the critique of pure reason- 第2部分

everything　which　bears　the　least　semblance　of　an　hypothesis　must　be

excluded；　as　of　no　value　in　such　discussions。　For　it　is　a　necessary

condition　of　every　cognition　that　is　to　be　established　upon　a　priori

grounds　that　it　shall　be　held　to　be　absolutely　necessary；　much　more　is

this　the　case　with　an　attempt　to　determine　all　pure　a　priori

cognition；　and　to　furnish　the　standard…　and　consequently　an　example…

of　all　apodeictic　（philosophical）　certitude。　Whether　I　have

succeeded　in　what　I　professed　to　do；　it　is　for　the　reader　to

determine；　it　is　the　author's　business　merely　to　adduce　grounds　and

reasons；　without　determining　what　influence　these　ought　to　have　on　the

mind　of　his　judges。　But；　lest　anything　he　may　have　said　may　become　the

innocent　cause　of　doubt　in　their　minds；　or　tend　to　weaken　the　effect

which　his　arguments　might　otherwise　produce…　he　may　be　allowed　to

point　out　those　passages　which　may　occasion　mistrust　or　difficulty；

although　these　do　not　concern　the　main　purpose　of　the　present　work。　He

does　this　solely　with　the　view　of　removing　from　the　mind　of　the　reader

any　doubts　which　might　affect　his　judgement　of　the　work　as　a　whole；

and　in　regard　to　its　ultimate　aim。

　　I　know　no　investigations　more　necessary　for　a　full　insight　into

the　nature　of　the　faculty　which　we　call　understanding；　and　at　the　same

time　for　the　determination　of　the　rules　and　limits　of　its　use；　than

those　undertaken　in　the　second　chapter　of　the　〃Transcendental

Analytic；〃　under　the　title　of　〃Deduction　of　the　Pure　Conceptions　of

the　Understanding〃；　and　they　have　also　cost　me　by　far　the　greatest

labour…　labour　which；　I　hope；　will　not　remain　uncompensated。　The

view　there　taken；　which　goes　somewhat　deeply　into　the　subject；　has　two

sides；　The　one　relates　to　the　objects　of　the　pure　understanding；　and

is　intended　to　demonstrate　and　to　render　comprehensible　the

objective　validity　of　its　a　priori　conceptions；　and　it　forms　for

this　reason　an　essential　part　of　the　Critique。　The　other　considers　the

pure　understanding　itself；　its　possibility　and　its　powers　of

cognition…　that　is；　from　a　subjective　point　of　view；　and；　although

this　exposition　is　of　great　importance；　it　does　not　belong　essentially

to　the　main　purpose　of　the　work；　because　the　grand　question　is　what

and　how　much　can　reason　and　understanding；　apart　from　experience；

cognize；　and　not；　how　is　the　faculty　of　thought　itself　possible？　As

the　latter　is　an；　inquiry　into　the　cause　of　a　given　effect；　and　has

thus　in　it　some　semblance　of　an　hypothesis　（although；　as　I　shall

show　on　another　occasion；　this　is　really　not　the　fact）；　it　would

seem　that；　in　the　present　instance；　I　had　allowed　myself　to　enounce

a　mere　opinion；　and　that　the　reader　must　therefore　be　at　liberty　to

hold　a　different　opinion。　But　I　beg　to　remind　him　that；　if　my

subjective　deduction　does　not　produce　in　his　mind　the　conviction　of

its　certitude　at　which　I　aimed；　the　objective　deduction；　with　which

alone　the　present　work　is　properly　concerned；　is　in　every　respect

satisfactory。

　　As　regards　clearness；　the　reader　has　a　right　to　demand；　in　the　first

place；　discursive　or　logical　clearness；　that　is；　on　the　basis　of

conceptions；　and；　secondly；　intuitive　or　aesthetic　clearness；　by　means

of　intuitions；　that　is；　by　examples　or　other　modes　of　illustration

in　concreto。　I　have　done　what　I　could　for　the　first　kind　of

intelligibility。　This　was　essential　to　my　purpose；　and　it　thus

became　the　accidental　cause　of　my　inability　to　do　complete　justice

to　the　second　requirement。　I　have　been　almost　always　at　a　loss；　during

the　progress　of　this　work；　how　to　settle　this　question。　Examples　and

illustrations　always　appeared　to　me　necessary；　and；　in　the　first

sketch　of　the　Critique；　naturally　fell　into　their　proper　places。　But　I

very　soon　became　aware　of　the　magnitude　of　my　task；　and　the　numerous

problems　with　which　I　should　be　engaged；　and；　as　I　perceived　that　this

critical　investigation　would；　even　if　delivered　in　the　driest

scholastic　manner；　be　far　from　being　brief；　I　found　it　unadvisable

to　enlarge　it　still　more　with　examples　and　explanations；　which　are

necessary　only　from　a　popular　point　of　view。　I　was　induced　to　take

this　course　from　the　consideration　also　that　the　present　work　is　not

intended　for　popular　use；　that　those　devoted　to　science　do　not　require

such　helps；　although　they　are　always　acceptable；　and　that　they　would

have　materially　interfered　with　my　present　purpose。　Abbe　Terrasson

remarks　with　great　justice　that；　if　we　estimate　the　size　of　a　work；

not　from　the　number　of　its　pages；　but　from　the　time　which　we　require

to　make　ourselves　master　of　it；　it　may　be　said　of　many　a　book　that

it　would　be　much　shorter；　if　it　were　not　so　short。　On　the　other

hand；　as　regards　the　comprehensibility　of　a　system　of　speculative

cognition；　connected　under　a　single　principle；　we　may　say　with　equal

justice：　many　a　book　would　have　been　much　clearer；　if　it　had　not

