Moral disagreement and non-moral ignorance

The existence of deep and persistent moral disagreement poses a problem for a defender of moral knowledge. It seems particularly clear that a philosopher who thinks that we know a great many moral truths should explain how human populations have failed to converge on those truths. In this paper, I do two things. First, I show that the problem is more difficult than it is often taken to be, and second, I criticize a popular response, which involves claiming that many false moral beliefs are the product of nonmoral ignorance.