The supreme question about a work of art is out of how deep a life does it spring. James Joyce, from 'Ulysses'

This is an interesting statement by Joyce. 100 years earlier no-one would have thought of making it, because the 'depth' of an artist's life was reflected in the art itself; the two were inseparable. The works of Schubert or Baudelaire, for example, clearly reveal the depths of their creators' lives. By the early twentieth century that was no longer the case. Marcel Duchamp - and others - had moved the goalposts, making it often impossible to deduce anything at all about the artist by examining the work in isolation. 'Can one make works of art which are not art?' Duchamp asked in 1913, and proceeded to 'create' the ready-made. People would say, 'but anyone could do that?', and Duchamp would reply disarmingly, 'yes, but why would they want to?' In other words, 'how do their lives differ from mine?'