a French artist (he became an American citizen in 1955) whose work and ideas had considerable influence on the development of post-World War II Western art, and his advice to modern art collectors helped shape the tastes of the Western art world. His influence continues into the 21st century. While he is most often associated with the Dada and Surrealism movements, his participation in Surrealism was largely behind the scenes, and after being involved in New York Dada, he barely participated in Paris Dada. Thousands of books and articles attempt to interpret Duchamp's work and philosophy, but in interviews and his writing Duchamp only added to the mystery. The interpretations interested him as creations of their own, and as reflections of the interpreter. A playful man, Duchamp prodded thought about artistic processes and art marketing, not so much with words, but with actions such as dubbing a urinal art and naming it Fountain, and by giving up art to play chess. He produced relatively few artworks as he quickly moved through the avant-garde rhythms of his time.The creative act is not performed by the artist alone; the spectator brings the work in contact with the external world by deciphering and interpreting its inner qualifications and thus adds his contribution to the creative act.