So were the Jansenists. But they were still mistaken. Believe me, I can understand loathing much of what Pope Francis does---most of what he does, in fact--- but we can't jump off the ark and abandon the seat of the Papacy, no matter who occupies it. It's a sad day when you have to pray for the Pope's conversion, but Catholics must respect his office, if not the man. That is where sedevacantists make their error. He could be a terrible Pope, but until he dies or abdicates he's still the Pope. Ours is the sort of difficult era that produces the greatest villains and the most heroic saints.
So were the Jansenists.
Actually the Jansenists were not Catholic. While some viewed them as just puritanical, they separated themselves from the Church by their schism, heresy and attack on the liturgy.
This, May 10th, being the Feast of Saint Antoninus I thought I would include his declaration of Church teaching if a pope were ever to become a heretic AFTER a valid election.
St Antoninus (1459)
"In the case in which the pope would become a heretic, he would find himself, by that fact alone and without any other sentence, separated from the Church. A head separated from a body cannot, as long as it remains separated, be head of the same body from which it was cut off. A pope who would be separated from the Church by heresy, therefore, would by that very fact cease to be head of the Church. He could not be a heretic and remain pope, because since he is outside of the Church, he cannot possess the keys of the Church."
Summa Theologica, cited in Actes de Vatican I. V. Frond, publisher.
It's a sad day when Catholics believe a non-Catholic/manifest, public heretic who teaches the universal church heresy can remain/become the head of the Catholic Church. And to believe that sedevacantists don't respect the office of the papacy or have somehow gone off the deep end is the error that most non-sedevacantist Catholics make when judging sedevacantism and Catholics who are sedevacantist.