Cézanne: You can never be too scrupulous, too sincere, or too submissive to nature, while still remaining more or less in control of your subject and especially of your means of expression. You must adapt these to your motif. Not bending it your way but bowing to it. Allowing it to be born, to germinate within you. Painting what is in front of you and persevering in expressing yourself as logically as possible, but a natural logic, of course; I have never done anything else. You have no idea what discoveries await you then. You see, it's only through nature that you can make progress, and the eye educates itself by contact with nature. By dint of looking and working, it becomes concentric.
Myself: How do you mean, concentric?
Cézanne: I mean that on this orange I’m peeling or, indeed, on an apple, a ball, or a head, there is a culminating point, and despite tremendous effects – light, shade, colour sensations – this point is always the one nearest our eye. The edges of objects recede towards another placed on your horizon. Once you've understood that...
Oh well, you'd have to be a painter to understand. Good heavens, I've invented enough theories about it!
He took a piece of crumpled paper out of his pocket.
I’ve written to a painter who came to see me, someone you don't know, who does a bit of theorizing himself. I’ll sum up what I said to him in my letter.
He read in a drawling, timid but dogmatic voice:
'Treat nature in terms of the cylinder, the sphere, and the cone, the whole put into perspective so that each side of an object, or of a plane, leads toward a central point. Lines parallel to the horizon give breadth, whether a section of nature or, if you prefer, of the spectacle which Pater omnipotens aeterne Deus unfolds before your eyes. Lines perpendicular to this horizon give depth. Now, nature, for us human beings, has more to do with depth than with surfaces, hence the need to introduce into our vibrations of light, represented by reds and yellows, a sufficient quality of blue tints to create the impression of air.'
Yes... I make a better job of painting than writing, don't I? I'm not going to outdo Fromentin yet.
He crumpled the paper into a ball and threw it away. When I picked it up, he shrugged his shoulders.
Joachim Gasquet, Cézanne, A Memoir with Conversations