Abstract

Thomas Aquinas inherits two distinct conceptions of the virtuous human being. From Aristotle, he receives a vision of harmony and human achievement: through the process of habituation, the distinct parts of the virtuous soul are operating as one under the guidance of reason. From Augustine, Aquinas receives a vision of moral struggle and victory through divine assistance: the virtuous person is able to resist the inclinations of the flesh through virtues that are given by God and only fully actualized in the next life. This dissertation explores an underappreciated area of Aquinas’s thought—on the topic of growth in the infused virtues—where he brings these teachings of Aristotle and Augustine into a brilliant harmony. In order to fully understand and appreciate Aquinas’s teaching on growth in infused virtue, one must first understand the essence of the infused virtues and their increase. This is the goal of Chapters Two and Three. In Chapter Two, I explore Aquinas’s discussion of habits in the Summa Theologiae by tracing three important topics: the essence of habits, the cause of habits, and the increase of habits. In Chapter Three, I elucidate Aquinas’s teaching on the essence of the infused virtues and situate these important virtues within his picture of the flourishing human life. The fourth chapter lays out Aquinas’s teaching on growth in infused virtue. I develop a metaphysical account of increase in infused virtue and pay careful attention to the associated stages. The chapter concludes with a close examination of the important imperfections that Aquinas associates with the infused virtues. I demonstrate that growth in infused virtue—rather than the development of the acquired virtues —is an effective remedy for these imperfections. In the concluding chapter, I emphasize the ways in which Aquinas’s understanding of growth in infused virtue represents the deepest point of his harmony of Aristotle and Augustine. I also situate my project among two prominent interpretive trends in Thomistic literature and highlight two important implications of the project.