10/03/2025: Pauline Kleingeld on Kant and the Methods of Moral Philosophy

ABOUT

Pauline Kleingeld is Professor of Philosophy at the University of Groningen. Earlier she taught at Leiden University and at Washington University in St. Louis. She is the author of Kant and Cosmopolitanism (CUP 2012), Fortschritt und Vernunft: Zur Geschichtsphilosophie Kants (Königshausen und Neumann 1995) and numerous articles. Her academic interests are in ethics and political philosophy, with a special focus on Kant and Kantian theory.

ABSTRACT

In the first section of his Groundwork for the Metaphysics of Morals (G1), Immanuel Kant claims to identify the supreme principle of morality. After famous discussions of the idea of a ‘good will’, ‘acting from duty’ and ‘respect’, he concludes that the highest moral principle is the following: ‘I ought never to proceed except in such a way that I could also will that my maxim should become a universal law’ (G 4:402). He claims that this principle implicitly governs ordinary moral practices and convictions. It is the ‘supreme’ moral principle in that it is a meta-principle by means of which substantive Kantian moral principles — such as ‘help others in need’ or ‘never lie’ — can be derived. Because Kant’s argument draws on moral convictions that are still widely shared, and because his conclusion articulates a paradigmatic position in moral theory, G1 has become one of the most renowned texts in the history of philosophy.

The structure of Kant’s argument towards the identification of the supreme principle, however, has long been the subject of debate. Three serious difficulties stand out in the literature, and they all concern the most important steps of his argument:

(1) Kant presents his argument as consisting of three propositions and a conclusion, but he labels only the second and third propositions as such. He does not make explicit what he takes the first proposition to be. In recent decades at least a dozen candidates have been put forward in the literature (see Steigleder 2022).

(2) Kant claims that the third proposition follows from the first and the second, but it is widely regarded unclear how it is supposed to follow.

(3) Kant’s final step to the formulation of the supreme principle is often said to be a jump over a gap, rather than a careful step that follows from the preceding argument.

As a result, Kant’s reasoning towards the supreme moral principle seems more like a series of assertions and fragmentary arguments rather than a single argumentative chain.

In this paper, I argue that Kant’s views on philosophical method shed new light on the structure and direction of his argument in G1. It has gone unnoticed that this argument consists of a chain of regressive inferences. I first explain the current positions in the literature regarding Kant’s method in G1 (§2). I then turn to Kant’s views on method (§3). Using his description of the so-called ‘analytic method’, I reconstruct the argument of G1 as a regressive chain. I argue that this reconstruction suggests solutions to the three main difficulties diagnosed in the literature, although several unclarities remain (§4).