During his second stint as regent master of theology at the University of Paris in 1269-1272, Thomas Aquinas fulfilled the threefold magisterial task: legere, disputare, praedicare – to lecture, to dispute, to preach. On Virtues in General and On the Cardinal Virtues are two series of disputed questions which date from this period. In them Thomas, at the height of his powers and under the pressure of the raging dispute over Aristotle, discusses the central feature of his moral doctrine, virtue. During the same period he was composing his commentary on Aristotle’s Nicomachean Ethics and completing the moral part of the Summa Theologiae.These disputed questions are the work of a theologian for whom philosophy was the necessary prerequisite of his discipline. Thomas discusses virtue with reference to the definitions of St. Augustine and Aristotle and develops a distinction between the acquired virtues and the virtues which are infused into the soul by grace. The subtle interactions of the natural and supernatural have never been discussed with more clarity. Justice, prudence, courage, and temperance – the cardinal virtues – are shown to have both acquired and infused instances.