Moral confirmation vs. moral explanation: A tale of two challenges

In the first chapter of The Nature of Morality (1977), Gilbert Harman sets out what he takes to be the “basic issue” confronting moral philosophy: whether moral principles can be “tested and confirmed in the way that scientific principles can . . . out in the world” (3-4). Harman argues that they can't be. In this paper I argue that if we reject the Harmanian view that confirmation is the converse of explanation, then we can agree with the naturalist realist on the basic epistemological issue of whether moral principles can be tested and confirmed in the way that scientific principles can. But I argue that there nevertheless is an important metaphysical way in which moral explanations differ from certain kinds of non-moral explanations. An upshot is that even realists who think that moral facts are necessary, causally inefficacious, and knowable a priori can agree that moral claims are subject to empirical confirmation in the way that scientific claims are.