M E T A P 
fpirit of liis common fenfe, but aifo known and compre¬ 
hended, all that has been here delivered with lo much 
preparation, or, if he prefer the phrafe, with all the 
pomp of pedantry; namely, that we-are not able, by the 
greateft efforts of reafon, to overftep the field of experi¬ 
ence.- He muff acknowledge, however, when he comes 
gradually to be queftioned concerning the principles ol his 
Reafoning, that there are many of them not derived from 
experience, but which are independent of it, and valid 
a priori. How then, and with what argument, will he 
keep in bounds the Dogmatical Philofopher who carries 
thefe conceptions and principles beyond all poffible ex¬ 
perience, on the very ground that they are known inde¬ 
pendently of it? And even our adept of common fenfe 
himfelf is not fo fure, notwithftanding all his pretended 
and cheaply-acquired wifdom, tha^he does not imper¬ 
ceptibly ftray beyond the bounds of experience into the 
field of chimeras. In faft, he is deeply enough engaged 
with them, though he contrives to give a fort of eft'eft to 
his groundlel's pretenfions by the popularity of his lan¬ 
guage, Hating his petitions merely as probable, as reaf'on- 
able conjectures, cr as conclufions of analogy. 
From the earlieft times of Philofophy the enquirers 
into pure reafon have imagined, befides the lenfible things, 
or Phenomena, which conliitute the fenfible world, intel¬ 
lectual beings all'o, or noumena, of which they conftituted 
an intellectual world; and, as they looked upon a pheno¬ 
menon as nothing more than an iliufion, which was in¬ 
deed excufable in an uncultivated age, they gave reality 
to intellectual beings alone. 
In faCt, when w'e confider the objefts of the fenfes as 
mere phenomena, we therein acknowledge that they have 
as a foundation a thing in itfelf, although we do not 
know it in itfelf, but merely its appearance; i. e. the 
manner in which our fenfes are afieCted by this totally- 
-anknown J'omcthing. Underftanding, therefore, in adopt¬ 
ing phenomena, grants the exiftence of things in tliem- 
felves ; and fo far we may fay, that the reprefentation of 
fiuch beings as conliitute the foundation -of the pheno¬ 
mena, that is, mere intellectual beings, is not only ad- 
miflible, but indeed unavoidable. 
Our critical deduction does not exclude fuch things, 
noumena, but merely limits the principles of bEfthetics, 
and prevents their being extended to the noumena, where¬ 
by every thing would be changed into mere iliufion, con¬ 
fining their validity to objeCts of a poffible experience. 
Confiequently intellectual beings are admitted, but with 
this reftriftion, which allows of no exception : that we 
know nothing at all of thefe pure intellectual beings, nor 
indeed ever can know. For the pure conceptions of the 
underftanding, Categories , and the pure intuitions, Time 
and Space, refer merely to objeCts of poffible experience, 
confequently to mere fenfible beings, beyond which they 
have not the leaft fignification. 
There is indeed fomething in our pure conceptions of 
underftanding which fieems to feduce us into a tranjeendent 
ule of them, for fuch I call that ufe which goes beyond 
all poffible experience. Not only our conceptions oi J'ub- 
Jiauce, of power, of aflion, of reality, &c. are entirely in¬ 
dependent of experience, and contain no charaCteriftic 
of Sense, and may feem therefore to refer, in faft. to the 
things in themlelves (noumena) ; they contain alfo what 
indeed confirms this fuppofrtion, a neceftity which is 
never equalled by experience. The conception of CavJ'e 
implies a rule, according to which one Jiate follows 
another necefjarih); but experience can only teach us 
that frequently, and if we make great allowance, one 
ftate of things is commonly followed by another: it 
gives us therefore neither ftrift univerlality nor ne- 
ceftity. 
Conceptions of the underftanding, then, feem to have 
much more meaning and matter than is to be found in 
their mere ufe in experience; and thus the Underftand¬ 
ing lecretly builds beyond the city of Experience more 
extenfive fuburbs, which it fills with pure intelleftual 
H Y S I C S. 223 
beings; never remarking that it has overftepped the right 
ufe of its otherwife-juft conceptions. 
