Liberius is the second most notorious “pope”, whose adoption of heresy Rome had to deal with while trying to wriggle out some form of “infallibility” (following Honorius, 625-638).
This question came in an email: “I wonder if you might point me to some scholarly materials on pope Liberius. I know that it is standard Protestant apologetic to argue against the papacy by pointing out that this pope succumbed to Arian pressure. Of course the standard Catholic reply is that those materials are forgeries. If you have some time would you mind recommending some sources?”
Johnann Joseph Ignaz von Dollinger, who was a Roman Catholic historian prior to Vatican I (and who argued strenuously against “Infallibility”), described it this way:
