To the best of my knowledge, this is the best single volume on the realism/anti-realism dispute in contemporary meta-ethics. Basically, what is at issue between realists and anti-realists is the objectivity of ethics. According to Sayre-McCord, the central issue is the existence of moral facts. Realists claim that such facts exist; anti-realists deny their existence. There is more to the debate than this, however. The following is a list of claims that most realists will make about morality: (i) there are moral facts (or moral truths), and these facts (or truths) are mind-independent in some important way; (ii) cognitivism about moral discourse is true: that is, moral moral claims purport to describe moral facts (or moral truths), and (at least some of) these claims successfully do so; and (iii) moral knowledge is possible, and we have some of it. ~ ctdreyer