Abstract

In the First Section of the Groundwork of the Metaphysics of Morals, Kant argues that a good-willed person “under subjective limitations and hindrances” (G 397) is required “never to act except in such a way that [she] could also will that [her] maxim should become a universal law” (G 402).2 This requirement has come to be known as the Formula of Universal Law (FUL) version of the Categorical Imperative, an “ought” statement expressing a command of reason that “represent[s] an action as objectively necessary of itself, without reference to another end” (G 414). The question of how to understand and apply the FUL has received a great deal of attention in recent years. But Kant’s reasoning for the claim that a good-willed person (of a certain kind) acts in accordance with the FUL has not been investigated with the same degree of thoroughness. My purpose in this paper is to render the structure of Kant’s argument perspicuous, and thereby contribute to its proper evaluation by identifying its true strengths and weaknesses.3 Let us call Kant’s argument “K” and its conclusion “C”. The task at hand requires identification of K’s premises and of the reasoning by means of which C is derived. One of the advantages of clarifying K’s structure in this way is that doing so permits us to answer questions that continue to puzzle even the most sympathetic readers of the First Section. Some of these questions concern three “Propositions” to which Kant 1 draws our attention in the course of his presentation. The First Proposition (call it “P1”) is left unstated, but most commentators agree that it (or at least part of it) should be rendered as follows: (P1) A human action has moral worth only if it is done from duty.4 Kant states the other two propositions (call the Second “P2” and Third “P3”) explicitly: (P2) An action from duty has its moral worth not in the purpose to be attained by it but in the maxim in accordance with which it is decided upon. (G 399).