How to Decide Moral Questions Rationally

Abstract

Abstract IF we look back over the development of moral (and also of legal) philosophy over the past fifty years or so, we can see it as the unfolding of the consequences of a fundamental mistake. Almost the first thing that happened to me when I started doing moral philosophy was that I saw that it was a mistake. I have been trying ever since to make people see that it is a mistake. But I have not been very successful. Let me now try to explain again what the mistake is. It is the mistake of thinking that the only possible exercise of reason is in determining facts or discovering truths. That there can be practical as well as theoretical reason was a cardinal thesis of Kant; and Aristotle, with his concept of phronesis, or practical as opposed to theoretical wisdom, showed that he thought the same. But now nearly everybody, whether or not he calls himself a rationalist, seems to agree in thinking that if one wishes to be a rationalist (if, that is to say, one wishes to find a place for rationality in moral thinking), one has to be a descriptivist ( that is to say, one has to believe that there are moral facts to be discovered). This almost universal mistake has had the most harmful consequences in recent moral philosophy, which it is my purpose in this paper to explore.