even though experience shows the contrary of what on supposition of
freedom are conceived as its necessary consequences. On the other side
it is equally necessary that everything that takes place should be
fixedly determined according to laws of nature. This necessity of
nature is likewise not an empirical conception, just for this
reason, that it involves the motion of necessity and consequently of a
priori cognition. But this conception of a system of nature is
confirmed by experience; and it must even be inevitably presupposed if
experience itself is to be possible, that is, a connected knowledge of
the objects of sense resting on general laws. Therefore freedom is
only an idea of reason, and its objective reality in itself is
doubtful; while nature is a concept of the understanding which proves,
and must necessarily prove, its reality in examples of experience.

There arises from this a dialectic of reason, since the freedom
attributed to the will appears to contradict the necessity of
nature, and placed between these two ways reason for speculative
purposes finds the road of physical necessity much more beaten and
more appropriate than that of freedom; yet for practical purposes
the narrow footpath of freedom is the only one on which it is possible
to make use of reason in our conduct; hence it is just as impossible
for the subtlest philosophy as for the commonest reason of men to
argue away freedom. Philosophy must then assume that no real
contradiction will be found between freedom and physical necessity
of the same human actions, for it cannot give up the conception of
nature any more than that of freedom.

Nevertheless, even though we should never be able to comprehend
how freedom is possible, we must at least remove this apparent
contradiction in a convincing manner. For if the thought of freedom