David and Mary Norton present the definitive scholarly edition of one of the greatest philosophical works ever written. This first volume contains the critical text of David Hume's Treatise of Human Nature (1739/40), followed by the short Abstract (1740) in which Hume set out the key argumentsof the larger work; the volume concludes with A Letter from a Gentleman to his Friend in Edinburgh (1745), Hume's defence of the Treatise when it was under attack from ministers seeking to prevent Hume's appointment as Professor of Moral Philosophy at the University of Edinburgh.