Aquinas on Virtue: A Causal Reading is an original interpretation of one of the most compelling accounts of virtue in the Western tradition, that of the great theologian and philosopher Thomas Aquinas (1224-1274). Taking as its starting point Aquinas's neglected definition of virtue in terms of its "causes," this book offers a systematic analysis of Aquinas on the nature, genesis, and role of virtue in human life. Drawing on connections and contrasts between Aquinas and contemporary treatments of virtue, Austin argues that Aquinas's causal virtue theory retains its normative power today. As well as providing a synoptic account of Aquinas on virtue, the book includes an extended treatment of the cardinal virtue of temperance, an argument for the superiority of Aquinas's concept of "habit" over modern psychological accounts, and a rethinking of the relation between grace and virtue. With an approach that is distinctively theological yet strongly conversant with philosophy, this study will offer specialists a bold new interpretation of Aquinas's virtue theory while giving students a systematic introduction with suggested readings from his Summa Theologiae and On the Virtues.