What You’re Rationally Required to Do and What You Ought to Do (Are the Same Thing!)

This chapter is about whether we ought to be rational—i.e., whether rationality is normative or deontically significant. Although this is a truism, skepticism about whether we ought to be rational is popular in the wake of very influential work by John Broome and Niko Kolodny. This chapter argues that Reasons Responsiveness vindicates the deontic significance of rationality. It is argued that it is independently plausible that what one deliberatively ought to do is determined by the reasons one possesses. The argument for this is anchored in the thought that there is a constitutive connection between deliberative obligations and being able to correctly respond to reasons. If this is right, then what one ought to do and what one is rationally required to do are the same thing. Thus, rationality has ultimate deontic significance.