“The Viennese logicians worked out a system wherein everything is, as far as I understood it, a tautology, that is, a repetition of premises. In mathematics, it goes from a very simple theorem to a complicated one, but it’s all in the first theorem. So, metaphysics: tautology: religion: tautology; everything is tautology, except black coffee because the senses are in control! The eyes see the black coffee, the senses are in control, it’s a truth; but the rest is always tautology.”

(Marcel Duchamp, interview with Pierre Cabanne, trans. Ron Padgett)