This dissertation examines Thomas Aquinas’s engagement with the Contra Faustum, the largest and most comprehensive of Augustine’s anti-Manichaean works, especially as it is deployed in Thomas’s teaching on the Old and New Law in the Summa theologiae’s treatise on law. Thomas first encountered the Contra Faustum through cited quotations in various twelfth- and thirteenth-century theological texts; but in the early 1260s, he gained direct knowledge of the Contra Faustum in its integrity, and it came to occupy an increasingly important role in the articulation of his thought. The significance of the Contra Faustum for Thomas emerges most clearly in his teaching on divine law, where he shows a unique grasp of what is most valuable about the work, judiciously adopting Augustine’s signature emphases as his own. Due the volume of cited uses of the Contra Faustum in his discussion of the Old and New Law, the work’s import for Thomas’s teaching has occasionally been noted, yet this has never been studied in detail, nor have the potential antecedents or originality of Thomas’s usage been explored.
The dissertation falls into three parts. Part I provides an introduction to the Contra Faustum, establishing a necessary background for considering Thomas’s use of it, and filling an existing gap in Augustine studies, where analysis of the work in its entirety is largely absent. Further background to Thomas’s use of the workis established in Part II, which tracks the Contra Faustum’s reception from Augustine’s lifetime up to that of Thomas, supplying what is at present the fullest medieval reception history of any single Augustinian work. The culmination of the dissertation comes in Part III, which provides a close reading of the treatise on law, exposing how the Contra Faustum shapes Thomas’s teaching, while attending to other textual influences, and to contested aspects of his teaching concerning Jews and Judaism, and his approach to the Old Testament more broadly. Analysis of this material yields rich gains for illuminating not only the extent of Augustine’s influence on Thomas, but also Thomas’s practices as reader and teacher, establishing his location—and distinction—within thirteenth-century scholastic theology.