This second edition of David-Hillel Ruben s influential and highly acclaimed book on the philosophy of explanation has been revised and expanded, and the author has made substantial changes in light of the extensive reviews the first edition received. Ruben s views on the place of laws in explanation has been refined and clarified. What is perhaps the central thesis of the book, his realist view of explanation, describing the way in which explanation depends on metaphysics, has been updated and extended and engages with some of the work in this area published since the book s first edition.