224 * METAPHYSICS. 
rience is alone poflible. This the Critic of Pure Reafon 
treats of under Tranjcendental Logic. 
But how this peculiar conftitution of our fenfitive fa¬ 
culty, or of our Under/landing, and the necefl'ary con¬ 
sciousness which forms the foundation of it, and of all 
thinking, is poflible, cannot be further explained, becaufe 
we mull always refer to confcioufnefs in all our enquiries. 
There are many laws of nature which can only be 
known by means of experience; but the order in the 
connexion of the phenomena, i. e. of nature in general, 
we cannot learn by any experience, fince experience itfelf 
frauds in need of general laws which form the foundation 
of its poflibility a priori. 
The poflibility of experience, therefore, is at the feme 
time the univerfal law of nature; and the principles of 
the former are the laws of the latter. For we know na¬ 
ture no otherwife but as the whole of phenomena, i. e. 
of the reprefentations in us; and cannot therefore de¬ 
rive the law of their connexion from any fource but 
from the principles of connexion in us, i. e. from the 
conditions of a necefl'ary union in a confciovfnefs which 
conllitutes the poflibility of Nature. 
Even the chief polition which has been treated through¬ 
out this -whole fedtion, that univerfal laws of nature may 
be known a priori, leads already of itfelf to the pofltion, 
that the faprcme legifiation of Nature muft He in vs, i. e. in 
our Underftanding; and that we mull not feek the uni¬ 
verfal laws of Nature from nature itfelf by means of ex¬ 
perience, but converfely, feek the univerfal legitimacy of 
nature in the mere conditions of the poflibility of expe¬ 
rience, lying in our fenfitive faculty and Underfunding ; 
for how would it be otherwife poflible to know the laws 
of Nature a priori! Such a necefl'ary coincidence of the 
principles of poflible experience with the laws of the pol- 
fibility of nature, can only arife from two caufes : either 
the laws of nature are derived from nature itfelf by 
means of experience, or nature is itfelf derived frefrn the 
laws of the poflibility of experience; and thus the laws 
of nature are nothing more than mere laws of expe¬ 
rience. The firlt contradicts itfelf; for the univerfal laws 
of nature can and mall be known a priori, (i. e. inde¬ 
pendently of all experience,) and muft be made a foun¬ 
dation to all empirical ufe of the Underftanding; confe- 
quently only the lecond remains.. 
But we muft diftinguifli the empirical laws of nature, 
•which always prel'uppofe particular apprehenfions, from 
the pure and univerfal laws of nature, which merely con¬ 
tain the conditions of a necefl'ary union in experience; 
and with refpedt to which, nature and poflible experience 
are precifelij the fame. It follows then, that the Under¬ 
ftanding docs not derive its laics a priori from Nature, bat 
preferibes them to Nature. 
Let us elucidate this apparently-bold pofltion by an 
example, to fliow that the laws, which we difeover in ob¬ 
jects of lenfible intuition, particularly if they are necef- 
fary laws, are contidered by us as being placed by the 
■ underftanding in thefe objeCts, though they differ in no 
other refpeft from fuch laws of nature as we aferibe to 
experience. 
If we coniider the properties of the circle, whereby this 
.figure unites, in a univerfal rule, fo many arbitrary deter¬ 
minations of fpace in it, we cannot forbear to attribute 
to this geometrical thing a certain nature. Thus two 
.lines which cut each other within a circle, in whatever 
accidental manner they may be drawn, divide themfelves 
always fo regularly, that the redtangle formed of the parts 
of each line is equal to that of the other. Now I afle. 
Does this law lie in the circle, or in the UNDERSTANDiNG ? 
i. e. Does this figure, independently of the Underftanding, 
contain the ground of this law in itfelf; or does the un¬ 
derftanding, bp confiructing the figure itfelf according to 
■ its own conceptions, namely, the equality of the radii, 
; lay at the fame time into this figure the law of the chords 
mterfeCting each other in geometrical proportion ? We 
.;uay foon perceive, if we follow the demonftrations of this 
law, that it can only be derived from the condition which 
the underftanding laid as a foundation to the conftruc- 
tion of this figure; namely, from the equality of the radii. 
