Book VI of this autobiographical text concerns the issue of sex and women, and how Augustine had to change his views from being a young man in love with women and sex to agreeing to adapt his lifestyle and habits in accordance with the teachings of the church, which stated that you should only enjoy sexual relations within the context of a marriage. At the time, Augustine reflects that he was a slave to lust in his need to have sex and his inability to abandon his hedonistic pursuits. Note how he comments on this, looking back at what he did after he sent his concubine away in order to prepare for marriage:
And so, since I was not a lover of wedlock so much as a slave of lust, I procured another mistress--not a wife, of course. Thus in bondage to a lasting habit, the disease of my soul might be nursed up and kept in its vigor or even increased until it reached the realm of matrimony. Nor indeed was the wound healed that had been caused by cutting away my former mistress; only it ceased to burn and throb, and began to fester, and was more dangerous because it was less painful.
Note the kind of language Augustine uses to describe his lust-seeking habits. He classifies it as a "wound," and this powerful metaphor is enhanced through Augustine's description of the way in which it "festers" when he satisfies his lustful desires and becomes more dangerous because it is less painful. The reader sees that Augustine's views about women and love are gradually moving more and more towards the church's view of women and love, though his flesh still exerts a power over his body that Augustine struggles against, as suggested through words like "bondage."