Cajetan (Tommaso de Vio), the most influential Renaissance Thomist, studied and taught in Italy, early distinguishing himself in teaching, commentaries, and debates as a philosopher and theologian. Rising to the leadership of the Dominican Order and becoming prominent in ecclesiastical politics, he was made cardinal in 1517. In 1518–1519 he disputed with Martin Luther.

Cajetan's works number more than a hundred titles. His later writing was primarily devoted to biblical exegesis; his primary contributions to Thomistic philosophy and theology are due to his earlier commentaries and treatises, most notably his commentary on St. Thomas Aquinas's De Ente et Essentia (On being and essence, 1495), his treatise De Nominum Analogia (On the analogy of names, 1498), and his formidable commentary on Aquinas's Summa Theologiae (1507–1522), which is printed with the pontifical (Leonine) edition of Aquinas's work. Other significant philosophical works include commentaries on Porphyry's Isagoge and on Aristotle's Categories, Posterior...