the critique of pure reason- 第4部分

experiment　with　regard　to　the　intuition　of　objects。　If　the　intuition

must　conform　to　the　nature　of　the　objects；　I　do　not　see　how　we　can

know　anything　of　them　a　priori。　If；　on　the　other　hand；　the　object

conforms　to　the　nature　of　our　faculty　of　intuition；　I　can　then

easily　conceive　the　possibility　of　such　an　a　priori　knowledge。　Now

as　I　cannot　rest　in　the　mere　intuitions；　but…　if　they　are　to　become

cognitions…　must　refer　them；　as　representations；　to　something；　as

object；　and　must　determine　the　latter　by　means　of　the　former；　here

again　there　are　two　courses　open　to　me。　Either；　first；　I　may　assume

that　the　conceptions；　by　which　I　effect　this　determination；　conform　to

the　object…　and　in　this　case　I　am　reduced　to　the　same　perplexity　as

before；　or　secondly；　I　may　assume　that　the　objects；　or；　which　is　the

same　thing；　that　experience；　in　which　alone　as　given　objects　they

are　cognized；　conform　to　my　conceptions…　and　then　I　am　at　no　loss

how　to　proceed。　For　experience　itself　is　a　mode　of　cognition　which

requires　understanding。　Before　objects；　are　given　to　me；　that　is；　a

priori；　I　must　presuppose　in　myself　laws　of　the　understanding　which

are　expressed　in　conceptions　a　priori。　To　these　conceptions；　then；　all

the　objects　of　experience　must　necessarily　conform。　Now　there　are

objects　which　reason　thinks；　and　that　necessarily；　but　which　cannot　be

given　in　experience；　or；　at　least；　cannot　be　given　so　as　reason　thinks

them。　The　attempt　to　think　these　objects　will　hereafter　furnish　an

excellent　test　of　the　new　method　of　thought　which　we　have　adopted；　and

which　is　based　on　the　principle　that　we　only　cognize　in　things　a

priori　that　which　we　ourselves　place　in　them。*



　　*This　method；　accordingly；　which　we　have　borrowed　from　the　natural

philosopher；　consists　in　seeking　for　the　elements　of　pure　reason　in

that　which　admits　of　confirmation　or　refutation　by　experiment。　Now　the

propositions　of　pure　reason；　especially　when　they　transcend　the　limits

of　possible　experience；　do　not　admit　of　our　making　any　experiment　with

their　objects；　as　in　natural　science。　Hence；　with　regard　to　those

conceptions　and　principles　which　we　assume　a　priori；　our　only　course

ill　be　to　view　them　from　two　different　sides。　We　must　regard　one　and

the　same　conception；　on　the　one　hand；　in　relation　to　experience　as

an　object　of　the　senses　and　of　the　understanding；　on　the　other　hand；

in　relation　to　reason；　isolated　and　transcending　the　limits　of

experience；　as　an　object　of　mere　thought。　Now　if　we　find　that；　when　we

regard　things　from　this　double　point　of　view；　the　result　is　in　harmony

with　the　principle　of　pure　reason；　but　that；　when　we　regard　them

from　a　single　point　of　view；　reason　is　involved　in　self…contradiction；

then　the　experiment　will　establish　the　correctness　of　this

distinction。



　　This　attempt　succeeds　as　well　as　we　could　desire；　and　promises　to

metaphysics；　in　its　first　part…　that　is；　where　it　is　occupied　with

conceptions　a　priori；　of　which　the　corresponding　objects　may　be

given　in　experience…　the　certain　course　of　science。　For　by　this　new

method　we　are　enabled　perfectly　to　explain　the　possibility　of　a　priori

cognition；　and；　what　is　more；　to　demonstrate　satisfactorily　the　laws

which　lie　a　priori　at　the　foundation　of　nature；　as　the　sum　of　the

objects　of　experience…　neither　of　which　was　possible　according　to

the　procedure　hitherto　followed。　But　from　this　deduction　of　the

faculty　of　a　priori　cognition　in　the　first　part　of　metaphysics；　we

derive　a　surprising　result；　and　one　which；　to　all　appearance；

militates　against　the　great　end　of　metaphysics；　as　treated　in　the

second　part。　For　we　come　to　the　conclusion　that　our　faculty　of

cognition　is　unable　to　transcend　the　limits　of　possible　experience；

and　yet　this　is　precisely　the　most　essential　object　of　this　science。

The　estimate　of　our　rational　cognition　a　priori　at　which　we　arrive

is　that　it　has　only　to　do　with　phenomena；　and　that　things　in

themselves；　while　possessing　a　real　existence；　lie　beyond　its

sphere。　Here　we　are　enabled　to　put　the　justice　of　this　estimate　to　the

test。　For　that　which　of　necessity　impels　us　to　transcend　the　limits　of

experience　and　of　all　phenomena　is　the　unconditioned；　which　reason

absolutely　requires　in　things　as　they　are　in　themselves；　in　order　to

complete　the　series　of　conditions。　Now；　if　it　appears　that　when；　on

the　one　hand；　we　assume　that　our　cognition　conforms　to　its　objects

as　things　in　themselves；　the　unconditioned　cannot　be　thought　without

contradiction；　and　that　when；　on　the　other　hand；　we　assume　that　our

representation　of　things　as　they　are　given　to　us；　does　not　conform

to　these　things　as　they　are　in　themselves；　but　that　these　objects；

as　phenomena；　conform　to　our　mode　of　representation；　the　contradiction

disappears：　we　shall　then　be　convinced　of　the　truth　of　that　which　we

began　by　assuming　for　the　sake　of　experiment；　we　may　look　upon　it　as

established　that　the　unconditioned　does　not　lie　in　things　as　we　know

