Is moral judgment based on sentiment or on reason? I argue that this question poses a false dichotomy. Sentimentalists correctly point out that emotions play a crucial role in moral judgment – a point that is incontrovertible in the light of many recent experiments. This, however, is not the whole story. Relying on evidence from moral psychologists, I posit that emotions – in particular anticipatory guilt feelings – frequently trigger processes of reasoning (rationalizations). Those reasoning processes in turn affect people’s emotions – for instance, feelings of guilt might subside. This means that affect and cognition interact in the formation of moral judgment. I make this idea precise in terms of what I call ‘the Cognitive Dissonance Model of moral reasoning’. As the judgments to which moral reasoning gives rise can be justified, the view that I develop can be seen as a form of rationalism. As it also accords an ineliminable role to emotions, I dub the view ‘Sentimental Rationalism’. A central thesis of Sentimental Rationalism is that both cognition and affect can play a constructive as well as a destructive role in moral judgment.