On papal infallibility pre-Vatican I

V. … Now such a judge can be found nowhere else than in the church where they erect four tribunals from which there is no appeal: (1) the church; (2) the councils; (3) the fathers; (4) the pope. But when the votes are properly counted, the pope remains solus (alone), to whom they are accustomed to ascribing that supreme and infallible judgment.

VI. That such is this opinion this passage from Andradius (who was in the Council of Trent) proves: “This high authority of interpreting the Scriptures we grant not to individual bishops, but to the Roman pontiff alone, who is the head of the church, or to all the chief offices collected together by his command” (Defen. triden. fidei, lib. 2+). “That judge cannot be the Scriptures, but the ecclesiastical prince; either alone or with the counsel and consent of the fellow bishops” (Bellarmine, VD 3.9*, p. 110). “The Roman pontiff is the one in whom this authority, which the church has of judging concerning all controversies of faith, resides” (Gregory of Valentia, Analysis fidei catholicae 7 [1585], p. 216). Still this is not the opinion of all. For although they who exalt the pope above the council ascribe this authority of a judge to him, yet they think differently who hold the council to be above the pope finally. Others, to reconcile these two opinions, think the pope (in the council) or the council (approved by the pope) is that infallible judge.

[Turretin, Institutes, 2.XX.5-6]