Infra-thin is a concept that permeates Marcel Duchamp's entire oeuvre, a shorthand label for his life-long desire to overcome the distance between Signifier and signified. The best known of Duchamp's obsessions is La Mariée mise à nu par ses célibataires, même, also known as the Large Glass. In his own words a “hilarious” picture which he insisted was not a picture at all, this chapter argues that Large Glass is an elaborate map of what it means to be human. As the critic of cartography might have expected, its theme comes in two variations, one being the painting/sculpture itself, the other the notes that go with it. If there were no imagination Duchamp would never have completed his most dialectical and self-referential work, an entire wing of the Philadelphia Museum of Art. Duchamp used his Philadelphia connections to show how Plato's dialectic is a most profound affair, an engagement to be lived forwards and understood backwards, perhaps with the undefined goal of knowing thyself.
Keywords: infra-thin, Marcel Duchamp, Philadelphia Museum of Art, Plato, Large Glass, painting, map