Moral Skepticism and Moral Knowledge

Sarah McGrath
College of the Holy Cross

We have moral knowledge. For example, we know that slavery is wrong, that Bert should not have gratuitously stepped on Alice’s toe, and that wearing mismatched socks is permissible. Or so it appears. But the claim that we have moral knowledge is often found problematic. According to J. L. Mackie, if we had moral knowledge, “it would have to be by some special faculty of moral perception or intuition, utterly different from our ordinary ways of knowing everything else” (1977, p. 38). Mackie, of course, concludes from this that we do not have moral knowledge, because we have no such special faculty. Following Mackie, I distinguish two questions. First, assuming that we have moral knowledge, how do we have it? Second, do we in fact have any moral knowledge? I argue that Harman’s argument for moral skepticism does not succeed. While it might be true that if the answer to the first question were “by inference to the best explanation,” then the answer to the second question would be “no”, it is implausible that if we have moral knowledge, we get it from inference to the best explanation. Instead, I suggest, we at least sometimes get it by perception.