In “Ethical Theory: An Anthology”, Russ Shafer-Landau includes an article of Michael Smith’s arguing for moral realism. This article gives some constructive thought to moral realism, with some exceptional points on the flaws of the standard picture of human psychology, yet its final reasoning for why one should believe in the objectivity of moral facts is flawed.
Smith argues that moral disagreements might be useful to his philosophy, only insofar as that they can morph into moral agreement. Smith shows multiple times throughout the article that there are many different reasons for believing in moral facts, but without absolute proof. He admits that many philosophers believe in the possibility that our reasons for action, and so the moral truths upon which we base those actions, are fundamentally relative, differing from person to person. Even so, he pushes for his view, arguing that the answer might lie in the result of a moral disagreement. If one moral disagreement can end in such a way that person “A” has convinced person “B” that the belief of “A” is correct, then it is possible that person “B” was mistaken in their original belief and that person “A” had true knowledge of the moral fact in question.
The tricky bit about this journey towards truth, argues Smith, is that it would imply that everyone’s views could eventually converge on the moral truth at hand. This is the weak link in the argument. If convergence upon a belief were data in favor of realism, then one could use the argument in favor of the existence of the Judeo-Christian God. Not having studied religion extensively, I cannot delve into the details with any accuracy, but I am fairly certain that people have convinced other people to convert religions in the history of the world. If everyone were to converge upon a single God, would Smith argue that this is evidence for truth in the matter of the fact of God’s existence? As Smith discounts the idea of the Judeo-Christian God in the article, I would venture to guess that the answer is “no”. Perhaps my analogy between his argument for moral facts and an argument for the existence of god is far-fetched, but certainly no more far-fetched than the argument itself. One might argue that the world’s population has never believed in the same God…but the same population has probably been closer to a uniform belief in God than it has been to a belief in objective moral truths.