In the past artists represented things they had seen on earth, things they liked seeing or might have liked to see. Today, they reveal the relativity of visible things, they express their belief that the visible is only an isolated aspect in relation to the universe as a whole, and that other invisible truths are the overriding factors. Things appear to assume a broader and more diversified meaning, often seeming to contradict the rational experience of yesterday. The artist strives to express the essential character or the accidental.

Paul Klee, Berlin, 1920.