a priori cognition or metaphysic of objects, in so far as they are given a posteriori? and how is it possible to cognize the nature of things according to a priori principles, and to attain to a rational physiology? The answer is this. We take from experience nothing more than is requisite to present us with an object (in general) of the external or of the internal sense; in the former case, by the mere conception of matter (impenetrable and inanimate extension), in the latter, by the conception of a thinking being—given in the internal empirical representation, I think. As to the rest, we must not employ in our metaphysic of these objects any empirical principles (which add to the content of our conceptions by means of experience), for the purpose of forming by their help any judgements respecting these objects.
Secondly, what place shall we assign to empirical psychology, which has always been considered a part of Metaphysics, and from which in our time such important philosophical results have been expected, after the hope of constructing an a priori system of knowledge had been abandoned? I answer: It must be placed by the side of empirical physics or physics proper; that is, must be regarded as forming a part of applied philosophy, the a priori principles of which are contained in pure philosophy, which is therefore connected, although it must not be confounded, with psychology. Empirical psychology must therefore be banished from the sphere of metaphysics, and is indeed excluded by the very idea of that science. In conformity, however, with scholastic usage, we must permit it to occupy a place in metaphysics—but only as an appendix to it. We adopt this course from motives of economy; as psychology is not as yet full enough to occupy our attention as an independent study, while it is, at the same time, of too great importance to be entirely excluded or placed where it has still less affinity than it has with the subject of metaphysics. It is a stranger who has been long a guest; and we make it welcome to stay, until it can take up a more suitable abode in a complete system of Anthropology—the pendant to empirical physics.
The above is the general idea of metaphysics, which, as more was expected from it than could be looked for with justice, and as these pleasant expectations were unfortunately never realized, fell into general disrepute. Our Critique must have fully convinced the reader that, although metaphysics cannot form the foundation of religion, it must always be one of its most