The Impressionists were the first [painters] to reject the absolute value of the subject and to consider its value to be merely relative... In Paul Cezanne's letters I notice ideas like these: 'Objects must turn, recede, and live. I wish to make something lasting from impressionism, like the art in the museums'....'For an impressionist, to paint after nature is not to paint the object, but to express sensations'....'After having looked at the old masters, one must take haste to leave them and to verify in one's self the instincts, the sensations that dwell in us.'

in 'Functions of Painting by Fernand Leger'; p. 11 - Contemporary Achievements in Painting, Fernand Leger (1914)