ABSTRACT
The word ‘reason’ is very ambiguous, with the result that the term ‘practical reason’ may refer to two quite different topics. It may refer either to practical normativity or to practical rationality. The first is a matter of what one ought to do or has reason to do; the second is a matter of good practical reasoning and mental coherence in practical matters. Many philosophers fail to separate normativity from rationality as sharply as they should. Partly this is because they are confused by the ambiguity of ‘reason’ and partly because there are some substantive arguments that purport to show that there is no real distinction. This chapter enforces the distinction. It starts by separating the different meanings of ‘reason’ and then responds to the substantive arguments. The response turns on the conceptual feature of rationality that it is a property of the mind and supervenes on other properties of the mind. On the other hand, normativity does not supervene on the mind. The chapter concludes by discussing a Kantian approach to identifying normativity with rationality.
