The rectangular picture-plane indicates the starting point of Suprematism; a new realism of color conceived as non-objective creation. The forms of Suprematist art live like all the living forms of nature. This is a new plastic realism, plastic precisely because the realism of hills, sky and water is missing. Every real form is a world. And any plastic surface is more alive than a (drawn or painted) face from which stares a pair of eyes and a smile.

In: Artists on Art; from the 14th – 20th centuries, ed. Robert Goldwater and Marco Treves; Pantheon Books, 1972, London, p. 452