This dissertation offers a systematic account of St. Augustine’s principles of interpretation, or hermeneutics. Chapter 1 treats the dialectic of Confessions XII and argues that Augustine privileges the intention of the human author of Scripture as the best possible meaning of the text that readers must try to find, though they can still find other valid interpretations as long as they are seeking the author’s intention. Chapters 2-4 then treat six principles that Augustine appeals to in his theory of Scriptural interpretation. Chapter 2 argues for an inherent connection between Augustine’s intentionalism and his starting claim that Scripture is true inasmuch as it is authored by God; it also discusses his first interpretive principle, by which he appeals to general and linguistic knowledge as a prerequisite for interpretation. Chapter 3 explains three principles that Augustine ties together in a series and bases on the content of Scripture: Christ’s command to love God and neighbor as the purpose of all Scripture; the role of “clearly stated” (aperte posita) passages in establishing the parameters for the moral and doctrinal content of Scripture; and the use of figurative interpretation in understanding all Scripture, but especially passages that are unclear or objectionable. Chapter 4 argues that Augustine also uses two sources outside of Scripture, the authoritative statements of the Church and the sure arguments of philosophy or science, to limit and to add to the possible meanings of Scriptural passages. Chapter 5 returns to the issue of the human writer's intention and its role in interpretation, comparing the account in De Doctrina Christiana and Confessions XII to the earlier one in De Utilitate Credendi, and then proposing a larger theory of the role of the writer’s intention in light of some of Augustine’s later works.