Abstract

In his long-awaited book On What Matters Parfit develops a normative theory that covers a whole range of normative concepts, from reasons and rationality to questions of moral progress and meaning of life. This paper focuses on Parfit*s view on reasons and rationality, and especially concentrates on three theses that are implicitly or explicitly endorsed by Parfit. The theses are: 1) the concept of a normative reason cannot be explicated in a non-circular way, 2) rationality of non-normative beliefs never influences the rationality of desires and actions, and 3) there are no desire-based reasons. The main aim of the paper is to critically evaluate the plausibility of the latter three theses.