Reason and Reasons

Abstract Grice begins this chapter by discussing to what extent the notion of variable rationality can be derived from that of flat rationality, and thus from the concept of a rational being alone. He then draws a distinction between ‘explanatory’ (motivating) and ‘justificatory’ (normative) reasons, as well as ‘personal’ reasons that combine the two by being reasons acted upon and regarded as justifying by the agent. Finally, he introduces a structural representation for practical and alethic justificatory reasons that shows that ‘common modals’ (ought, must, necessary, etc.) are used univocally on both sides of the practical/alethic divide. This representation consists of a single modal operator ‘Acc’ (‘it is acceptable that’), two mood‐operators ‘!’ (practical ) and ‘⊥’ (alethic), and a phrastic ‘r’ that these operators apply to.