Cajetan, Jacopo (Tommaso de Vio) (1469–1534)

Italian Dominican theologian. A committed opponent of the Reformation, he played an active role in the international politics of his age, being involved in the elections of Emperor Charles V and Pope Adrian VI. He also disputed with Martin Luther and strongly opposed the divorce of Henry VIII from Catherine of Aragon.

He entered the Dominican Order in 1484 and studied at Naples, Padua, and Ferrara. He taught philosophy and theology at Brescia, Pavia, Paris, and Rome. He was general of the Dominican Order 1508–18, and spoke in favour of reform of the church at the Fifth Lateran Council of 1512–17. He was appointed a cardinal in 1517 and in 1518 bishop of Gaeta (Caieta, hence his name). In 1517 Pope Leo X sent him as papal legate to Germany, where he was to urge Emperor Maximilian and the Scandinavian kings to form a league against the Ottoman Turks. He was also to bring Luther back into the Church, and in 1518 argued the Church's case with Luther in Wittenberg. In 1523 he was appointed papal legate to Hungary. He was a prolific writer, and from 1507–22 published a commentary on the Summa theologica of St Thomas Aquinas that remains an important contribution to Thomist philosophy.