Two important, nay indifpenfible, though extremely 
dry, inveftigations, were therefore neceffary, and which 
are explained in the Critic, page 137 and 235. In the 
firft it is iliown, that Sense does not give the pure con¬ 
ceptions of underftanding in the concrete, but only fur- 
nilhes the fcheme for the ufe of them ; and that corre- 
fponding objefts are only met with in experience, as 
produfts of the Understanding from the materials of 
Sense. In the.fecond inveftigation it is lhown, that, al¬ 
though our pure conceptions of underftanding are inde¬ 
pendent of experience, and though they feem to promile a 
greater extent of their ufe beyond its limits, yet out of 
the field of experience nothing at all can be thought by 
them, iince they can do nothing but determine the logi¬ 
cal form of a Judgment in refpeft to given intuitions; 
and, as out of the territory of Sense there are no intui¬ 
tions, it follows that the pure conceptions mult there be 
entirely without meaning.' 
The imagination perhaps may be pardoned for forae- 
times indulging itfelf in romantic fancies, and venturing- 
beyond the bounds of experience; for at leaft the faculty 
is enlivened and ftrengthened by fuch a free play, and 
it is always eafier to moderate its boldnefs than to give 
it energy. But for the underftanding, whole bufinefs is 
to think, to indulge in fancies is quite inadmiffible; for 
it is this faculty alone which mult reft rain the flights of 
imagination, and let the neceffary bounds to it. The 
underftanding, however, runs at firft into this error very 
innocently, and with modefty. It commences by clear¬ 
ing up its elementary knowledge, which it finds inherent 
in itfelf prior to experience, though its right application 
is ftriftly confined to experience. Gradually, however, 
it wanders out of this field; and what indeed is there to 
hinder it, lince it derives its principles purely from itfelf ? 
Firft, it invents new powers in nature, then beings out 
of nature, and fo forms an entire univerfe, for whole 
conftruftion it can never want materials, fince thefe are 
richly provided with a fruitful fancy; and, though its 
fiftions are not indeed confirmed by experience, yet they 
are never contradifted by it. This is the reafon why 
young philofophers are fo fond of the genuine dogmati¬ 
cal method, and often facriiice their time, and otherwife 
ufieful talents, to it. 
It is vain to attempt to moderate thefe fruitlefis {pecu¬ 
lations of pure reafon, by urging the difficulty of folving 
fuch deep queftions, or to complain of the limited nature 
of human reafon. For, until the impoffibility of folving 
thefe queftions is clearly proved, and the Jef-knowledge 
of reafon has become a genuine Icience, - in which its 
right ufe is diftinguifhed with geometrical certainty from 
its futile and ufelefs occupation, thefe vain endeavours 
will never be completely abolilhed. 
How is Nature itself possiele? 
This queftion, which is the- higheft point that tran¬ 
scendental philosophy can ever attain, properly con¬ 
tains two queftions. Firft, How is Nature materially 
confidered poffible"? that is, conlidered according to in¬ 
tuition, as the whole of phenomena. How are Time and 
Space, and all that fills them, i. e. the objefts of feeling, 
poffible ? The anfwer is, By means of th% Conftitution 
of our sensitive faculty, according to which it is 
affefted in a manner peculiar to itfelf by objefts in them¬ 
lelves unknown, and entirely different from the pheno¬ 
mena. This in the Critic of Pure Reafon is treated of 
under Tranjcendental JEjihetics. Secondly, How is Nature 
formally conlidered poffible? that is, confidered as the 
complex of Rules, under which all phenomena mult 
Hand, in order to be connefted in experience ? The an¬ 
fwer is, That it is only poffible by means of the conftitu¬ 
tion of our Understanding, according to which all the 
reprefentations of fenfe are neceffarily referred to a con- 
feioufnefs, according to rules, by means of which expe¬ 
rience 
