The Dogma of the Unity of Practical Reasoning on Moral Grounds

This chapter offers a critical evaluation of a prevailing position in legal theory that analyses legal norms as a kind of reason for action. This view rests, among other things, on a unitary conception of practical reasoning that locates the fundamental source of the justificatory power of any kind of justifying reason in morality. It also presupposes a particular conception of morality itself. In the first part of the chapter, I apply Bernard Williams’s perspective to criticise the conception of morality adopted by this position, as well as its corresponding account of reasons and rational justification. On this basis, I challenge the equation between what is justified and what one morally ought to do. In the second part of the chapter, I return to the debate on the conditions under which law can justify decisions. In this context, I clarify in what sense the connection between law and morality may be relevant for the justification of actions, and in what sense it is completely irrelevant. In particular, with regard to cases of conflict between legal reasons, I emphasise that it is also possible to reject the widely accepted notion that one must always act for an undefeated reason. I argue that, according to an adequate account of reasons in cases of conflict, one may be justified in acting on reasons that are, strictly speaking, defeated. Drawing on Williams’s reflections on morality and reasons, I conclude that law can constitute a distinct set of reasons that are not necessarily subordinate to morality.