It is human nature to want to exchange ideas, and I believe that, at bottom, every artist wants no more than to tell the world what he has to say. I have sometimes heard painters say that they paint 'for themselves': but I think they would soon have painted their fill if they lived on a desert island. The primary purpose of all art forms, whether it's music, literature, or the visual arts, is to say something to the outside world; in other words, to make a personal thought, a striking idea, an inner emotion perceptible to other people's senses in such a way that there is no uncertainty about the maker's intentions.