Wolff, Robert Paul, Kant's Theory of Mental Activity, Cambridge, Mass: Harvard University Press, 1963.

From a review:

“Professor Wolff holds —rightly, I think—that there are 3 keys to the Kantian doctrine. The 1st is the epistemological turn; that is, the progressive substitution of epistemological for ontological or metaphysical considerations. “We may abstract from the  perceptual peculiarities of the individual, from the particular state of scientific advance of his age and even from the most pervasive social and cultural biases, but we can never abstract from the subject qua knowing the human being.” But if this statement, which in some interpretations is unobjectionable, is accepted, 2 questions immediately arise: how, if at all, can one distinguish between the permanent mental habits and assumptions of the subject “as such” on the one hand, and those which are characteristic of the subject qua member of a changing, mental, especially scientific, environment on the other? And did Kant  succeed in making this distinction? The answer to the 2nd question depends on the answer to the 1st, which cannot be avoided if not only the meaning but also the truth of Kantian philosophy is under investigation.

Review in: The Philosophical Review, Vol, 73, No. 4

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