You think then, that I know my profession? Why, my poor fellow; if I had nothing more to find out and to learn I could not paint any longer.

as quoted by Albert Wolff, 1880's, in Notes upon certain masters of the XIX century, - printed not published MDCCCLXXXVI (1880's), The Art Age Press, 400 N.Y. (written after the exhibition 'Cent Chefs-d'Oeuvres: the Choiche of the French Private Galleries', Petit, Paris / Baschet, New York, 1883, p. 36

Dupré is responding in this quote to a purchaser who was teasing him to finish a picture only in a few hours. Dupré replied in the presence of Albert Wolff