the critique of pure reason- 第118部分

something　（the　sun's　heat）　preceding；　which　this　law；　although；

without　the　aid　of　experience；　I　could　not　cognize　a　priori　and　in　a

determinate　manner　either　the　cause　from　the　effect；　or　the　effect

from　the　cause。　Hume　was；　therefore；　wrong　in　inferring；　from　the

contingency　of　the　determination　according　to　law；　the　contingency

of　the　law　itself；　and　the　passing　beyond　the　conception　of　a　thing　to

possible　experience　（which　is　an　a　priori　proceeding；　constituting　the

objective　reality　of　the　conception）；　he　confounded　with　our　synthesis

of　objects　in　actual　experience；　which　is　always；　of　course；

empirical。　Thus；　too；　he　regarded　the　principle　of　affinity；　which　has

its　seat　in　the　understanding　and　indicates　a　necessary　connection；　as

a　mere　rule　of　association；　lying　in　the　imitative　faculty　of

imagination；　which　can　present　only　contingent；　and　not　objective

connections。

　　The　sceptical　errors　of　this　remarkably　acute　thinker　arose

principally　from　a　defect；　which　was　common　to　him　with　the

dogmatists；　namely；　that　he　had　never　made　a　systematic　review　of

all　the　different　kinds　of　a　priori　synthesis　performed　by　the

understanding。　Had　he　done　so；　he　would　have　found；　to　take　one

example　among　many；　that　the　principle　of　permanence　was　of　this

character；　and　that　it；　as　well　as　the　principle　of　causality；

anticipates　experience。　In　this　way　he　might　have　been　able　to

describe　the　determinate　limits　of　the　a　priori　operations　of

understanding　and　reason。　But　he　merely　declared　the　understanding

to　be　limited；　instead　of　showing　what　its　limits　were；　he　created　a

general　mistrust　in　the　power　of　our　faculties；　without　giving　us

any　determinate　knowledge　of　the　bounds　of　our　necessary　and

unavoidable　ignorance；　he　examined　and　condemned　some　of　the

principles　of　the　understanding；　without　investigating　all　its

powers　with　the　completeness　necessary　to　criticism。　He　denies；　with

truth；　certain　powers　to　the　understanding；　but　he　goes　further；　and

declares　it　to　be　utterly　inadequate　to　the　a　priori　extension　of

knowledge；　although　he　has　not　fully　examined　all　the　powers　which

reside　in　the　faculty；　and　thus　the　fate　which　always　overtakes

scepticism　meets　him　too。　That　is　to　say；　his　own　declarations　are

doubted；　for　his　objections　were　based　upon　facta；　which　are

contingent；　and　not　upon　principles；　which　can　alone　demonstrate　the

necessary　invalidity　of　all　dogmatical　assertions。

　　As　Hume　makes　no　distinction　between　the　well…grounded　claims　of　the

understanding　and　the　dialectical　pretensions　of　reason；　against

which；　however；　his　attacks　are　mainly　directed；　reason　does　not

feel　itself　shut　out　from　all　attempts　at　the　extension　of　a　priori

cognition；　and　hence　it　refuses；　in　spite　of　a　few　checks　in　this　or

that　quarter；　to　relinquish　such　efforts。　For　one　naturally　arms

oneself　to　resist　an　attack；　and　becomes　more　obstinate　in　the　resolve

to　establish　the　claims　he　has　advanced。　But　a　complete　review　of

the　powers　of　reason；　and　the　conviction　thence　arising　that　we　are　in

possession　of　a　limited　field　of　action；　while　we　must　admit　the

vanity　of　higher　claims；　puts　an　end　to　all　doubt　and　dispute；　and

induces　reason　to　rest　satisfied　with　the　undisturbed　possession　of

its　limited　domain。

　　To　the　uncritical　dogmatist；　who　has　not　surveyed　the　sphere　of

his　understanding；　nor　determined；　in　accordance　with　principles；

the　limits　of　possible　cognition；　who；　consequently；　is　ignorant　of

his　own　powers；　and　believes　he　will　discover　them　by　the　attempts

he　makes　in　the　field　of　cognition；　these　attacks　of　scepticism　are

not　only　dangerous；　but　destructive。　For　if　there　is　one　proposition

in　his　chain　of　reasoning　which　be　he　cannot　prove；　or　the　fallacy

in　which　be　cannot　evolve　in　accordance　with　a　principle；　suspicion

falls　on　all　his　statements；　however　plausible　they　may　appear。

　　And　thus　scepticism；　the　bane　of　dogmatical　philosophy；　conducts

us　to　a　sound　investigation　into　the　understanding　and　the　reason。

When　we　are　thus　far　advanced；　we　need　fear　no　further

attacks；　for　the　limits　of　our　domain　are　clearly　marked　out；　and　we

can　make　no　claims　nor　become　involved　in　any　disputes　regarding　the

region　that　lies　beyond　these　limits。　Thus　the　sceptical　procedure

in　philosophy　does　not　present　any　solution　of　the　problems　of　reason；

but　it　forms　an　excellent　exercise　for　its　powers；　awakening　its

circumspection；　and　indicating　the　means　whereby　it　may　most　fully

establish　its　claims　to　its　legitimate　possessions。



　　　　SECTION　III。　The　Discipline　of　Pure　Reason　in　Hypothesis。



　　This　critique　of　reason　has　now　taught　us　that　all　its　efforts　to

extend　the　bounds　of　knowledge；　by　means　of　pure　speculation；　are

utterly　fruitless。　So　much　the　wider　field；　it　may　appear；　lies　open

to　hypothesis；　as；　where　we　cannot　know　with　certainty；　we　are　at

liberty　to　make　guesses　and　to　form　suppositions。

