The very same thing will also hold for the postulates empirical thinking in general, which together concern the synthesis of mere intuition (of the form of appearance), of perception (of its matter), and of experience (of the relation of these perceptions), namely that they are only regula tive principles, and that they differ from the mathematical principles, which are constitutive, not, to be sure, in their certainty, which is estab lished a priori in both cases, but yet in the manner of their evidence,.e., with regard to their intuitiveness (thus also their demonstration).