Every decision visible in a work of art bears witness to the rejection of something else. What we see is not only the result of determined assertions—“I will do this” or “I will allow this to remain”—but also the result of equally determined refusals—“I will not do that” or “I will obliterate that.” Yet there are artists who are unwilling to deny themselves anything, whose fertile minds and potent intuition present them with apparently endless alternatives, all of which demand to be explored. Pablo Picasso, Hans Hofmann, David Smith, and Anthony Caro exemplify this kind of artist. None of them ever settled for the familiar, the known, or the comfortable. Instead, throughout their lives as artists, they have all insisted on following the implications of each of their works as they evolved, no matter how far that might take them in an unforeseen and perhaps unwanted direction. It’s as if they constantly posed the question “What if, instead of what I have done already, I do that?” All of them have adopted, at different times, a great range of materials and embraced, at different times, various degrees of abstractness and allusion. Yet in their work, in contrast to other artists’ histories, such changes do not signify the transformation of the maker’s conviction that art is a more or less faithful reflection or interpretation of what can be seen into the belief that art is a revelation of the unseen. Instead, these artists have often