The first fruits of the literary career of St. Augustine, the great theologian and Christian philosopher par excellence, are the dialogues he wrote at Cassiciacum in Italy following his famous conversion in Milan in 386 AD. These four little books, largely neglected by scholars, investigate knowledge, ethics, metaphysics, the problem of evil, and the intriguing relationship of God and the soul. They also take up the ancient philosophical project of identifying the principles and practices that...