Abstract

A major obstacle in the way of any rationalistic understanding of morality is that the moral ‘ought' obliges action: and on the (neo-)Humean view, action is thought to require affect. If, however, one could show that “ordinary” practical reasons are by themselves action-guiding, then moral reasons – a particular sort of practical reasons – also have no need of desire to “move” us to act. So how does the practical ‘ought' work? To answer that, we need to ask what exactly it is to be ‘guided' by reason in theoretical matters. And then we find that, in fact, theoretical reason is to be understood on the basis of practical reason, and not vice- versa. The argument proceeds by way of the internalism/externalism debate; practical and theoretical contradiction; and a critique of Humean assumptions about motivation. If it is broadly right, then the ground may have been cleared for an understanding of moral obligation as rational obligation, which is the larger thesis I have in view. S. Afr. J. Philos. Vol.24(2) 2005: 109-120