 Vitoria’s health became precarious in the 1540s, and the dominant role at Salamanca passed to his disciples. The most important of these was Domingo de Soto, who was born in Segovia 1494 of humble origins, studied in Alcalá and Paris, entered the Dominican order before he was thirty and was appointed to the second chair of theology, the Catedra de visperas, at the University of Salamanca in 1532. Later he became the prior of the Convent of San Esteban in Salamanca and was from 1548–1550 confessor to Charles V. After this, he returned to the university, where he held the first chair of theology. He died at San Esteban in 1560. Together with Melchior Cano, another important disciple of Vitoria, who later became bishop of the Canary Islands, he participated in the Council of Trent (1545–1563) by order of Spain’s privy council. Soto, although without a vote in the council, urged bishops to attend to the work of preaching; and he defended Scholastic theology against proposals to suppress it. Before returning to Spain, Soto helped with the preparations for Charles V’s Augsburg Interim (1548), which made concessions to the Protestants. One result of Soto’s presence at Trent was his tract De natura et gratia, which focused on the errors of Martin Luther, whose writings he called “diabolic” (Soto-DII VII, qu. 5 ad. 4; Grimm 2017: 64). In addition, he wrote an Apologia against a fellow Dominican, Ambrosius Catharinus Politus, concerning the certitude of grace.