In An Essay on the Nature and Conduct of thePassions and Affections, with Illustrations onthe Moral Sense, Francis Hutcheson answers thecriticism that had been leveled against his first bookInquiry into the Original of Our Ideas of Beauty andVirtue (1725). Together the two works constitute thegreat innovation in philosophy for which Hutcheson ismost well known.The first half of the Essay presents a rich moralpsychology built on a theory of the passions and anaccount of motivation, deepening and augmenting thedoctrine of moral sense developed in the Inquiry. The second half of the work, the Illustrations, is abrilliant attack on rationalist moral theories and is thefont of many of the arguments taken up by Hume andused to this day.As editor Aaron Garrett notes, In the EssayHutcheson provides his crucial argument againstHobbes and Mandeville, that not just egoistic self-preservation,but also benevolence, is an essentialfeature of human nature.Professor Garrett has constructed a criticalvariorum edition of this great work. Because there areno manuscripts of the work, this could be done only bycomparing all extant lifetime editions. Three sucheditions exist: those of 1728, 1730 (chiefly a reprint ofthe 1728 edition), and 1742. The Liberty Fund editioncollates the first edition with Hutchesons revision of1742.Francis Hutcheson was a crucial link between the continental Europeannatural law tradition and the emerging Scottish Enlightenment. Hence, he is a pivotal figurein the Natural Law and Enlightenment Classics series. A contemporary of Lord Kames and GeorgeTurnbull, an acquaintance of David Hume, and the teacher of Adam Smith, Hutcheson wasarguably the leading figure in making Scotland distinctive within the general EuropeanEnlightenment.Aaron Garrett is AssociateProfessor of Philosophy at BostonUniversity.Knud Haakonssen is Professor of Intellectual History and Director of the Centre for Intellectual History at the University of Sussex, England.