Truth as a Virtue: A Thomistic Framework for the Ethics of Lying and Truthtelling

Doctoral Dissertation


Is it ever permissible to tell a lie? What if no one is harmed as a result? What if it is necessary to save someone from danger? What does it mean for a lie to be permissible? Permissible according to whom? Or to what? Do all lies violate the commandment ‘You shall not bear false witness against your neighbor’? What does it mean to be truthful? Am I still being truthful if I try to mislead while technically adhering to the truth? How should we interpret the crisis of truth in the 21st century?

This project offers answers to these and related questions by viewing them through an unlikely lens: the writings of the medieval scholastic theologian, Thomas Aquinas. The project intervenes in current debates among moral theologians and philosophers, which focus almost exclusively on the question of whether lying always violates a moral norm. I draw upon Aquinas’s insights to argue that we must first develop a coherent notion of truthfulness before we can assess the morality of lying. This approach generates a more precise taxonomy of speech acts, demonstrating the ways in which these acts and their corresponding habits are opposed to the virtues of truth and justice.

The dissertation unfolds in two parts, each containing three chapters. In Part One, I offer an interpretation of Aquinas’s position on lying, as a vice opposed to the virtue of truth. Interpreters of Aquinas have paid insufficient attention to the virtue of veracitas, or truthfulness, and I demonstrate the creative ways in which he draws upon antique sources – primarily Augustine, Aristotle, and Cicero – to develop this concept as a new approach to the problem of lying and the interpretation of the eighth commandment of the Decalogue, “you shall not bear false witness against your neighbor.” Part Two transitions from interpretation of Aquinas to constructive engagement with contemporary ethics and moral theology. I develop and expand upon Aquinas’s account of truthfulness in a way that accounts for the complexities of our contemporary context, and I conclude that preserving the virtue of truth means nothing less than preserving our own humanity.


Attribute NameValues
Author Stewart Clem
Contributor Celia Deane-Drummond, Committee Member
Contributor John O'Callaghan, Committee Member
Contributor Gerald McKenny, Committee Member
Contributor Jean Porter, Research Director
Degree Level Doctoral Dissertation
Degree Discipline Theology
Degree Name PhD
Banner Code

Defense Date
  • 2018-11-13

Submission Date 2018-11-25
  • Ethics

  • Virtue Ethics

  • Moral Theology

  • Theology

  • Lying

  • Truth

  • Christian Ethics

  • Thomas Aquinas

  • Moral Philosophy

Record Visibility Public
Content License
  • All rights reserved

Departments and Units
Catalog Record


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