But I still think there are differences between natural science and moral systems. We have said that ethical relativism allows that there may be two conflicting moral judgments that are both true. In such a case we have reached a fundamental disagreement and there is no rational method for eliminating either statement. This sort of impasse is much more rare in natural science than in ethics. Natural scientists agree on the great bulk of their statements and can often imagine ways to resolve the rest. If there are two conflicting statements, it is assumed that one is false. This is not at all like the situation in a relativistic ethics.

I conclude that if there is such a thing as moral knowledge, it is not the same as scientific knowledge. But what is it?