A painter must not only be of necessity an imitator of the works of nature... but he must be as necessarily an imitator of the works of other painters: this appears more humiliating, but is equally true; and no man can be an artist, whatever he may suppose, upon any other terms.
Discourse no. 6, delivered on December 10, 1774; vol. 1, p. 150. - Discourses on Art