"Paul Cézanne's painting is strictly painting, and its value is immense; but Van Gogh's painting has the Outsider's characteristic: it is a laboratory refuse of a man who treated his own life as an experiment in living; it faithfully records moods and developments of vision on the manner of a Bildungsroman."
January 1, 1970
https://en.wikiquote.org/wiki/Vincent_van_Gogh