.. of what use is a painting which does not realize its aesthetical problem? Underlying all sensible works of art, there must be somewhere in evidence the particular problems understood. It was so with those artists of the great past who had the intellectual knowledge of structure upon which to place their emotions. It is this structural beauty that makes the old [clssical] painting valuable. And so it becomes to me a problem. I would rather be sure that I had placed two colors in true relationship to each other than to have exposed a wealth of emotionalism gone wrong in the name of richness of personal expression... The real artists have always been interested in this problem, and you feel it strongly in the work of [Leonardo] Da Vinci, Piero della Francesca, Courbet, Pissarro, Seurat, and Cezanne.