The twentieth century witnessed an explosion of scholarly interest in the philosophical thought of St Thomas Aquinas. One of the fruits of that Thomistic revival was an uncovering of St Thomass original contributions to many areas of philosophy, not least metaphysics. In the twenty first century, there has been renewed interest in Aquinass argumentation for the existence of God. This interest flows from an engagement with the work of the twentieth century scholars in presenting Aquinass own characteristic metaphysics. What we have seen is an interpretation and presentation of Aquinass proofs for Gods existence in terms of Thomass unique insights into the nature of being and the metaphysical structure of reality. Gaven Kerr has been one such author who has contributed in numerous ways to the revival of interest in Aquinass argumentation for the existence of God and its metaphysical buttressing. Over the last ten years Kerr has published articles on Aquinass various proofs for Gods existence and the metaphysics standing behind those proofs; this volume draws together those articles. Herein are included Kerrs articles on per se ordered series, existential inertia, the proof in De Ente et Essentia, the argument from motion in the Summa Contra Gentiles, and the five ways themselves. Kerr has also written two new articles for this volume: one on the possibility of demonstrating Gods existence, and the other on how to move from Gods existence to Gods nature. This volume offers an overview of Kerrs thinking over the last decade on Aquinass thought on the existence of God.