I [Boswell] was somewhat disappointed in finding that the edition of The English Poets, for which he was to write Prefaces and Lives, was not an undertaking directed by him: but that he was to furnish a Preface and Life to any poet the booksellers pleased. I asked him if he would do this to any dunce's works, if they should ask him.
JOHNSON: "Yes, Sir, and say he was a dunce."
September 14, 1777, p. 341 - Life of Samuel Johnson (1791) - Vol III