All perfections of things pre-exist in the divine essence, yet it is entirely simple, without components. These seemingly opposed attributes of God are reconciled in Questions 3-6 of the First Part of the Summa theologiae, here newly translated and explained in line-by-line detail. Among topics receiving special attention are Aquinas's doctrine of participation, his conception of God as a subsisting act of being, and the distinction and order of transcendentals such as being, goodness, and beauty. Intended for advanced undergraduates, graduate students, and teachers, Aquinas on God's...