North.—What is the trouble about moral facts? When someone denies that there is an objective moral order, or asserts that ethical propositions are pseudo-propositions, cannot I refute him (rather as Moore refuted those who denied the existence of the external world) by saying: “You know very well that Brown did wrong in beating his wife. You know very well that you ought to keep promises. You know very well that human affection is good and cruelty bad, that many actions are wrong and some are right”?
West.—Isn't the trouble about moral facts another case of trouble about knowing, about learning? We find out facts about the external world by looking and listening; about ourselves, by feeling; about other people, by looking and listening and feeling. When this is noticed, there arises a wish to say that the facts are what is seen, what is heard, what is felt; and, consequently, that moral facts fall into one of these classes. So those who have denied that there are “objective moral characteristics” have not wanted to deny that Brown's action was wrong or that keeping promises is right.