My subject, as you know, is Ethics and I will adopt the explanation of that term which Professor Moore has given in his book Principia Ethica. He says: “Ethics is the general inquiry into what is good.” Now I am going to use the term Ethics in a slightly wider sense, in a sense in fact which includes what I believe to be the most essential part of what is generally called Aesthetics. And to make you see as clearly as possible what I take to be the subject matter of Ethics I will put before you a number of more or less synonymous expressions each of which could be substituted for the above definition, and by enumerating them I want to produce the same sort of effect which Galton produced when he took a number of photos of different faces on the same photographic plate in order to get the picture of the typical features they all had in common. And as by showing to you such a collective photo I could make you see what is the typical–say–Chinese face; so if you look through the row of synonyms which I will put before you, you will, I hope, be able to see the characteristic features they all have in common and these are the characteristic features of Ethics. Now instead of saying “Ethics is the enquiry into what is good” I could have said Ethics is the enquiry into what is valuable, or, into what is really important, or I could have said Ethics is the enquiry into the meaning of life, or into what makes life worth living, or into the right way of living. I believe if you look at all these phrases you will get a rough idea as to what it is that Ethics is concerned with.