Rationality as Reasons-Responsiveness

John Broome argues that rationality cannot consist in reasons-responsiveness since rationality supervenes on the mind, while reasons-responsiveness does not supervene on the mind. I here defend this conception of rationality by way of defending the assumption that reasons-responsiveness supervenes on the mind. Given the many advantages of an analysis of rationality in terms of reasons-responsiveness, and in light of independent considerations in favour of the view that reasons-responsiveness supervenes on the mind, we should take seriously the backup view, a hypothesis that explains why reasons-responsiveness supervenes on the mind even though paradigmatic reasons are external facts. I argue that Broome’s objections to the backup view, as well as his more general objection to the thesis that reasons-responsiveness supervenes on the mind, do not succeed.