He [Marcel Duchamp] entered this object [the 'Urinal' ready-made] into the museum and noticed that its transportation from one place to another made it into art. But he failed to draw the clear and simple conclusion that every man is an artist.

as quoted in Joseph Beuys and the Celtic Wor(l)d: A Language of Healing, by Victoria Walters, LIT Verlag Münster, 2012, p. 206 - after 1984, posthumous published