Is Kant a Moral Realist?

In "The Sources of Normativity" Christine Korsgaard attempts to defend Kant's moral ontology as a kind of moral realism. She does so by way of drawing a distinction between substantial and procedural moral realism. After dismissing substantial realism as dogmatic and defending procedural moral realism, she goes on to claim that Kant's view is best described as procedural moral realism. It has been argued against Korsgaard that procedural moral realism is a misnomer and that it turns out to be an anti-realist position. I don't think that this criticism is correct and I will defend Korsgaard against the subjectivist objections that have been leveled against her. However, my main concern is to show why even Korsgaard's procedural moral realism is still not completely in line with Kant's own epistemological and ontological commitments. In contrast to Korsgaard, I argue that Kant's conception of reason as a capacity that is "by itself practical" commits him to a position which is best described by what I will call "moral idealism." Practical reason is not merely a faculty for cognizing some testing procedure that would reliably distinguish between good and bad maxims. In Kant, practical cognition consists in cognition of what I ought to do such that I do it, i.e. bring the object of my cognition into existence through a kind of self-affection.