Work at the same time upon water, sky, branches, ground, keeping everything going on an equal basis and unceasingly rework until you have got it. Pai… - Camille Pissarro

advice to a young painter, (1896); as quoted in Painting Outside the lines, Patterns of Creativity in Modern Art, ed. David W. Galenson, Harvard University Press, 30 Jun 2009, pp. 84-85, note 40.

I have just concluded my series of paintings, I look at them constantly. I who made them often find them horrible. I understand them only at rare moments, when I have forgotten all about them, on days when I feel kindly disposed and indulgent to their poor maker. Sometimes I am horribly afraid to turn round canvases which I have piled against the wall; I am constantly afraid of finding monsters where I believed there were precious gems !.. .Thus it does not astonish me that the critics in London relegate me to the lowest rank. Alas! I fear that they are only too justified! - However, at times I come across works of mine which are soundly done and really in my style, and at such moments I find great solace. But no more of that. Painting, art in general, enchants me. It is my life. What else matters?

I recognize fully that you do not draw well, my dear Lucien [his son, also painter]. I told you any number of times that it is essential to have known forms in the eye and in the hand. It is only by drawing often, drawing everything, drawing incessantly, that one fine day you discover to your surprise that you have rendered something in its true character.