This chapter presents Kant's account of the relation between moral worth and motivation by respect for duty alone as well as his conceptions of virtue and merit as aspects of his underlying theory of free human agency. In the first section, I try to undercut recent debates about whether Kant's account of moral worth as motivation by respect for duty alone allows for the presence of “cooperating” inclinations by arguing that on Kant's account of free human agency there is no room for any conception of merely cooperating inclinations; instead, inclinations can only be granted motivational force by a person's freely chosen fundamental maxim and are, to some extent, even to be seen as products of that choice. In the second section, I argue that Kant's conception of virtue and his ultimate catalog of duties of virtue in the Metaphysics of Morals can also be explained only by reference to his conception of free human agency: what all forms of virtue and duties of virtue share is that they are all forms of conduct to which we can be constrained only by our own free choice of fundamental moral maxim. In the final section, I show how Kant's conception of merit fits into his image of human conduct as ruled by such a freely chosen fundamental moral maxim.