This paper addresses the issue of making sense of Kant’s notion of moral worth. Kant’s identification in GMM1 I of the good will as the unconditional good leads to understanding the moral worth of human agency in ways which, some critics claim, is at odds with our moral intuitions. By first focusing upon how Kant singles out action out of duty as characteristic of the good will, we shall show that a covert assumption about our nature potentially weakens the force (...) of Kant’s argument. This paper claims that this assumption is not needed, and proposes an interpretation of Kant’s notion of moral worth that dispenses with it. In so doing, the interpretative strategy draws upon Kant’s solution to the Third Antinomy, and therefore on Transcendental Idealism. An analysis of the moral worth of the action of a benevolent agent who heeds the requirements of duty will show how inclinations contribute to morally worthy action, while the action’s moral worth lies in its being motivated by duty. A further analysis of the issue of moral worth in the light of recent scholarship introduces a distinction between the moral worth of the action and of the agent. This provides the material to address an important standard criticism of Kantian ethics. The paper concludes by suggesting that the proposed interpretation is required to make proper sense of Kant’s indirect duty to develop compassionate inclinations. (shrink)