If a thing be not true, it is not to be accepted as true, no matter who says it But when the Pope defines infallibly, he cannot say what is not true, and Catholics accept his official teaching precisely because it is infallibly true. If, prior to a definition, a Catholic was of a diverse opinion, then once the Pope has given the definition, such a Catholic becomes aware that his conjecture was erroneous, and abandons it in order to have the truth.
Radio Replies Volume 1 by Rev. Dr. Leslie Rumble MSC and Rev. Charles Mortimer Carty