The purer the artist's 'mirror' is, the more true reality reflects in it. Overseeing the historical culture of art, we must conclude that the mirror only slowly is purified. Time producing this purifying shows a gradual, more constant and objective image of reality.
Piet Mondrian, Harry Holtzman, Martin S. James (1986). “The new art--the new life: the collected writings of Piet Mondrian”, Twayne Pub