20. These things I did not understand at that time, and I loved those inferior beauties, and I was sinking down to the very depths. And I said to my friends: "Do we love anything but the beautiful? What then is the beautiful? And what is beauty? What is it that allures and unites us to the things we love; for unless there were a grace and beauty in them, they could not possibly attract us to them?" And I reflected on this and saw that in the objects themselves there is a kind of beauty which comes from their forming a whole and another kind of beauty that comes from mutual fitness--as the harmony of one part of the body with its whole, or a shoe with a foot, and so on. And this idea sprang up in my mind out of my inmost heart, and I wrote some books--two or three, I think--On the Beautiful and the Fitting.(see note 105) Thou knowest them, O Lord; they have escaped my memory. I no longer have them; somehow they have been mislaid.