Joshua Gert

One strategy for providing an analysis of practical rationality is to start with the notion of a practical reason as primitive. Then it will be quite tempting to think that the rationality of an action can be defined rather simply in terms of ‘the balance of reasons’. But just as, for many philosophical purposes, it is extremely useful to identify the meaning of a word in terms of the systematic contribution the word makes to the meanings of whole sentences, this paper argues that it is extremely useful to explain the nature of practical reasons in terms of the systematic contributions that such reasons make to the wholesale rational statuses of actions. This strategy gives us a clear view of two logically distinct normative roles for practical reasons – justifying and requiring – that are often conflated, and it allows us to give clear definitions of what ‘the strength of a reason’ means within each of these roles. The final section of the paper explores some implications of the resulting view for the internalism/externalism debate about practical reasons, and for the practical significance of moral theory.

The question “Why be moral?” is open to at least three extremely different interpretations. One way to distinguish these interpretations is by picturing the question as being asked by, respectively, Allan, who is going to act immorally unless he can be convinced to act otherwise, Beth, who is perfectly happy to do what is morally required on a certain occasion but who wants to know what is it about the act that makes it morally required, and Charles, who is trying to understand why rational people act morally. An answer to the question as understood by Allan is, for some, the holy grail of moral philosophy, and it is also perhaps the default understanding of the question. The question as asked by Beth is what David Copp, in his contribution to this volume, calls the “why-think-morality-requires-this” question. The question as asked by Charles can be called the “what-rationally-justifies-moral-behaviour” question. Charles’ question, importantly, is about rational permissibility, and it is most pointed when moral behaviour requires sacrifice.