The Metaphysics of Morals by Immanuel Kant Chapter 3 Page 34

(in other words as belonging to the world of understanding).

Hence it comes to pass that man claims the possession of a will which takes no account of anything that comes under the head of desires and inclinations and, on the contrary, conceives actions as possible to him, nay, even as necessary which can only be done by disregarding all desires and sensible inclinations.

The causality of such actions lies in him as an intelligence and in the laws of effects and actions [which depend] on the principles of an intelligible world, of which indeed he knows nothing more than that in it pure reason alone independent of sensibility gives the law; moreover since it is only in that world, as an intelligence, that he is his proper self (being as man only the appearance of himself),