M ETAPHY S ICS, 
1>£'G 
vifion, (Critic, p. ^Co.') this confufion is avoided. But 
the utility of an accurate Table of the Categories appears 
Bill more evident, when we feparate, as will be immedi¬ 
ately done, the Table of the TranJ'eendental Conceptions of 
Rcofon , which are of a very different nature and origin, 
and confequently mud have a different form, from thole 
conceptions of Underftanding; which neceiTary repara¬ 
tion has never yet been performed in any fyftem of Me- 
taphyfics ; but on the contrary, the Ideas of Reefim have 
been confounded with the Conceptions of Underjlmuling, 
without any dillinftion, as if they were the children of 
one family ; a confulion which, for want of a complete 
fyftem of the Categories, was unavoidable. 
Third Tranfcendental Queftion. 
How an: Mdaphyfics in general pofilTc? 
Pure Mathematics and pure Natural Philofophy did 
not require, for their own fecurity, fuch a deduction as 
we have here given of them. For tfie Mathematics reft 
upon their own evidence; and Natural Philofophy, al¬ 
though it fprings from the pure fources of the underftand- 
ing, neverthelefs requires the confirmation of experience, 
the teftimony of which it can never difpenfe with, be- 
caule all its philofophical certainty, can never equal that 
of the Mathematics. Neither of thefe lciences ftand in 
need of this inveftigation on their own account, but 
merely for the fake of another fcience, namely Meta¬ 
physics. 
Metaphyfics treat of Cmurptions of Nature, as applied to 
experience, as well as of pure Conceptions of Reafon, which 
can never be found in any poftible experience ; confe¬ 
quently of Conceptions whole objective realky, and of 
affertions, whole Truth or Faifehood, is not confirmed or 
laid open by any experience. And this part of Meta¬ 
phyfics is precifely that which conftitutes their moft ef- 
fential objeft. This fcience then requires fuch a deduc¬ 
tion for its own Jane. Our prefent Queftion, therefore, 
goes to the very root of Metaphyfics, the occupation of 
reafon with itfelf, while it is employed in brooding over 
its own conceptions. This queftion concerns, therefore, 
that pretended acquaintance with objects which immedi¬ 
ately arifes, without requiring the mediation of experi¬ 
ence, and without the poffibility of its being conlirmed 
by experience. 
If we can fay that a fcience is at leaft fubjeftively real 
in every man’s mind, when it appears that the problems 
leading to it naturally occur to every human reafon, and 
that therefore many though faulty attempts towards its 
eftablilhment are unavoidable, we muff alfo admit that 
Metaphyfics are fubjeftively, and indeed necellarily, real; 
and may with reafon enquire into their objedivepojjibility. 
Without a folution of this Queftion, Reafon can never 
fatisfy itfelf. The ufe in experience, to which reafon li¬ 
mits the pure Underftanding, does not complete its own 
entire deftination. Every individual experience is only 
a part of the whole lphere of its territory ; but the abfo- 
lute whole of all poftible experience is itfelf not experience, 
and yet a neceiTary problem for Reafon ; for the mere re- 
prefentation of which, it Hands in need of quite different 
conceptions from thole of pure Underftanding, whofe ufe 
is immanent only ; i. e. confined to experience as far as it 
can be given ; while Conceptions of ReaJ’on, or Ideas, re¬ 
quire completenefs, i. e. colleftive unity of the whole of 
poflible experience ; and thus go beyond every given ex¬ 
perience, and become tranfeendent. 
In the fame manner as the Underftanding flood in need 
of the Categories for Experience, lb does RcaJ'on con¬ 
tain in itfelf the ground for Ideas, by which I underftand 
neceffary conceptions, whofe objeft, however, cannot be 
given in any experience. The latter are as completely 
g rounded in the nature of Reafon, as the former are in the 
nature of the Underfianding 5 and, if the Ideas of Reafon 
carry with them an appearance which may eafily millead, 
the iliufion is unavoidable, although we may prevent its- 
mi Heading us. 
