In his book Being Realistic about Reasons, Tim Scanlon defends normative cognitivism – the view that normative attitudes are beliefs – against the objection that it is unable to explain how normative attitudes motivate agents to act. He provides a rational explanation of why agents act in accordance with normative attitudes. I suggest that his explanation relies on a dispositional structure and I argue that this dispositional structure can be detached from the rational theory it is combined with in the rational explanation. Thereby, the cognitivist’s answer to the motivational objection can be formulated as a dispositinal explanation that is less controversial than the rational explanation and steers clear of disputes between rationalist internalists and externalists. Finally, I point out that there seems to be no rational explanation for actions performed for optional reasons, and that only dispositional explanations seem to accommodate these actions. This is a further advantage of giving dispositional explanations of acting on a normative judgement.

       My aim is to strengthen the case for normative cognitivism by making it acceptable even to the instrumentalist, and by accommodating motivation by optional reasons. We may account for the fact that people are motivated by normative attitudes – in ways which, according to Tim’s (and my) views about rationality, are rationally required or at least rationally permitted – by giving an explanation that is uncommitted to this view of rationality.