valid in the sphere of experience, on which account Kant has shown that it only serves to communicate the connection of experience, and not to transcend it; that thus it admits only of physical application, not of metaphysical. Certainly only its a priori origin can give apodictic certainty to any knowledge; but this limits it to the mere form of experience in general, for it shows that it is conditioned by the subjective nature of the intellect. Such knowledge, then, far from taking us beyond experience, gives only one part of experience itself, the formal part, which belongs to it throughout, and therefore is universal, consequently mere form without content. Since now metaphysics can least of all be confined to this, it must have also empirical sources of knowledge; therefore that preconceived idea of a metaphysic to be found purely a priori is necessarily vain. It is really a petitio principii of Kant's, which he expresses most distinctly in § 1 of the Prolegomena, that metaphysics must not draw its fundamental conceptions and principles from experience. In this it is assumed beforehand that only what we knew before all experience can extend beyond all possible experience. Supported by this, Kant then comes and shows that all such knowledge is nothing more than the form of the intellect for the purpose of experience, and consequently can never lead beyond experience, from which he then rightly deduces the impossibility of all metaphysics. But does it not rather seem utterly perverse that in order to discover the secret of experience, i.e., of the world which alone lies before us, we should look quite away from it, ignore its content, and take and use for its material only the empty forms of which we are conscious a priori? Is it not rather in keeping with the matter that the science of experience in general, and as such, should also be drawn from experience? Its problem itself is given it empirically; why should not the solution of it call in the assistance of experience? Is it not senseless that he who speaks of the nature of things should not look at things themselves, but should
