The spiritual failure of classic civilization.--Stoicism and Christianity.--Under the Antonines.--Clement of Alexandria.--Tertullian of Carthage.--Neoplatonism and Christianity.--In the era of Diocletian.--The Emperor Julian and his religion.--The old believers in Rome and the dusk of the gods.--The earlier stages of Augustine.--The two sons of Theodosius and Alaric the Goth.--Augustine's City of God.