Abstract

In After Virtue, MacIntyre claims that modern thought inherited the fragments of moral philosophy from the ancient and medieval worlds, but not the conception of reason that once held these fragments together in a coherent, teleological picture of humanity. A new, limited conception of reason, ushered in by Protestantism and Jansenist Catholicism, restricted reasoning to truths of fact and mathematical relations, undermining reason's ability to "comprehend essences or transitions from potentiality to act," thus undermining moral philosophy's ability to fulfill its inherited goals. This dissertation extends this critical thesis to the whole of seventeenth and eighteenth century philosophy, emphasizing two points: the adoption of Martin Luther's doctrine of total depravity in the development of this new conception of reason, and the consequent loss of a pre-Reformation conception of humanity wherein language functioned as the guarantor of the rational correspondence of mind and world and thus of the coherence of philosophy