This is the last Book that tells the story of Augustine's life. The remaining Books concern spiritual matters and Biblical exegesis.
Augustine decided to resign from his post as Teacher of Rhetoric, but elected to wait until the beginning of the next vacation to inform his pupils and their parents. He felt that this was cowardly on his part even though he originally did it to avoid ostentation, and during the remainder of the semester he was tormented with a horrible toothache, which he assumed was a punishment from God. He experienced no difficulty, however, in deciding to put away his earthly profession: he had grown tired of his job as a "salesman of loquacity" and wanted to concentrate on spiritual matters.
After becoming unemployed, Augustine devoted himself to the study of scripture and wrote dialogues that explicated Neoplatonist Christianity while recovering from a lung complaint at a villa in Cassiciacum. He still had not let go of a small amount of earthly vanity, however, since in retrospect he regards these works as prideful and vain. Augustine read the Psalms frequently during this period; he was fond of quoting them, and had an ecstatic reaction to them.
On Easter Day of the year 387 Augustine was baptized by Bishop Ambrose. His son Adeodatus was there, as was Alypius. Augustine states that he is amazed at the boy's intelligence. This, he says, is all the work of God, since he contributed only his sin to Adeodatus. It becomes clear now that Augustine's concubine, Adeodatus' mother, was probably a Catholic because Adeodatus was already instructed in the faith. Augustine does not take any credit for his son's intelligence, though it was he who educated him.
Augustine praises his mother, saying she was not only devout and humble, but also wise. She was able to make peace with his father Patrick, who was a decidedly short-tempered man. Though he was a difficult man who sometimes jeered at her faith, Monica persuaded Patrick to be baptized before his death. Augustine also intimates that perhaps Monica was made for a higher purpose; namely, to help convert Augustine.
Augustine recounts much of Monica's life, including her brush with alcoholism as a girl and her extremely conservative views on marriage. She had borne the pain of a difficult and philandering husband, but had done so calmly because she considered the marriage contract to be binding. He praises her mildness and the mercy she showed to all those around her.
On their way home to Africa Monica and Augustine stopped in the port town of Rome, Ostia, where they had an ecstatic vision. They had been discussing the rewards of heaven, and came to the conclusion that the sensory pleasures of earth would be nothing compared to the pleasures found in heaven. In this moment of revelation, they believed that they knew how the rewards of God would feel in the afterlife. The important theological point here is that if the soul is at one with God, God will speak through the soul. Shortly after this episode, Monica fell ill. After nine days of illness, during which Monica told her son to bury her in Ostia, she died at the age of 56. Augustine says "my soul was wounded, and my life as it were torn in pieces, since my life and hers had become a single thing."
Augustine felt extraordinary pain at his mother's death but resolved not to grieve too greatly, for she had gone home to God. He cannot say why he was so saddened by her death, but threw himself on God's mercy, asking for comfort. He says that it is fitting to weep before God and rely on his infinite compassion.
Some of the events Augustine recounts in this Book reveal the vast differences between our world and ancient Roman society. For example, the point where Augustine states that he cannot say why he is sad at his mother's death seems slightly disingenuous. Who wouldn't grieve at their mother's death? His refusal to be maudlin or sentimental about an event that he feels every good Christian should rejoice at (the death of a faithful person in a state of grace) speaks to the totality of his conversion to the faith. However, he seems to feel that since he is now a Catholic he is no longer a man or a son. He had battled with his mother in the past, and she may have interfered in some aspects of his life, but overwhelmingly she was a source of enormous support for him.
This attitude may partially arise from Augustine's continued haughtiness. He has on more than one occasion spoken of women as "weak" and beneath him, so he cannot revere his mother, however devout she may be, as a person on the same level as himself. He praises her throughout this Book, but is also quick to point out her shortcomings. No doubt this can be interpreted in a Freudian way, but he seems both to love his mother and to despise her. From a modern perspective, this may seem to be the natural response of a man who lives with his mother well into his adulthood and has been shepherded into her intensely religious life.
Monica's views on the total subjugation of wives were not only completely in sync with the writings of St. Paul, but were also characteristic of the period. Marriage in those days was completely under the control of the husband, and there were no laws to protect her from physical violence at her husband's hands. Her policy of mildness and peace may have stemmed partially from her faith, but was also the product of a mind that was wise enough to choose the path most likely to facilitate her survival. Patrick, we are told, was a violent man, and early in their marriage she might have discovered that the only way to placate him was to submit to his wishes. She never criticized Patrick about his unfaithfulness, a fact for which Augustine praises her. This sort of double standard regarding sexual matters was common at the time.
This view of marriage seems extreme today even by conservative standards. The Roman world, however, was highly patriarchal. The husband and father was the paterfamilias: he was not only the head of household, but also had the power of life and death over the members of his household. He could sell his children into slavery, or kill them if he so chose. This kind of institutionalized familial tyranny would have motivated women and children to be particularly careful about what they said and did. It is not surprising that Monica never chided her husband for his adultery - to do so could have given him reason to beat her or their children to death. By Augustine's day the rights of the paterfamilias had weakened somewhat, but there were still no domestic violence laws, and women had no legal rights. To a woman like Monica, Christianity's message of peace and escape from worldly cares would have been particularly attractive.
The shared vision at Ostia showed that Augustine was finally letting go of the last of his Manichean "heresies." Some Manichees believed that the soul was part of God - in this episode Augustine is quick to point out that the soul is separate from God, but God can communicate with the soul if the soul is at one with Him. It was this sort of Catholic paradox (or "mystery") that Augustine struggled with prior to his conversion.