Gaven Kerr provides the first book-length study of St. Thomas Aquinas's much neglected proof for the existence of God in De Ente et Essentia Chapter 4. He offers a contemporary presentation, interpretation, and defense of this proof, beginning with an account of the metaphysical principles used by Aquinas and then describing how they are employed within the proof to establish the existence of God. Along the way, Kerr engages contemporary authors...