Aquinas's Synthesis of Aristotelian and Theological Virtue

Thomas Aquinas (1225-1274) undertook, chiefly in the Prima Secundae and Secunda Secundae of his Summa Theologiae (composed in stages between roughly 1265 and 1274, left unfinished at his death), a systematic integration of Aristotle's Nicomachean Ethics — newly available to Latin readers through William of Moerbeke's fresh translation from the Greek, completed around 1246-1247, which superseded earlier partial and less reliable versions — with the moral and theological framework of Christian doctrine. Aquinas preserves Aristotle's core apparatus largely intact: virtue as a stable habitus (the Latin rendering of hexis) perfecting a human power, the doctrine of the mean, and the indispensable role of prudentia, practical wisdom, in applying general moral knowledge to particular circumstances. To this Aristotelian foundation of the four cardinal virtues — prudence, justice, fortitude, and temperance, attainable by natural human reason and habituation — Aquinas adds a second, higher tier of theological virtues: faith, hope, and charity, drawn from Paul's First Letter to the Corinthians 13:13 ("So faith, hope, and charity remain, these three; but the greatest of these is charity").