Kant, who set himself the task of reconciling empiricism with rationalism, retained a certain dualism in his thought, that was fully overcome only by the philosophy of identity. The whole period between Kant and Fichte, the first representative of the post-Kantian speculative metaphysics, which culminated in the philosophy of identity, was dominated by the struggle against this dualism and by the attempt to replace it with a monism. The given object (thing-in-itself) and pure thought (a priori thought), matter and form, receptivity and spontaneity, a posteriori and a priori, the empirical and the intelligible, nature and man, causality and freedom — these are the characteristic features of Kantian dualism. It is true that Kant emphasized the priority of the second element in his dichotomy, i.e., form over matter, pure transcendental subjectivity over thing-in-itself, a priori over a posteriori, and so forth. Nevertheless, the first element — matter, thing-in-itself, and a posteriori — was not, so it seemed to the first interpreters of Kant, entirely discarded by the master but retained a definite and legitimate place in his system.