In this volume, John Wippel has collected a number of his essays dealing with Aquinas's metaphysical thought. The volume begins with a presentation and critical evaluation of certain twentieth-century attempts to describe the philosophical thought of Thomas Aquinas as a "Christian philosophy." The book is then divided into two major parts, with Part I devoted to Aquinas's usage of Avicenna in explaining the interrelationship between first philosophy and the other theoretical sciences, Aquinas's different reasons for naming metaphysics "first philosophy," and his appeal to a distinctive kind of intellectual operation--separation--in order to account for our discovery of being as being, or the subject of metaphysics.The chapters in Part II are directed to Thomas's argumentation for real distinction between essence and existence in created beings both as this is presented in the De ente et essentia and in many of his other writings. Thomas's views concerning the ontological status of nonexisting possibles are examined in a following chapter, along with the positions of Henry of Ghent and Godfrey of Fontaines. Chapters are then devoted to Aquinas's positions concerning the possibility of an eternally created universe, and our capacity to arrive at quidditative knowledge of God in the present life. A final chapter concentrates on the issues of divine knowledge, divine power, and human freedom in Aquinas and in Henry of Ghent.