When an act is right or wrong, there may be an explanation why. Different moral theories recognize different moral facts and offer different explanations of them, but they offer no account of moral explanation itself. What, then, is its nature? This thesis seeks a systematic account of moral explanation within a framework of moral realism. In Chapter 1, I develop a pluralist theory of explanation. I argue that there is a prima facie distinctive normative mode of explanation that is essential to moral theory. In Chapter 2, I characterize normative explanation through its formal properties. I then draw on John Mackie’s claim that moral explanations are queer to develop a powerful form of moral scepticism. In Chapters 3–4, I reject attempts to...