 However “Kantian” in spirit Fichte’s enterprise might have been, he was at the same time all too keenly aware of what he considered to be certain glaring weaknesses and inadequacies in Kant’s own execution of this project. Taking to heart the criticisms of such contemporaries as F. H. Jacobi, Salomon Maimon, and G. E. Schulze, Fichte propounded a radically revised version of the Critical philosophy. First of all, he argued that the very concept of a “thing in itself,” understood as a mind-independent, external “cause” of sensations, is indefensible on Critical grounds. In addition, he maintained that Kant’s denial of the possibility of “intellectual intuition,” though certainly justified as a denial of the possibility of any non-sensory awareness of external objects, is nevertheless difficult to reconcile with certain other Kantian doctrines regarding the I’s immediate presence to itself both as a (theoretically) cognizing subject (the doctrine of the transcendental apperception) and as a (practically) striving moral agent (the doctrine of the categorical imperative).