science which has to do with objects--that, if once it is conducted
into the sure path of science, by means of this criticism, it can then
take in the whole sphere of its cognitions, and can thus complete
its work, and leave it for the use of posterity, as a capital which
can never receive fresh accessions. For metaphysics has to deal only
with principles and with the limitations of its own employment as
determined by these principles. To this perfection it is, therefore,
bound, as the fundamental science, to attain, and to it the maxim
may justly be applied:

Nil actum reputans, si quid superesset agendum.

But, it will be asked, what kind of a treasure is this that we
propose to bequeath to posterity? What is the real value of this
system of metaphysics, purified by criticism, and thereby reduced to
a permanent condition? A cursory view of the present work will lead
to the supposition that its use is merely negative, that it only serves
to warn us against venturing, with speculative reason, beyond the
limits of experience. This is, in fact, its primary use. But this,
at once, assumes a positive value, when we observe that the principles
with which speculative reason endeavours to transcend its limits
lead inevitably, not to the extension, but to the contraction of the
use of reason, inasmuch as they threaten to extend the limits of
sensibility, which is their proper sphere, over the entire realm of
thought and, thus, to supplant the pure (practical) use of reason.
So far, then, as this criticism is occupied in confining speculative
reason within its proper bounds, it is only negative; but, inasmuch
as it thereby, at the same time, removes an obstacle which impedes
and even threatens to destroy the use of practical reason, it possesses
a positive and very important value. In order to admit this, we have