been　intended　to　be　so　very　clear。　For　explanations　and　examples；

and　other　helps　to　intelligibility；　aid　us　in　the　comprehension　of

parts；　but　they　distract　the　attention；　dissipate　the　mental　power

of　the　reader；　and　stand　in　the　way　of　his　forming　a　clear

conception　of　the　whole；　as　he　cannot　attain　soon　enough　to　a　survey

of　the　system；　and　the　colouring　and　embellishments　bestowed　upon　it

prevent　his　observing　its　articulation　or　organization…　which　is　the

most　important　consideration　with　him；　when　he　comes　to　judge　of　its

unity　and　stability。

　　The　reader　must　naturally　have　a　strong　inducement　to　co…operate

with　the　present　author；　if　he　has　formed　the　intention　of　erecting

a　complete　and　solid　edifice　of　metaphysical　science；　according　to　the

plan　now　laid　before　him。　Metaphysics；　as　here　represented；　is　the

only　science　which　admits　of　completion…　and　with　little　labour；　if　it

is　united；　in　a　short　time；　so　that　nothing　will　be　left　to　future

generations　except　the　task　of　illustrating　and　applying　it

didactically。　For　this　science　is　nothing　more　than　the　inventory　of

all　that　is　given　us　by　pure　reason；　systematically　arranged。

Nothing　can　escape　our　notice；　for　what　reason　produces　from　itself

cannot　lie　concealed；　but　must　be　brought　to　the　light　by　reason

itself；　so　soon　as　we　have　discovered　the　common　principle　of　the

ideas　we　seek。　The　perfect　unity　of　this　kind　of　cognitions；　which　are

based　upon　pure　conceptions；　and　uninfluenced　by　any　empirical

element；　or　any　peculiar　intuition　leading　to　determinate

experience；　renders　this　completeness　not　only　practicable；　but　also

necessary。



　　　　　Tecum　habita；　et　noris　quam　sit　tibi　curta　supellex。*



　　*Persius。　＇Satirae　iv。　52。　〃Dwell　with　yourself；　and　you　will　know

how　short　your　household　stuff　is。〃



　　Such　a　system　of　pure　speculative　reason　I　hope　to　be　able　to

publish　under　the　title　of　Metaphysic　of　Nature。　The　content　of　this

work　（which　will　not　be　half　so　long）　will　be　very　much　richer　than

that　of　the　present　Critique；　which　has　to　discover　the　sources　of

this　cognition　and　expose　the　conditions　of　its　possibility；　and　at

the　same　time　to　clear　and　level　a　fit　foundation　for　the　scientific

edifice。　In　the　present　work；　I　look　for　the　patient　hearing　and　the

impartiality　of　a　judge；　in　the　other；　for　the　good…will　and

assistance　of　a　co…labourer。　For；　however　complete　the　list　of

principles　for　this　system　may　be　in　the　Critique；　the　correctness

of　the　system　requires　that　no　deduced　conceptions　should　be　absent。

These　cannot　be　presented　a　priori；　but　must　be　gradually

discovered；　and；　while　the　synthesis　of　conceptions　has　been　fully

exhausted　in　the　Critique；　it　is　necessary　that；　in　the　proposed　work；

the　same　should　be　the　case　with　their　analysis。　But　this　will　be

rather　an　amusement　than　a　labour。

　　　　　　　　　　　　　PREFACE　TO　THE　SECOND　EDITION；　1787



　　Whether　the　treatment　of　that　portion　of　our　knowledge　which　lies

within　the　province　of　pure　reason　advances　with　that　undeviating

certainty　which　characterizes　the　progress　of　science；　we　shall　be

at　no　loss　to　determine。　If　we　find　those　who　are　engaged　in

metaphysical　pursuits；　unable　to　come　to　an　understanding　as　to　the

method　which　they　ought　to　follow；　if　we　find　them；　after　the　most

elaborate　preparations；　invariably　brought　to　a　stand　before　the

goal　is　reached；　and　compelled　to　retrace　their　steps　and　strike

into　fresh　paths；　we　may　then　feel　quite　sure　that　they　are　far　from

having　attained　to　the　certainty　of　scientific　progress　and　may　rather

be　said　to　be　merely　groping　about　in　the　dark。　In　these　circumstances

we　shall　render　an　important　service　to　reason　if　we　succeed　in　simply

indicating　the　path　along　which　it　must　travel；　in　order　to　arrive

at　any　results…　even　if　it　should　be　found　necessary　to　abandon　many

of　those　aims　which；　without　reflection；　have　been　proposed　for　its

attainment。

　　That　logic　has　advanced　in　this　sure　course；　even　from　the

earliest　times；　is　apparent　from　the　fact　that；　since　Aristotle；　it

has　been　unable　to　advance　a　step　and；　thus；　to　all　appearance　has

reached　its　completion。　For；　if　some　of　the　moderns　have　thought　to

enlarge　its　domain　by　introducing　psychological　discussions　on　the

mental　faculties；　such　as　imagination　and　wit；　metaphysical；

discussions　on　the　origin　of　knowledge　and　the　different　kinds　of

certitude；　according　to　the　difference　of　the　objects　（idealism；

scepticism；　and　so　on）；　or　anthropological　discussions　on

prejudices；　their　causes　and　remedies：　this　attempt；　on　the　part　of

these　authors；　only　shows　their　ignorance　of　the　peculiar　nature　of

logical　science。　We　do　not　enlarge　but　disfigure　the　sciences　when

we　lose　sight　of　their　respective　limits　and　allow　them　to　run　into

one　another。　Now　logic　is　enclosed　within　limits　which　admit　of

perfectly　clear　definition；　it　is　a　science　which　has　for　its　object

nothing　but　the　exposition　and　proof　of　the　formal　laws　of　all

thought；　whether　it　be　a　priori