Augustine looked for wisdom beyond what he could find in the pagan philosophy of antiquity, whose principal luminaries have given philosophy its venerable, if remote, parentage. When seen through the prism of his theology of grace, this parentage is difficult for us to make out, for it has been transfigured by interests that seem alien to its origins. We are less sure of Augustine's midwifery in philosophy than we are of his paternity in theology. For the young man who read Cicero's Hortensius and burned with enthusiasm for philosophy defended, as an old bishop, a wisdom remarkably different from the one Cicero sought to impart to Latin culture. Augustine's break with ancient philosophy earned him his undisputed place at the foundations of medieval theology and culture, but it also roused the suspicion that his rejection of classical learning in favor of the revealed order of Scripture indicated a break from philosophy itself.

There have been few willing to accept Augustine's development of his doctrine of sin and grace as commensurable with the philosophical investigations of the pagan schools of antiquity. The various schools that come under fire in De civitate Dei – the Platonists, Peripatetics, Stoics, and Skeptics (novi Academici) – all depend on reason for illumination. Augustine, for his part, darkens reason with sin and insists on tying the human quest for knowledge to the influence of divine power upon human willing.