 Augustine was perhaps the greatest Christian philosopher of Antiquity and certainly the one who exerted the deepest and most lasting influence. He is a saint of the Catholic Church, and his authority in theological matters was universally accepted in the Latin Middle Ages and remained, in the Western Christian tradition, virtually uncontested till the nineteenth century. The impact of his views on sin, grace, freedom and sexuality on Western culture can hardly be overrated. These views, deeply at variance with the ancient philosophical and cultural tradition, provoked however fierce criticism in Augustine’s lifetime and have, again, been vigorously opposed in the twentieth and twenty-first centuries from various (e.g., humanist, liberal, feminist) standpoints. Philosophers keep however being fascinated by his often innovative ideas on language, on skepticism and knowledge, on will and the emotions, on freedom and determinism and on the structure of the human mind and, last but not least, by his way of doing philosophy, which is—though of course committed to the truth of biblical revelation—surprisingly undogmatic and marked by a spirit of relentless inquiry. His most famous work, the Confessiones, is unique in the ancient literary tradition but greatly influenced the modern tradition of autobiography; it is an intriguing piece of philosophy from a first-person perspective. Because of his importance for the philosophical tradition of the Middle Ages he is often listed as the first medieval philosopher. But even though he was born several decades after the emperor Constantine I had terminated the anti-Christian persecutions and, in his mature years, saw the anti-pagan and anti-heretic legislation of Theodosius I and his sons, which virtually made Catholic (i.e., Nicene) Christianity the official religion of the Roman Empire, Augustine did not live in a “medieval” Christian world. Pagan religious, cultural and social traditions were much alive in his congregation, as he often deplores in his sermons, and his own cultural outlook was, like that of most of his learned upper-class contemporaries, shaped by the classical Latin authors, poets and philosophers whom he studied in the schools of grammar and rhetoric long before he encountered the Bible and Christian writers. Throughout his work he engages with pre- and non-Christian philosophy, much of which he knew from firsthand. Platonism in particular remained a decisive ingredient of his thought. He is therefore best read as a Christian philosopher of late antiquity shaped by and in constant dialogue with the classical tradition.