 Whereas modern discussion tends to regard faith and reason as alternative or even mutually exclusive ways to (religious) truth, in Augustine’s epistemological and exegetical program the two are inseparable. He rejects the rationalism of the philosophers and, especially, the Manicheans as an unwarranted over-confidence into the abilities of human reason resulting from sinful pride and as an arrogant neglect of the revelation of Christ in Scripture (De libero arbitrio 3.56; 60; Confessiones 3.10–12). Against the fideism he encountered in some Christian circles (cf. Letter 119 from Consentius to Augustine) he insisted that it was good and natural to employ the rational capacity we have been created with to search for an understanding of the truths we accept from the authority of the biblical revelation, even though a true understanding of God will only be possible after this life when we see him “face to face” (Letter 120.3–4). In this epistemological and exegetical program, which since Anselm of Canterbury has aptly been labeled as “faith seeking understanding” (cf. De trinitate 15.2: fides quaerit, intellectus invenit) or “understanding of faith” (intellectus fidei), faith is prior to understanding in time but posterior to it in importance and value (De ordine 2.26; De vera religione 45; Letter 120.3; van Fleteren 2010). The first step toward perfection is to believe the words of Scripture; the second is to realize that the words are outward signs of an internal and intelligible reality and that they admonish us to turn to and to “consult” inner truth so as to reach true understanding and, accordingly, the good life (cf.  5.2 Illumination;  5.4 Language and Signs).  Philosophical argument may be of help in this process; yet as Augustine notes as early as in Contra Academicos (3.43), it needs to be tied to the authority of Scripture and the Creed to prevent the frailty of human reason from going astray (cf. Confessiones 7.13). The Augustine of the earliest dialogues seems to have entertained the elitist idea that those educated in the liberal arts and capable of the Neoplatonic intellectual ascent may actually outgrow authority and achieve a full understanding of the divine already in this life (De ordine 2.26, but contrast ib. 2.45 on Monnica). In his later work, he abandons this hope and emphasizes that during this life, inevitably characterized by sin and weakness, every human being remains in need of the guidance of the revealed authority of Christ (Cary 2008b: 109–120). Faith is thus not just an epistemological but also an ethical category; it is essential for the moral purification we need to undergo before we can hope for even a glimpse of true understanding (Soliloquia 1.12; De diversis quaestionibus 48; De trinitate 4.24; Rist 2001). To a great extent, Augustine’s defense of faith as a valid epistemic category rests on a rehabilitation of true belief against the philosophical (Platonic and Hellenistic) tradition. Augustine neatly distinguishes “belief” (fides, the word he also uses for religious faith), which entails the believer’s awareness that he does not know, from “opinion” (opinio), defined by the philosophers as the illusion of knowing what one in fact does not know (De utilitate credendi 25; Letter 120.3). Without belief in the former sense, we would have to admit that we are ignorant of our own lineage (Confessiones 6.7) and of the objects of the historical and empirical sciences, of which, as Augustine asserts in a critique of Platonism, first-hand knowledge is rarely possible (De trinitate 4.21). The belief that a person we have not seen was or is just may trigger our fraternal love for him (De trinitate 8.7; Bouton-Touboulic 2012: 182–187; conversely, Augustine asks those who are united with him in fraternal love to believe what he tells them about his life, Confessiones 10.3). And obviously, the crucial events of the history of salvation, Jesus’ death on the cross and his resurrection, cannot be known but only believed qua historical events, even though qua signs they may lead to understanding by prompting us to an intelligible truth (De trinitate 13.2). Thus, while no doubt faith in revelation precedes rational insight into its true meaning, the decision about whose authority to believe and whom to accept as a reliable witness is itself reasonable (De vera religione 45; Letter 120.3). Even so, belief may of course be deceived (De trinitate 8.6). In ordinary life, this is inevitable and mostly unproblematic. A more serious problem is the justification of belief in Scripture, which, for Augustine, is the tradition and authority (auctoritas, not potestas) of the Church (Contra epistulam fundamenti 5.6; Rist 1994: 245).