Augustine was also known as Aurelius Augustinius and Augustine of Hippo. He was born in Tagaste, a provincial Roman city in Algeria in North Africa. His upbringing exhibited a dual influence, since his mother, Monica, was a Christian and his father, Patricius, was a pagan. At age seventeen he headed to Carthage to pursue an education in rhetoric. He also lived a hedonistic lifestyle for a time. In Carthage he developed a relationship with a young woman who would be his concubine for over fifteen years, with whom he had a son. Before the age of twenty he had turned his back on Christianity, since his Christian ideas seemed inadequate to him. In particular, he was perplexed by the problem of moral evil. The Christians said that God is the creator of all things and that God is good. How, then, is it possible for evil to arise out of a world that a perfectly good God had created?

Because Augustine could not find an answer, he turned away from Christianity and toward the Manichees. His mother was horrified. Their philosophy of Manichaeism said that two principles — those of darkness, or evil, and the principle of light, or good — worked together in the universe. The two principles were equally eternal, but eternally in conflict with each other. Things grouped under evil — like excess sensual desires — could be attributed to this external power of darkness.

His mother kept after him to return to Catholicism, but it was the bishop of Milan, St. Ambrose, who exerted the greatest influence in this regard. A master rhetorician like Augustine, Ambrose was also older and more experienced. Influenced by Ambrose's sermons and other studies, Augustine turned from Manichaeism. His search for truth brought him to Plotinus (205–270), a neo-Platonic thinker and Christian who in his Enneads argued that man has cut himself off from God and must return to him to find eternal blessedness.

Augustine's mother hankered for him to return to Catholicism. Her efforts bore fruit in 386. When Augustine was 32 he underwent a conversion experience and decided to enter the Christian church. His Confessions reveal how he now rejected his libertine ways in Carthage and his life of debauchery, “seduced and seducing, deceived and deceiving in divers lusts.”

He returned to North Africa and lived in a monastic community for two years. After he was ordained he became assistant to Valerius, the Bishop of Hippo, and eventually succeeded him in the bishopric. He performed his clerical duties, preached, and travelled until his death in 430.