What was the truth for the painters of yesterday is but a falsehood today. We declare, for instance, that a portrait must not like the sitter... To paint a human figure, you must not paint it; you must render its surrounding [aura-like] atmosphere. Space no longer exists... Who can still believe in the opacity of bodies, since our sharpened and multiplied sensibilities has already penetrated the obscure manifestations of mediums? Why should we forget in our creations the doubled power of our sight, capable of giving analogous to those of X-rays?

As quoted in: John F. Moffitt (2003) Alchemist of the Avant-Garde: The Case of Marcel Duchamp, p. 87. - 'Manifesto of Futurist Painters,' April 1910