Kant's philosophy is usually treated according to 'internalist' textual methodology rather than contextually according to 'externalist' methodology. This book presents transcendental idealism, the metaphysics of morals, and other Kantian innovations in philosophy as a reaction to 18th century developments in the life and human sciences. It interprets Kant's metaphysics as motivated by, on one hand, anxiety over the moral dangers he perceived in the empiricism of Buffon, Hume, Smith, and certain German materialists; and, on the other, his theological scepticism.