Doctoral Dissertations

Date of Award


Degree Type


Degree Name

Doctor of Philosophy



Major Professor

Matthew Bryan Gillis

Committee Members

Jacob Latham, Sara Ritchey, Jay Rubenstein


This dissertation examines how late antique and early medieval Christians claimed a monopoly on rationality and how this self-understanding had affected their tolerance for confessional outsiders, namely pagans, heretics, and Jews. It reexamines how an intra-Christian debate, commonly known as the Semipelagian or Massilian Controversy, had a fundamental impact on early medieval conceptions of social tolerance for these confessional outsiders, at the dawn of the Early Middle Ages in one of the most significant post-Roman states in Western Europe, Merovingian Gaul. Earlier scholarship has examined this debate as solely esoteric and intellectual, concerned only with the role of good deeds and divine grace in the salvation of humanity. This study offers a new lens of examination and focuses on how the two main factions of the debate understood the human capacity for reason and its implications for social policy and tolerance for the other. Though both factions understood faith and reason to be forms of God’s divine grace and to exist together along a continuum, there were crucial differences. The Semipelagians or the synergists understood all humans to have a capacity for rationality, but considered it damaged after the Fall of Adam and Eve, the Fall of Humanity. In their view, Christians were the most rational, but those outside the Christian fold were capable of being rational, performing intrinsically good deeds, and being trustworthy neighbors. The Augustinians or predestinarians, meanwhile, considered human nature and the capacity for reason to be totally depraved after the Fall. Only those predestined by God before time itself would have their rational capacity restored and become true Christians. Those outside this divine election were not only foredamned, but also irrational, beastly, and untrustworthy neighbors. Both factions sought to inculcate their views of Christian community and its tolerance of others among wider laity. This study is the first to argue for the social impact of this well-known theological debate at both the elite and wider levels. It also argues that the question of social tolerance and persecution was one that lay at the very origins of the Middle Ages, not later, as has been commonly argued.

Available for download on Tuesday, May 15, 2029

Files over 3MB may be slow to open. For best results, right-click and select "save as..."