Now, if we extend this example in order to purfue ftill 
further the unity of the various properties of geometri¬ 
cal figures' under common law r s, and if we confider the 
circle as a conic fedtion w’hich therefore Hands with other 
conic fedtions under the very fame fundamental condi¬ 
tions of their conftrudtion, we then find that all chords 
which interfedt each other within thofe fedtions, namely, 
within the Eilipfis, the Parabola, and the Hyperbola, al¬ 
ways make the redtangles which are compofed of their 
parts, not indeed equai, but in proportion to each other. 
If we proceed farther to the fundamental doftrines of 
phyfical aftronomy, we dilcover a phyfical law of mutual 
attraction fpread over material nature ; namely, that the 
attraction inverfely decreafes with the fquare of the dif- 
tances from the attracting point, in the fame manner as 
the globular furfaces into which this power diftufes itfelf 
increafe. This feems neceffarily to lie in the nature of 
the things, and is therefore ufually treated as knowable 
a priori. However fimple the fources of this law may be, 
fince they reft merely upon the relation of globular fur- 
faces of different diameters, yet its conl’equence is fo ex¬ 
cellent with refpefl to their numerous modes of agree¬ 
ment, and their regularity, that not only all poflible or¬ 
bits of the heavenly bodies occur in conic fedtions, but 
there arifes fuch a relation of them to each other, that 
no other law of attraction but that of the inverfe propor¬ 
tion of the fquares of the diftances can be invented as fit 
for a fyltem of the univerfe. 
Here then we fee nature refting upon laws which the 
underftanding knows a priori, and indeed chiefly upon 
univerfal principles of determination of Space. Now I 
afk, Do thefe laws of Nature lie m Space, and does the Un¬ 
derstanding learn them by merely endeavouring to in- 
veftigate,the profound meaning which lies hidden there; 
or do they lie in the Understanding, and in the man¬ 
ner in which it determines Space according to the con¬ 
ditions of that fynthetical unity in which all its concep¬ 
tions concur ? Space is fomething fo uniform, and fo un¬ 
determined with refpedt to all particular properties, that 
w-e cannot look there for the treafure of the laws of Na¬ 
ture. On the other hand, the Understanding is that 
which gives to Space the circular form, the figures of 
the Cone and of the Sphere, fince it contains the ground 
of the unity of their conftrudtion. The mere univerfal 
form of intuition, called Space, is indeed the fubftratum 
of all intuitions, and applicable to particular objedts. 
Space, indeed, is the condition of the poflibility and va¬ 
riety of intuitions ; but the unitij of objects is altogether 
determined by the underftanding according to conditions 
which lie in its own nature ; and thus does the under¬ 
ftanding originate the univerfal laws of Nature, by com- 
prifing all phenomena under laws of its own ; thus gene¬ 
rating experience as to its form a priori, and fubjedting 
all objects which can be known only by experience to its 
own laws. For we have nothing to do with the nature 
of the things in themselves, which is equally inder 
pendent of the conditions of our Senftive Faculty and 
of our Underftanding ; our buiinefs is to treat of nature 
as an objedt of poflible experience ; and the underftand- 
ing, by rendering experience poflible, either excludes the 
fenfible world from experience, or constitutes its nature. 
Nothing can be more delirable to a philolopher than to 
derive from a principle a priori all the variety of concep¬ 
tions or principles which before had prefented themfelves 
to him disjointedly in his ufe of them in the concrete, 
and thus to unite every thing into one branch of Know¬ 
ledge. Formerly he believed that all that remained after 
a certain abllradlion, and which Teemed to conftitute a 
particular kind of knowledge, was completely collected ; 
but it ftill remained only an aggregate; now he knows that 
only fo much, and neither more nor lefs, can conftitute 
that particular kind of knowledge ; and he lees the ne- 
i ceflity 
