ABSTRACT
In this lecture I am going to try to bring philosophy to bear on a practical problem. But before I start, I had better try to explain to you what I think philosophy is, and what reason I have for supposing that it could possibly have any bearing on any practical problem. I have to explain what it is, because people have used the word 'philosophy' in so many different ways that you will not understand, without an explanation, the precise sense in which I am using it. And I have to say why I think philosophy has a bearing on practical problems, because many people do not think so, and because once you understand how I am using the word 'philosophy' you may well ask yourselves how such an abstract subject could possibly have any practical bearing.
