This volume examines (1) the philosophical sources of the Kantian concepts "apperception" and "self-consciousness", (2) the historical development of the theories of apperception and deduction of categories within the pre-critical period, (3) the structure and content of A- as well as B-deduction of categories, and finally (4) the Kantian (and non-Kantian) meaning of "apperception" and "self-consciousness".