if

the　question　is　of　the　possibility　of　synthetical　judgements　a　priori；

the　conditions　and　extent　of　their　validity。　For　when　this　question　is

fully　decided；　it　can　reach　its　aim　with　perfect　ease；　the

determination；　to　wit；　of　the　extent　and　limits　of　the　pure

understanding。

　　In　an　analytical　judgement　I　do　not　go　beyond　the　given

conception；　in　order　to　arrive　at　some　decision　respecting　it。　If

the　judgement　is　affirmative；　I　predicate　of　the　conception　only

that　which　was　already　cogitated　in　it；　if　negative；　I　merely

exclude　from　the　conception　its　contrary。　But　in　synthetical

judgements；　I　must　go　beyond　the　given　conception；　in　order　to

cogitate；　in　relation　with　it；　something　quite　different　from　that

which　was　cogitated　in　it；　a　relation　which　is　consequently　never

one　either　of　identity　or　contradiction；　and　by　means　of　which　the

truth　or　error　of　the　judgement　cannot　be　discerned　merely　from　the

judgement　itself。

　　Granted；　then；　that　we　must　go　out　beyond　a　given　conception；　in

order　to　compare　it　synthetically　with　another；　a　third　thing　is

necessary；　in　which　alone　the　synthesis　of　two　conceptions　can