ABSTRACT
There are several important arguments in metaethics that rely on explanatory considerations. Gilbert Harman has presented a challenge to the existence of moral facts that depends on the claim that the best explanation of our moral beliefs does not involve moral facts. The Reliability Challenge against moral realism depends on the claim that moral realism is incompatible with there being a satisfying explanation of our reliability about moral truths. This chapter examines these and related arguments and discusses four kinds of arguments- Harman's Challenge, evolutionary debunking arguments, irrelevant influence arguments, and the Reliability Challenge- understood as arguments against moral realism. To be fair, evolution may have a role to play if the Reliability Challenge is targeted against moral naturalism. According to moral naturalism, moral facts are natural facts. So they can play a role in causing natural phenomena.
