If we act out of some motive other than duty, such as self-interest, for example, our action lacks moral worth. This is true, Kant maintains, not only for self-interest but for any and all attempts to satisfy our wants, desires, preferences, and appetites. Kant contrasts motives such as these—he calls them “motives of inclination”—with the motive of duty. And he insists that only actions done out of the motive of duty have moral worth.
