On Korsgaard’s argument for Kant’s moral law

ABSTRACT

Kant’s formula of universal law says that it is morally impermissible to act on maxims which lead to a contradiction, when universalized. Korsgaard famously argues that we should understand the contradiction involved in Kant’s formula of universal law test as practical contradiction. In her later works, Korsgaard provides an argument for the truth of Kant’s moral law from the principles that are, on her view, constitutive of human agency, including the principle of publicity, the principle of universality and the hypothetical imperative. In this paper I will, first, clarify Korsgaard’s argument, and, then, argue that her argument cannot vindicate Kant’s moral law. More specifically, I will argue that Korsgaard’s principles, contrary to what she aims, fail to occupy a middle ground between agent-neutral and agent-relative morality; for they rest upon an ambiguity in the notion of sharing the ends of other agents. As a result, Korsgaard’s constitutive principles are either implausible, or too weak to be able to ground our ordinary moral obligations.

KEYWORDS:

• Korsgaard
• Kant
• the moral law
• publicity of reasons
• agent-relative
• agent-neutral
• reasons
• constitutivism

Acknowledgements

A version of the paper was presented at Rutgers University. I am grateful to those who attended for providing helpful comments, especially Ruth Chang, Larry Temkin, Holly Smith, and Douglas Husak. I would like to thank Mahmoud Morvarid for helpful conversations about the paper. I am also thankful to the reviewers of Inquiry for their very constructive comments. I would also like to thank Iran National Science Foundation:INSF for supporting this project.

Disclosure statement

No potential conflict of interest was reported by the author.

Notes

1 On the narrow-scope reading of the hypothetical imperative, roughly speaking, the rationality of intending the means is determined by the rationality of the ends we happen to have. On the wide-scope reading, the hypothetical imperative does not make intending the means rational if our end is not rational. It just forbids one to intend the end without simultaneously intending the means. However, both wide-scope and narrow-scope readings imply that if our ends are rational, to intend the means would be rational too.

2 By ‘human beings’ I mean all creatures with Kantian humanity.

3 ‘The Categorical imperative simply tells us to choose a law. Its only constraint on our choice is that it have the form of a law. And nothing determines what that law must be. All that it has to be is a law’ (1996b, 81); see also (Korsgaard 2009, 80).

4 ‘The categorical imperative is the law of acting only on maxims that you can will to be universal laws. The moral law, as I characterized it there, is the law of acting only on maxims that all rational beings could act on together in a workable cooperative system’ (2009, 80). ‘In [Kant’s Formula of Universal Law], however, I do not distinguish the categorical imperative from the moral law, and my arguments [against the Hegelian objection that the Categorical Imperative is empty] there actually only show that the moral law has content’ (1996b, 82).

5 The argument for publicity of reason, according to Korsgaard, has the same form as the argument for the principle of universality. If my maxim is not universalizable, I would be a mere heap of impulses, and if my reasons are not public I would be a mere heap of private reasons. Integrity requires both universality and publicity.

6 In stage B, Korsgaards says: ‘if I am to think I have a reason to shoot you, I must be able to will that you should shoot me.’ This is the principle (K) which, as I explained, is entailed by (PP) and (PU).

7 We can express this argument in a formalized language. Let’s represent the proposition that it is rational for A to act on the maxim that ‘I will ϕ’ (here, ‘I will shoot the other person to get the object we are competing for’), as R(A, Aϕs), and the proposition that A can rationally will (or endorse) B’s ϕ’ing as W(A, Bϕs). We have:$\begin{array}{rl}& \left(PU\right)R(A,A\varphi s)\mathrm{o}\mathrm{n}\mathrm{l}\mathrm{y}\mathrm{i}\mathrm{f}\left(x\right)R(x,x\varphi s)\\ & \left(PP\right)\left(x\right)\left[R\right(x,x\varphi s\left)\mathrm{o}\mathrm{n}\mathrm{l}\mathrm{y}\mathrm{i}\mathrm{f}\right(y\left)W\right(y,x\varphi s\left)\right]\\ & \left(PC\right)IfR(A,A\varphi s)\mathrm{t}\mathrm{h}\mathrm{e}\mathrm{n}\sim W(A,B\varphi s)\end{array}$(PU) and (PP) entail that R(A, Aϕs) only if (x)(y) W(y, xϕs). Replacing y with A and x with B, we can infer that R(A, Aϕs) only if W(A, Bϕs). The consequents of this and (PC) are in contradiction and therefore we can infer that their antecedent is false, i.e. ∼R(A, Aϕs).

8 Thanks to a reviewer of Inquiry for pressing me to clarify the issue.