Aims of the Discussion

The success of Kant's derivation of the Formula of Universal Law (as well as the Formula of Humanity) depends on his ability to eliminate rival candidates for the supreme principle of morality. To eliminate them Kant appeals to criteria for the supreme principle of morality. He argues that unlike his candidates, the rivals fail to remain as viable candidates for fulfilling the full set of criteria. As Chapter 7 illustrates in detail, the derivation relies on a criterion (or part of one) that has been a main topic for the past two chapters. This principle, the criterion goes, must be such that all and only actions conforming to it because it is morally required – that is, all and only actions done from duty – have moral worth. We now understand what this means and how Kant argues for it. This chapter explores the criterion's plausibility. It addresses objections to the view that an action has moral worth if and only if it is done from duty. The bulk of the chapter focuses on the claim that all actions done from duty have moral worth (sections 6.2–9). The penultimate section (6.10) takes up the claim that only actions from duty have such worth. The chapter focuses more on the former than the latter claim for a couple of reasons.