"...in matters of faith even the statement of one single private person can take precedence over statements by the Pope, whenever he (the private person) is guided by better reasons and authoritative grounds in the Old and New Testaments than the Pope is." (Nicholas de Tudeschis (Panormitanus), d. 1445).
Luther: Hearken, ye papists! Paul curses an angel from heaven if he teaches differently from the Scriptures, and I am not to have the power to despise a man if he teaches differently! Why do ye not also condemn that chapter of Panormitanus, Significasti, de Electione, which I have cited, in which he says that we are to believe a layman, if he presents plain Scripture or clear reason, rather than a pope or a council; and this opinion is shared by almost all the jurists, especially the ablest and most learned among them.