But what obscured the fundamental idea of metaphysics from yet another side was that, as a priori cognition, it shows a certain homogeneity with mathematics, to which, as far as a priori origin is concerned, it is no doubt related; but the comparison between the kind of cognition from concepts in the former with the manner of judging a priori through the mere construction of concepts in the latter requires a difference between philosophical and mathematical cognition thus a decided heterogeneity is revealed, which was always felt, as it were, but was never able to be brought to distinct criteria.