Two letters, written by a minister of the Gospel to a gentleman, concerning professor Campbell's divinity : Letter I. Wherein his scheme concerning the origine, or primary source of moral virtue, contained in his answer to the author of the fable of the bees, is shewed to be irrational, and antiscriptural. Letter II. Wherein his discourse, proving that the apostles were no enthusiasts, is considered; and the poisonous nature of enthusiasm, together with his mistakes of it, are detected.