This work aims to develop the Kantian concept of self, or rather consciousness of self, in terms of its specific epistemological meaning. The author approaches this fundamental topic, which is undoubtedly at the basis of critical idealism, by comprehensively reconstructing the immanent lines of development of Kant's theory of subject on the basis of precise text analyses. He traces them from their origins in the "silent decade" of the 1770s via the discussion of paralogism to the experimental drafts of the late reflections.