The Perfection of the Universe gives an account of the idea of the universe and its perfection in Aquinas's philosophy, but at the same time it provides an example of how a cosmology can be developed in a teleological framework. Although this is the cosmology of one who was first and foremost a theologian, the book tries to show how it was articulated philosophically and in relation to a particular model of the universe. As a contribution to the history of philosophy, and to Thomistic studies in particular, the book seeks to draw more attention to Aquinas's view of the world, which has been relatively neglected in favor of emphasis on his theory of knowledge and theory of being, and at the same time to show how it is integral to his very understanding of being. The book thereby brings out a dimension of rationality in Aquinas's philosophy that is often ignored, especially as it concerns creation as a whole and what Aquinas refers to as convenientia in this whole. The systematic nature of Aquinas's conception of the universe is highlighted by the author's attempt to reconstruct the movement of his thought. Thus Oliva Blanchette focuses not just on the universe or on perfection, but on the perfection of the universe as a unified idea that recurs frequently in both the philosophy and the theology of Aquinas and that has its own philosophical dynamic both as a logic and as an actuality. In doing so, he endeavors to correct misconceptions about Aquinas's idea of the universe, such as that found in Lovejoy's Great Chain of Being, and to show how the idea stands up philosophically even while being connected with a scientific model of the universe now viewed as obsolete.