These are the unfathomable difficulties that attach to knowledge: as regards act character, as regards meaning, as regards objectivity. And, roughly speaking, they are the problems peculiar to the thorny field of critique of knowledge in the concise sense. Whether they are separated off from formal logic, real logic, and noetic logic, which according to the foregoing represented the idea of a universal, pure logic for us, or combined with them into the unity of a single discipline not in itself a matter of great significance. One thing, though, is clear: only the critique of knowledge completes the circle of the disciplines essentially belonging to the idea of a theory of science. One can, therefore, justifiably understand the concept of logic so broadly that it embraces the critique of knowledge, that discipline ultimately elucidating the essence of theoretical reason, while, on the other hand, even the narrower concepts of logic that we separated off are also well-justified: formal logic, which is at the same time formal ontology, real ontology, noetics as logical theory of norms, and finally critique of knowledge, theory of knowledge or theory of reason. Even the theory of the art of knowledge and science, owing to its practico-technical aims, naturally relates to all these disciplines, provided it but sets its goal high enough, namely so high that it not merely guides us in delimiting and successfully cultivating sciences in the usual sense, but would assist us in the ultimate completion of scientific knowledge, therefore, as regards philosophy, in tending towards metaphysically conclusive knowledge.