What can a moral realist say about why we should take morality seriously and about the relation between morality and rationality? I take off from Christine Korsgaard's criticism of moral realism on this score. The aim is to achieve an understanding of the relation between moral and rational properties and of the role of practical deliberation on a realist view. I argue that the justification for being concerned with rational and moral normative properties may not be an aspect of our minds to which we have access. I argue against a view that gives automatic pride of place to the rational properties of our mind by drawing attention to valuable non-rational modes of thought such as creative, imaginative and instinctive thought. Thus the value of taking account of rationality is contingent on its benefits. But this is not why we should be taking account of morality.