Marcel Duchamp, one of this century's pioneers, moved his work through the retinal boundaries which had been established with Impressionism into a field where language, thought and vision act upon one another. There it changed form through a complex interplay of new mental and physical materials, heralding many of the technical, mental and visual details to be found in more recent art.. .He declared that he wanted to kill art ('for myself') but his persistent attempts to destroy frames of reference altered our thinking, established new units of thought, a "new thought for that object".