Sociologist Nathalie Heinich draws a distinction between modern and contemporary art, describing them as two different paradigms which partially overlap historically. She found that while "modern art" challenges the conventions of representation, "contemporary art" challenges the very notion of an artwork. She regards Duchamp's "Fountain" (which was made in the 1910s in the midst of the triumph of modern art) as the starting point of contemporary art, which gained momentum after World War II with Gutai's performances, Yves Klein's monochromes and Rauschenberg's "Erased de Kooning Drawing".