Augustine's Confessions is a diverse blend of autobiography, philosophy, theology, and critical exegesis of the Christian Bible. The first nine Books (or chapters) of the work trace the story of Augustine's life, from his birth (354 A.D.) up to the events that took place just after his conversion to Catholicism (386 A.D.). Augustine treats this autobiography as much more than an opportunity to recount his life, however, and there is hardly an event mentioned that does not have an accompanying religious or philosophical explication. In fact, the events that Augustine chooses to recount are selected mainly with a view to these larger issues.
Born and raised in Thagaste, in eastern Algeria (then part of the Roman empire), Augustine enters a social world that he now sees as sinful to the point of utter folly. Grade school teaches questionable pursuits with misguided aims, and everywhere boys like Augustine are trained to devote themselves to transient, material pursuits rather than to the pursuit of God. As a student in Thagaste and then Carthage, Augustine runs amok in sexual adventures and false philosophies (most notably Manicheism). He sees this period of his life primarily as a lesson in how immersion in the material world is its own punishment of disorder, confusion, and grief.
The young Augustine does, however, catch a passion for the pursuit of Philosophical truth, learning the doctrines of Manicheism, skepticism, and Neoplatonism. This last philosophy will have a profound influence on him-- the Confessions are perhaps the most masterful expression of his intricate fusion of Catholic theology with Neoplatonic ideas.
Moving back to Thagaste, then back to Carthage again, and on to Rome and Milan, Augustine continues to wrestle with his doubts about what he has learned and with his budding interest in Catholicism, the faith of his mother, Monica. He also continues to pursue his career as a teacher of rhetoric (an occupation he later frowns upon as the salesmanship of empty words) and his habits of indulgence in sex and other pleasures of the sensual world. Things change in Milan, where Augustine finally decides that Catholicism holds the only real truth. Convinced of this but lacking the will to make the leap into a fully devoted life (including baptism and sexual abstinence), Augustine has a famous conversion experience in his Milan garden and becomes a devoted and chaste Catholic.
The last four Books of the Confessions depart from autobiography altogether, focusing directly on religious and philosophical issues of memory (Book X), time and eternity (Book XI), and the interpretation of the Book of Genesis (Books XII and XIII). Despite this apparent sudden shift in content, however, the Confessions are remarkably coherent as a whole; in making his autobiography a profoundly reflective one, Augustine has already introduced many of the same ideas and themes that receive a direct treatment in the last four Books. The unifying theme that emerges over the course of the entire work is that of redemption: Augustine sees his own painful process of returning to God as an instance of the return of the entire creation to God.
The form of the work corresponds closely to its aim and its content; the work is about the return of creation to God, it aims to inspire others to actively seek this return, and it takes the highly original form of a direct address to God from one being in his creation. In this context, it is also noteworthy that, for Augustine, "confession" carried the dual meanings of an admission of guilt and an act of praise.