There is an interpretative puzzle at the centre of Kant’s Groundwork for the Metaphysics of Morals. The text presents the single principle of morality (G, 4: 392), but instead of providing a definitive statement of the principle, we find a three-step sequence of formulas. The puzzle concerns the formula relation: given the contrast between the moral law’s individuality and the plurality of formulas, how do the formulas relate to each other and the moral law? This paper takes the first step towards a new account by focusing on G, 4: 436, a passage in which Kant makes claims about the matter and form of the moral law. By understanding the hylomorphism entailed by these claims, it is possible to achieve new perspectives on common questions about Kant’s ethics, in particular, the role of the formulas in deriving or explaining duties and how the formulas are used in the argument of Groundwork II and its transition from popular moral philosophy to metaphysics of morals.

On the currently dominant reading of the Groundwork, Kant’s derivation of ‘imperatives of duty’ exemplifies a decision procedure for the derivation of concrete duties in moral deliberation. However, Kant’s response to an often-misidentified criticism of the Groundwork by G. A. Tittel suggests that Kant was remarkably unconcerned with arguing for the practicality of the categorical imperative as a decision procedure. Instead, I argue that the main aim of Kant’s derivation of imperatives of duty was to show how his analysis of the form of moral judgement is indeed presupposed in the four types of moral imperative that philosophers of his time recognized.

Discussing the concept of duty in Groundwork 1, Kant refers to a ‘second proposition’ and a ‘third proposition’, the latter being a ‘Folgerung aus beiden vorigen’. However, Kant does not identify what the ‘first proposition’ is. In this paper, I will argue that the first proposition is this: An action from duty is an action from respect for the moral law. I defend this claim against a critique put forward by Allison according to which ‘respect’ is a concept that is not, and could not be, introduced in paragraphs 9–13 of Groundwork 1. Further, I will argue that the first proposition as I understand it can also be reconstructed as the conclusion (‘Folgerung’) of a deductive argument proper; however, I will also discuss the option that ‘Folgerung’ could be understood as a corollary rather than a conclusion. Finally, Allison's own interpretation will be criticized.