Moral Uncertainty, by William MacAskill, Krister Bykvist and Toby Ord. Oxford University Press, 2020, viii + 226 pages

Abstract

We have all experienced ‘moral uncertainty’, in the sense of being unsure of the correct morality. Despite such uncertainty, we must make morally loaded decisions. Here is one obvious response: first, identify the moral theory you find the most plausible; then, make decisions as prescribed by this theory. But the monograph under review represents a recent literature that explores a different approach, based on maximizing expected choiceworthiness. For example, suppose I am invited to dinner, and I can order Meat or Tofu. If I order Tofu, it will hurt my host’s feelings. However, I am torn between two moral theories. I assign 95% credence to Theory X, which says it is okay to eat meat. But I assign 5% credence to Theory Y, which says meat is an atrocity. My moral decision problem can be described by the following table.