But I think we have to go one step further. Herskovits may have been right that science cannot confirm or prove moral judgments, principles, ideals, and so forth. But that isn't quite enough.

Is there any method that can prove moral principles to be true or binding? Wong's analysis of truth refers to the "rules" of a moral system. Can we prove those rules to be true or binding? Does that even make sense?

Or maybe we should back up a little. What might it mean to prove a moral principle?