There is not less wit nor invention in applying rightly a thought one finds in a book, than in being the first author of that thought. Cardinal du Perron has been heard to say that the happy application of a verse of Virgil has deserved a talent.
Pierre Bayle, Works, Volume II, p. 779; in Hoyt's New Cyclopedia Of Practical Quotations (1922), p. 653-54: About quotation.