Harman is interested in the comparison between moral beliefs and the beliefs that we get through the natural sciences. He argues that there is a significant difference between the two.
I made some picky points about the wording of Harman’s arguments. And I said that I didn’t think he had proven his point. But I concluded that there are good reasons to suspect that he might well be right. If so, moral rules are the product of social custom. In our next several sessions, we will explore what, if anything, might follow from that.
I criticized the following way of making Harman’s point. “We need to assume that objective facts explain observations in the sciences. But we do not need to make a similar assumption to explain moral observations. Moral observations can be explained by social learning, which could lead us to believe things that have no basis at all in fact.”
What’s wrong with that? Well, you don’t need to assume that scientists observe facts in order to explain why they make the observations that they do. After all, many scientists have been making observations that reflect their training more than objective facts. Some of them are doing it right now, though we won’t know who for another several hundred years.
A better way to make the point is to say that the best explanation of observations in the sciences is that, in the main, they reflect objective facts. By contrast, the argument goes, the best explanation of moral beliefs is that they reflect social training rather than objective fact.
I said that I don’t think this has been proven. But the successes of the sciences suggests that it might well be true.