Fichte founded a revolutionary philosophical movement and invented an entirely new kind of philosophy; and he did so knowingly and intentionally. Yet, paradoxically, he did all this merely in the course of attempting to complete the philosophical project of Kant and protect the Critical philosophy against the possibility of skeptical objections. Kant had distinguished the activity of critique from that of science, and advertised the Critique of Pure Reason as a propaedeutic or methodological inquiry, examining our powers of cognition so as to clear the ground for philosophy as a systematic science and to indicate how such a science might be made actual (KrV A xxi/B xxxv–xxxvii). Fichte saw his task as that of bringing Kant's work to completion by turning the new Kantian philosophical standpoint into a science by constructing the system to which Kant's Critiques were merely preparatory.

In order to accomplish this task, Fichte thought he had to overcome several obstacles remaining in the standpoint of Kantian critique itself. Kant had seen that skepticism must be answered by starting from the condition for the possibility of cognition and providing a transcendental justification of knowledge by grounding it in those conditions. But he had undertaken this project using an account of cognition that was not sufficiently fundamental, because it already assumed some things that were likely objects of skeptical doubt. Or as Fichte puts it, Kant had incorporated into the standpoint of transcendental critique a good deal that belongs to “metaphysics,” which operates within the “ordinary point of view” and tries to explain it (SW 1:33).