The Varieties of Moral Improvement,or why Metaethical Constructivism must Explain Moral Progress

Among the available metaethical views, it would seem that moral realism—in particular moral naturalism—must explain the possibility of moral progress. We see this in the oft-used argument from disagreement against various moral realist views. My suggestion in this paper is that, surprisingly, metaethical constructivism has at least as pressing a need to explain moral progress. I take moral progress to be, minimally, the opportunity to access and to act in light of moral facts of the matter, whether they are mind-independent or -dependent. For the metaethical constructivist, however, I add that moral progress ought also mean that agents come to be or could come to be motivated to act in light of the right kind of moral judgments. Together I take this to mean that, for all forms of constructivism, moral progress must be explained as a form of moral improvement, or agents aspiring to be better sorts of moral agents. In what moral improvement consists differs for various forms of constructivism. Here I distinguish between three different versions of metaethical constructivism: Humean constructivists as represented by Street (2008, 2010, 2012), Kantian constitutivist constructivists as represented by Korsgaard, and constructivists about practical reason as represented by Carla Bagnoli (2002, 2013). I conclude by showing that only constructivism as a view about practical reason can fully account for moral progress qua the opportunity for moral improvement.