the fixed and necessary relation of perceptions. But in this sense experience is an idea (in Kant's meaning of the term) or an ideal. We can approach this ideal to infinity, but it was a piece of dogmatism when Kant here failed to distinguish between the ideal and reality. Kant had not, as he believed, solved the problem propounded by Hume; for the thing concerning which Hume was skeptical was just the matter as to whether any experience in the strict sense of the term really exists.—This dogmatic tendency is peculiarly prominent in Kant's special works, especially in his Metaphysische Anfangsgrunden der Naturwissen-schaft (1786).—Kant's chief merit consists in referring all knowledge to synthesis and continuity. These fundamental principles enable us to anticipate experience. But all anticipations are only hypotheses.
3. As we have observed, the demonstration of the real validity of abstract knowledge (of pure reason) is closely related to the limitation of this validity. Kant states this as follows: We know only experiences, but not things-in-themselves. Whenever he expresses himself concisely, he calls the concept of the thing-in-itself an ultimate concept or a negative concept. In this way he gives expression to the permanently irrational element of knowledge. Speaking exactly, the concept of the thing-in-itself indicates that we cannot deduce the matter of our knowledge from its form. For Kant however the concept of the thing-in-itself imperceptibly assumes a positive character. The thing-in-itself is regarded as the cause of phenomena (especially in reference to the matter, but likewise also in reference to the form). Here (as F. H. Jacobi was the first to show) Kant falls into a peculiar contradiction; he has limited the real validity of the concept of causality to the realm of experience (in which the thing-in-itself can never be pres-