Since all iHulion confifts in taking thefubjedive ground, 
of a judgment for an objective one, it follows that the felf- 
knowledge of pure Reafon, in its tranfeendent ufe, will be 
the only preventative againft the errors into which Reafon 
fails when it mifunderftands its own deftination, and re¬ 
fers in a tranfeendent manner to an obje£t in itfelf; that 
which belongs only to its own fubjeft, and refers only to 
the conduct of it in its immanent ufe. 
The dillinftion of Ideas, that is, of the pure concep¬ 
tions of Reafon, from the Categories or pure concep¬ 
tions of the Undeijianding, as Knowledge of a quite dif¬ 
ferent kind, origin, and ufe, is fo important a requifite 
for founding of a fcience that is to contain the fyftem of 
all knowledge a priori, that, without fuch a diftinftio-n. 
Metaphysics are abfolutely impoffible, or at leaft, no¬ 
thing better than a diforderly and fruitlefs attempt to 
conllruft a houfe of cards. 
If the Critic of Pure Reafon had done nothing elfe but 
exhibit this difference, it would thereby have contributed 
more to the elucidation of our Conceptions, and to the 
conducting of our inveftigations in the field of Meta¬ 
physics, than all the endeavours to fatisfy the Tranfeen¬ 
dent Problems of Pure Reafon, which philofophers have 
hitherto carried on,-without ever confidering that they 
were in a quite different field from that of the under¬ 
ftanding, and therefore treating the conceptions of un¬ 
derftanding and of reafon, as if they were of the fame 
kind. 
Ail pure knowledge of underftanding has this peculia¬ 
rity, that its conceptions are given in experience, and that 
its principles admit of being confirmed by experience ; 
whereas the tranfeendent or ideal hnowledge of Reafon, can 
neither be given in experience, nor can its pofitions ever 
be confirmed or refuted by experience ; fo that any errors 
that may creep into it, can only be deteded by pure Rea- 
fim itfelf; which however is extremely difficult, becaufe 
this very Reafon becomes naturally dialedical in the ufe of 
its Ideas : this unavoidable iliufion cannot be checked by 
any objedive or dogmatical inveftigation of the things, 
but merely by a Jubjcdive examination of Reafon itfelf as 
a lource of Ideas. 
It has always been my greateft objeft in the Critic of 
Pure Reafon, to afeertain how it was poftible, not only 
to diftinguifti carefully the different kinds of knowledge, 
but alio to derive from their common lource conceptions 
belonging individually to each of them, in order that I 
might not only be able by knowing their origin to deter¬ 
mine their ufe, but alfo obtain the hitherto-unexpefted, 
but invaluable, advantage of knowing d priori, and ac¬ 
cording to principles, the completenefs of the enumera 
tion, claftification, and fpecification, of thefe Conceptions. 
Without this, the Metaphysics are but a rhapfody of 
which we never know that we poffefs the whole. This 
advantage, it is true, is confined to pure Philofophy ; but 
it is this alfo which conftitutes its very efience. 
As I had found the origin of the Categories in the 
four logical functions of the judgments of underftanding, 
it was natural enough to look lor the origin of Ideas in 
the three funftions of a Rational Conclulion ; for, if we 
really poflefs fuch pure conceptions of Reafon, ( tranfcen¬ 
dental Ideas,) they c^inot well be met with, luppofing 
them not to be innate, any where elfe but in that aft of 
Reafon, which, when it refers to form only, conftitutes 
the logic of Rational Conclufions, but, when it is applied 
to judgments of underftanding, conftitutes the tranfcen¬ 
dental ideas of pure Reafon. 
The formal difference of the Conclufions of Reafon, 
renders the divifion of them into Categorical, Hypothetical, 
and Disjunctive, necefl’ary. The conceptions of Reafon, 
which are founded on them, contain therefore, firft, the 
Idea of a complete Jubjefl; fecondly, the Idea of a complete 
4 Jeries 
