Coppies made by a Master after his Own Work are discoverable by being well acquainted with what that Master did when he followed Nature ; These shall have a Spirit, a Freedom, a Naturalness which even He cannot put into what he Coppies from his Own Work, as has been noted already.
An Essay on the whole art of criticism […] ; Of the Goodness of a Picture, &c., p. 193
RICHARDSON, Jonathan, Two Discourses. I. An Essay on the whole Art of Criticism as it relates to Painting. Shewing how to judge I. Of the Goodness of a Picture ; II. Of the Hand of the Master ; and III. Whether ‘tis an Original, or a Copy. II. An Argument in behalf of the Science of a Connoisseur ; Wherein is shewn the Dignity, Certainty, Pleasure, and Advantage of it. Both by Mr. Richardson, London, W. Churchill, 1719.