ses: metaphysics in general, and metaphysics as science) possible? The
Transcendental _Aesthetic_ (the critique of sensibility or the faculty
of intuition) answers the first of these questions; the Transcendental
_Analytic_ (the critique of the understanding), the second; and the
Transcendental _Dialectic_ (the critique of "reason" in the narrower sense)
and the Transcendental _Doctrine of Method (Methodenlehre)_, the third. The
Analytic and the Dialectic are the two parts of the Transcendental "Logic"
(critique of the faculty of thought), which, together with the Aesthetic,
forms the Transcendental "Doctrine of Elements" _(Elementarlehre)_, in
contrast to the Doctrine of Method. The _Critique of Pure Reason_ follows
this scheme of subordinate division, while the _Prolegomena_ co-ordinates
all four parts in the manner first mentioned.

Let us anticipate the answers. Pure mathematics is possible, because there
are pure or _a priori intuitions_ (space and time), and pure natural
science or the metaphysics of phenomena, because there are _a priori
concepts_ (categories) _and principles_ of the pure understanding.
Metaphysics as a presumptive science of the suprasensible has been possible
in the form of unsuccessful attempts, because there are _Ideas_ or concepts
of reason which point beyond experience and look as though knowable objects
were given through them; but as real science it is not possible, because
the application of the categories is restricted to the limits of
experience, while the objects thought through the Ideas cannot be
sensuously given, and all assumed knowledge of them becomes involved in
irresolvable contradictions (antinomies). On the other hand, a science is
possible and necessary to teach the correct use of the categories, which
may be applied to phenomena alone, and of the Ideas, which may be applied
only to our knowledge of things (and our volition), and to determine the
origin and the limits of our knowledge--that is to say, a transcendental
philosophy. In regard to metaphysics (knowledge from pure reason), then,
this is the conclusion reached: Rejection of transcendent metaphysics (that
which goes beyond experience), recognition and development of immanent
metaphysics (that which remains within the limits of possible experience).
It is not possible as a metaphysic of things in themselves; it is possible
as a metaphysic of nature (of the totality of phenomena), and as a
metaphysic of knowledge (crit