This volume is a tribute to Fr. John F. Wippel. Following the philosophical order that Aquinas might have adopted "had he chosen to write a Summa metaphysicae "?an order that Wippel himself lays out in his Metaphysical Thought of Thomas Aquinas ?these essays unfold new research on some of the most intriguing topics in Aquinas's metaphysics, from the most recent generation of scholars formed by Wippel's pioneering work. The contributors address the discovery of being qua being via separation (Gregory T. Doolan), propter quid metaphysical demonstrations (Philip Neri Reese), the origins of the controversies about the real distinction between essence and esse (Mark Gossiaux), a defense of essence-realism as a key to the real distinction (David Twetten), the relationship of likeness and agency (Therese Scarpelli Cory), created form as act and potency (Stephen Brock), the variation of accidental forms (Gloria Frost), the possibility of angelic judgment (Francis Feingold), argumentation for the existence of God (Gaven Kerr), the propriety of " Qui Est " as a Divine Name (Brian Carl), 'Beauty' as a Divine Name (Michael Rubin), and God's application of creaturely powers to action (Jason Mitchell).