This volume in the Studies in Philosophy and the History of Philosophy series contains thirteen essays by Lawrence Dewan on metaphysics, the vision of reality from the viewpoint of being. While they take the form of interpretations of the thought of Thomas Aquinas, they are meant as a contribution to perennial philosophy, truth that transcends particular cultures and eras. Written over a period of 25 years, they range from an overall conception of the primary philosophical wisdom, to such particular subjects as the conception of substance in an evolutionary context; the natural seed of intellectual knowledge within the human being; the principle of causality; the immortality of the soul; and the real distinction between particular form and the act of being, crucial for our understanding of reality as created. The method combines close readings of and reflections on the texts of Thomas Aquinas and other relevant thinkers. Because the essays were written largely in response to the work of several prominent twentieth-century metaphysicians, they regularly offer alternative views on extremely fundamental issues. The distinctive contribution of this volume is its focus on the role of form among the various items in the ontological analysis. The most prominent Thomistic metaphysicians in the twentieth century laid great stress on the role of the act of being. Dewan's essays present what is essentially the same picture, but in a way that emphasizes the continuity between Christian philosophers and their predecessors in ancient Greece.