　　Imagination　may　be　allowed；　under　the　strict　surveillance　of　reason；

to　invent　suppositions；　but；　these　must　be　based　on　something　that

is　perfectly　certain…　and　that　is　the　possibility　of　the　object。　If　we

are　well　assured　upon　this　point；　it　is　allowable　to　have　recourse

to　supposition　in　regard　to　the　reality　of　the　object；　but　this

supposition　must；　unless　it　is　utterly　groundless；　be　connected；　as

its　ground　of　explanation；　with　that　which　is　really　given　and

absolutely　certain。　Such　a　supposition　is　termed　a　hypothesis。

　　It　is　beyond　our　power　to　form　the　least　conception　a　priori　of

the　possibility　of　dynamical　connection　in　phenomena；　and　the　category

of　the　pure　understanding　will　not　enable　us　to　ex。　cogitate　any

such　connection；　but　merely　helps　us　to　understand　it；　when　we　meet

with　it　in　experience。　For　this　reason　we　cannot；　in　accordance　with

the　categories；　imagine　or　invent　any　object　or　any　property　of　an

object　not　given；　or　that　may　not　be　given　in　experience；　and　employ

it　in　a　hypothesis；　otherwise；　we　should　be　basing　our　chain　of

reasoning　upon　mere　chimerical　fancies；　and　not　upon　conceptions　of

things。　Thus；　we　have　no　right　to　assume　the　existence　of　new

powers；　not　existing　in　nature…　for　example；　an　understanding　with　a

non…sensuous　intuition；　a　force　of　attraction　without　contact；　or　some

new　kind　of　substances　occupying　space；　and　yet　without　the　property

of　impenetrability…　and；　consequently；　we　cannot　assume　that　there

is　any　other　kind　of　community　among　substances　than　that　observable

in　experience；　any　kind　of　presence　than　that　in　space；　or　any　kind　of

duration　than　that　in　time。　In　one　word；　the　conditions　of　possible

experience　are　for　reason　the　only　conditions　of　the　possibility　of

things；　reason　cannot　venture　to　form；　independently　of　these

conditions；　any　conceptions　of　things；　because　such　conceptions；

although　not　self…contradictory；　are　without　object　and　without

application。

　　The　conceptions　of　reason　are；　as　we　have　already　shown；　mere　ideas；

and　do　not　relate　to　any　object　in　any　kind　of　experience。　At　the　same

time；　they　do　not　indicate　imaginary　or　possible　objects。　They　are

purely　problematical　in　their　nature　and；　as　aids　to　the　heuristic

exercise　of　the　faculties；　form　the　basis　of　the　regulative　principles

for　the　systematic　employment　of　the　understanding　in　the　field　of

experience。　If　we　leave　this　ground　of　experience；　they　become　mere

fictions　of　thought；　the　possibility　of　which　is　quite　indemonstrable；

and　they　cannot；　consequently；　be　employed　as　hypotheses　in　the

explanation　of　real　phenomena。　It　is　quite　admissible　to　cogitate

the　soul　as　simple；　for　the　purpose　of　enabling　ourselves　to　employ

the　idea　of　a　perfect　and　necessary　unity　of　all　the　faculties　of

the　mind　as　the　principle　of　all　our　inquiries　into　its　internal

phenomena；　although　we　cannot　cognize　this　unity　in　concreto。　But　to

assume　that　the　soul　is　a　simple　substance　（a　transcendental

conception）　would　be　enouncing　a　proposition　which　is　not　only

indemonstrable…　as　many　physical　hypotheses　are…　but　a　proposition

which　is　purely　arbitrary；　and　in　the　highest　degree　rash。　The

simple　is　never　presented　in　experience；　and；　if　by　substance　is

here　meant　the　permanent　object　of　sensuous　intuition；　the　possibility

of　a　simple　phenomenon　is　perfectly　inconceivable。　Reason　affords　no

good　grounds　for　admitting　the　existence　of　intelligible　beings；　or　of

intelligible　properties　of　sensuous　things；　although…　as　we　have　no

conception　either　of　their　possibility　or　of　their　impossibility…　it

will　always　be　out　of　our　power　to　affirm　dogmatically　that　they　do

not　exist。　In　the　explanation　of　given　phenomena；　no　other　things

and　no　other　grounds　of　explanation　can　be　employed　than　those　which

stand　in　connection　with　the　given　phenomena　according　to　the　known

laws　of　experience。　A　transcendental　hypothesis；　in　which　a　mere

idea　of　reason　is　employed　to　explain　the　phenomena　of　nature；　would

not　give　us　any　better　insight　into　a　phenomenon；　as　we　should　be

trying　to　explain　what　we　do　not　sufficiently　understand　from　known

empirical　principles；　by　what　we　do　not　understand　at　all。　The

principles　of　such　a　hypothesis　might　conduce　to　the　satisfaction　of

reason；　but　it　would　not　assist　the　understanding　in　its　application

to　objects。　Order　and　conformity　to　aims　in　the　sphere　of　nature

must　be　themselves　explained　upon　natural　grounds　and　according　to

natural　laws；　and　the　wildest　hypotheses；　if　they　are　only　physical；

are　here　more　admissible　than　a　hyperphysical　hypothesis；　such　as　that

of　a　divine　author。　For　such　a　hypothesis　would　introduce　the

principle　of　ignava　ratio；　which　requires　us　to　give　up　the　search　for

causes　that　might　be　discovered　in　the　course　of　experience　and　to

rest　satisfied　with　a　mere　idea。　As　regards　the　absolute　totality　of

the　grounds　of　explanation　in　the　series　of　these　causes；　this　can

be　no　hindrance　to　the　understanding　in　the　case　of　phenomena；