Silvestro Mazzolini was born at Priero in Piedmont, from which he took the name Prierias, and entered the Dominican order as a youth. A prolific scholastic author, he became Master of the Sacred Palace in 1515, the pope’s own theologian and the censor of books in Rome. He was the first man in Italy to examine Luther’s theses, and in 1518 he published the first Roman answer, a Dialogue dedicated to Leo X.¹

The book opened with four “foundations” on the authority of the church, and the third of them laid bare the issue that would divide Christendom:

Whoever rests not in the doctrine of the Roman Church, and the Roman pontiff, as the infallible rule of faith, from which the Holy Scripture itself derives its force and authority, is a heretic.¹ Sylvester PrieriasDialogue against Luther’s Theses, 1518

The rest of the Dialogue mixed argument with ridicule. Prierias wondered whether this Martin had “a nose of iron, or a head of brass,” and suggested that a bishopric would soon change his views on indulgences. Luther replied within days, setting Scripture against the papal claim. Prierias also served among the judges who summoned Luther to Rome in 1518, and wrote twice more against him before his death in 1527.

His importance lies in his candor. Before Eck or Trent, the pope’s theologian had said plainly that the authority of Scripture depends on the Roman pontiff. The Reformation answered that the church stands under the Word, not over it.

Catholic Opponents