In the City of God Augustine uses a large variety of literary sources, and in a variety of ways. Some are cited in passing, others are repeatedly used; some are referred to by name, others may be inferred; in some cases, a specific use or influence is disputed by modern interpreters. This chapter collects and summarizes the literary influences upon Augustine in City, and the sources he used, often polemically. It contains sections on secular Latin writers, on Greek, mainly philosophical, writers in Latin translations, and on Jewish and Christian writers. The principal authors discussed are, in the first section, Varro, Cicero, Sallust, Virgil, and Apuleius; in the second section, Plato, Plotinus, and Porphyry; and in the third section, Origen, Eusebius, and Jerome.