This dissertation is a study of Thomas Aquinas’s (1225–1274) and Godfrey of Fontaines’s (d. 1306) moral philosophies. In this study, I conduct a detailed analysis of two Aristotelian commitments concerning the character virtues, namely, The Plurality of the Character Virtues and The Connection of the Character Virtues. Both Aquinas and Godfrey think that there are many distinct character virtues (such as moderation and justice), however, one cannot (perfectly) possess these character virtues in separation from each other. In Chapter I, it is established that Aquinas believes in the plurality of the character virtues not because of a specific account of the human soul, but because he is committed to a plurality in what he calls “the notion o...