them；　or　as　they　are　given　to　us；　but　in　things　as　they　are　in

themselves；　beyond　the　range　of　our　cognition。*



　　*This　experiment　of　pure　reason　has　a　great　similarity　to　that　of

the　chemists；　which　they　term　the　experiment　of　reduction；　or；　more

usually；　the　synthetic　process。　The　analysis　of　the　metaphysician

separates　pure　cognition　a　priori　into　two　heterogeneous　elements；

viz。；　the　cognition　of　things　as　phenomena；　and　of　things　in

themselves。　Dialectic　combines　these　again　into　harmony　with　the

necessary　rational　idea　of　the　unconditioned；　and　finds　that　this

harmony　never　results　except　through　the　above　distinction；　which

is；　therefore；　concluded　to　be　just。



　　But；　after　we　have　thus　denied　the　power　of　speculative　reason　to

make　any　progress　in　the　sphere　of　the　supersensible；　it　still　remains

for　our　consideration　whether　data　do　not　exist　in　practical　cognition

which　may　enable　us　to　determine　the　transcendent　conception　of　the

unconditioned；　to　rise　beyond　the　limits　of　all　possible　experience

from　a　practical　point　of　view；　and　thus　to　satisfy　the　great　ends

of　metaphysics。　Speculative　reason　has　thus；　at　least；　made　room　for

such　an　extension　of　our　knowledge：　and；　if　it　must　leave　this　space

vacant；　still　it　does　not　rob　us　of　the　liberty　to　fill　it　up；　if　we

can；　by　means　of　practical　data…　nay；　it　even　challenges　us　to　make

the　attempt。*



　　*So　the　central　laws　of　the　movements　of　the　heavenly　bodies

established　the　truth　of　that　which　Copernicus；　first；　assumed　only　as

a　hypothesis；　and；　at　the　same　time；　brought　to　light　that　invisible

force　（Newtonian　attraction）　which　holds　the　universe　together。　The

latter　would　have　remained　forever　undiscovered；　if　Copernicus　had　not

ventured　on　the　experiment…　contrary　to　the　senses　but　still　just…

of　looking　for　the　observed　movements　not　in　the　heavenly　bodies；

but　in　the　spectator。　In　this　Preface　I　treat　the　new　metaphysical

method　as　a　hypothesis　with　the　view　of　rendering　apparent　the　first

attempts　at　such　a　change　of　method；　which　are　always　hypothetical。

But　in　the　Critique　itself　it　will　be　demonstrated；　not

hypothetically；　but　apodeictically；　from　the　nature　of　our

representations　of　space　and　time。　and　from　the　elementary　conceptions

of　the　understanding。



　　This　attempt　to　introduce　a　complete　revolution　in　the　procedure

of　metaphysics；　after　the　example　of　the　geometricians　and　natural

philosophers；　constitutes　the　aim　of　the　Critique　of　Pure

Speculative　Reason。　It　is　a　treatise　on　the　method　to　be　followed；　not

a　system　of　the　science　itself。　But；　at　the　same　time；　it　marks　out

and　defines　both　the　external　boundaries　and　the　internal　structure　of

this　science。　For　pure　speculative　reason　has　this　peculiarity；

that；　in　choosing　the　various　objects　of　thought；　it　is　able　to　define

the　limits　of　its　own　faculties；　and　even　to　give　a　complete

enumeration　of　the　possible　modes　of　proposing　problems　to　itself；　and

thus　to　sketch　out　the　entire　system　of　metaphysics。　For；　on　the　one

hand；　in　cognition　a　priori；　nothing　must　be　attributed　to　the　objects

but　what　the　thinking　subject　derives　from　itself；　and；　on　the　other

hand；　reason　is；　in　regard　to　the　principles　of　cognition；　a　perfectly

distinct；　independent　unity；　in　which；　as　in　an　organized　body；

every　member　exists　for　the　sake　of　the　others；　and　all　for　the　sake

of　each；　so　that　no　principle　can　be　viewed；　with　safety；　in　one

relationship；　unless　it　is；　at　the　same　time；　viewed　in　relation　to

the　total　use　of　pure　reason。　Hence；　too；　metaphysics　has　this

singular　advantage…　an　advantage　which　falls　to　the　lot　of　no　other

science　which　has　to　do　with　objects…　that；　if　once　it　is　conducted

into　the　sure　path　of　science；　by　means　of　this　criticism；　it　can　then

take　in　the　whole　sphere　of　its　cognitions；　and　can　thus　complete

its　work；　and　leave　it　for　the　use　of　posterity；　as　a　capital　which

can　never　receive　fresh　accessions。　For　metaphysics　has　to　deal　only

with　principles　and　with　the　limitations　of　its　own　employment　as

determined　by　these　principles。　To　this　perfection　it　is；　therefore；

bound；　as　the　fundamental　science；　to　attain；　and　to　it　the　maxim

may　justly　be　applied：



　　　　Nil　actum　reputans；　si　quid　superesset　agendum。*



　　*〃He　considered　nothing　done；　so　long　as　anything　remained　to　be

done。〃



　　But；　it　will　be　asked；　what　kind　of　a　treasure　is　this　that　we

propose　to　bequeath　to　posterity？　What　is　the　real　value　of　this

system　of　metaphysics；　purified　by　criticism；　and　thereby　reduced　to　a

permanent　condition？　A　cursory　view　of　the　present　work　will　lead　to

the　supposition　that　its　use　is　merely　negative；　that　it　only　serves

to　warn　us　against　venturing；　with　speculative　reason；　beyond　the

limits　of　experience。　This　is；　in　fact；　its　primary　use。　But　this；

at　once；　assumes　a　positive　value；　when　we　observe　that　the　principles

with　which　speculative　reason　endeavours　to　transcend　its　limits

lead　inevita