Happiness is a terrible frail foundation on which to build any theory of life; and it seems to the plain man that happiness cannot be the ultimate goal because it has so often to be sacrificed for something better than itself. Virtue, or moral goodness, is too purely a human thing; and has to much the air of a means to an end beyond itself. Beauty is in things human and non-human, and seems almost omnipresent in the natural world. Now, if we ask Aristotle or Plato why a man should act righteously, or why he ought sometimes to sacrifice his happiness or to welcome martyrdom, they will answer, in a language which to a Greek is perfectly simple though possibly strange to us, that he should do so ἕνεκα τοῦ καλοῦ, "for the sake of the beautiful." (...) It is always a comfort to me that Shelley in his writings about poetry assumes as matter of course that there is beauty in human action and thought just as much as in a picture or a landscape. He does not see, as I confess I have never been able to see, though people have tried to point it out for me for forty years, any real difference between the moral and the aesthetic. And if we take the best-developed and most genuinely popular art of the present day, the novel, I think we shall find that it is predominantly interested and occupied in representing beauty and ugliness in the sphere of human character. There is no subject about which most of us have such keen perception and such strong feelings. I believe as a matter of fact, amid the immense variety of religious, moral and social beliefs in which we live, and the marked weakening of many of them, that the actual motive that works most genuinely among good men and women is this avoidance of the conduct which they feel to be ugly and this love of that which they feel to be "fair" or "decent" or "straight" or some other of those modest synonyms which in our shyness we use instead of the word "beautiful".
Gilbert Murray, The Classical Tradition in Poetry, Oxford University Press, 1937.