An artist must be unusually intelligent in order to grasp simultaneously many structured relations. In fact, intelligence can be considered as the capacity to grasp complex relations; in this sense, Leonardo’s intelligence, for instance, is almost beyond belief. Duchamp’s intelligence contributed many things, of course, but for me its greatest accomplishment was to take him beyond the merely “aesthetic” concerns that face every “modern” artist - whose role is neither religious nor communal, but instead secular and individual. This problem has been called “the despair of the aesthetic:” if all colors or nudes are equally pleasing to the eye, why does the artist choose one color or figure rather than another? If he does not make a purely “aesthetic” choice, he must look for further criteria on which to base his value judgments. Kierkegaard held that artistic criteria were first the real of the aesthetic, then the ethical, then the realm of the holy. Duchamp, as a nonbeliever, could not have accepted holiness as a criterion but, in setting up for himself complex technical problems or new ways of expressing erotic subject matter, for instance, he did find an ethic beyond the “aesthetic” for his ultimate choices. And his most successful works, paradoxically, take on that indirect beauty achieved only by those artists who have been concerned with more than the merely sensuous. In this way, Duchamp’s intelligence accomplished nearly everything possible within the reach of a modern artist, earning him the unlimited and fully justified respect of successive small groups of admirers throughout his life. But, as he often says in the following pages, it is posterity who will judge, and he, like Stendhal, had more faith in posterity than in his contemporaries. At the same time, one learns from his conversations of an extraordinary artistic adventure, filled with direction, discipline, and disdain for art as a trade and for the repetition of what has already been done.