Acknowledged as the "Artist of the Century," Marcel Duchamp (1887-1968) left a legacy that dominates the art world to this day. Inventing the ironically degage attitude of "ready-made" art-making, Duchamp heralded the postmodern era and replaced Pablo Picasso as the role model for avant-garde artists. John F. Moffitt challenges commonly accepted interpretations of Duchamp's art and persona by showing that his mature art, after 1910, is largely drawn from the influence of the occult traditions. Moffitt demonstrates that the key to understanding the cryptic meaning of Duchamp's diverse artworks and writings is alchemy, the most pictorial of all the occult philosophies and sciences.