I've been repeatedly accused of just "making up" some notion that the Church's Magisterium is indefectible, but we clearly see Pope Pius IX teaching it here. Without an a priori dogmatic understanding that the teaching of the entire Church (meaning all the world's bishops teaching in union with the Pope) cannot err, the dogma of papal infallibility has nothing to stand on, and the Old Catholics MAY have been right. But, since Etsi Multa wasn't infallible, maybe he was wrong about that too, no?
So, we say that we have dogmatic certainty about solemn papal definitions because of the dogma of papal infallibility. But what about BEFORE infallibility was defined? Did Catholics before Vatican I have no dogmatic certainty about authoritative papal teaching? In fact, how can we be dogmatically (absolutely) certain that papal infallibility is true unless we're ALREADY dogmatically certain that the entire Church (Pope and Bishops) cannot err in teaching the entire Church? Answer is that without such an understanding of the indefectibility of the Church's Magisterium, we can't be, and it's not dogmatically certain that the Old Catholics were wrong. Heck, if an Ecuмenical Council could go off the rails as it did at Vatican II, what says Vatican II didn't already go off the rails before it?
There's really only two ways out of it, R&R:
1) Either accept that Vatican II was essentially Catholics (perhaps abused, misinterpreted, with some ambiguities that need to be properly resolved by the Church's authority.
2) Or two, assert that the teachings of Vatican II were not those of the Pope and the Bishops teaching in union with him, which would mean that Montini was not the Pope.
There's simply no other way to resolve this problem in a Catholic manner, except in one of the two answers above.
There is no problem here to resolve, Ladislaus, except an imaginary one on your part.
Stop and look at what Pope Pius IX is saying, but let us change your emphasis:
they boldly affirm that the Roman Pontiff and all the bishops, the priests and the people conjoined with him in the unity of faith and communion fell into heresy when they approved and professed the definitions of the Ecuмenical Vatican Council. Therefore they deny also the indefectibility of the Church and blasphemously declare that it has perished throughout the world and that its visible Head and the bishops have erred (your quote)
This entire quote relates to the Old Catholics rejecting the
infallible teaching on infallibility and the definitions of the Council which enjoy that same
infallibility.
Pope Pius IX is not saying the Old Catholics deny the indefectibility of the Church because they refused novelties of the Ordinary Magisterium, but because they refused infallible teaching. The same Pope made very clear what was infallible.
The Second Vatican Council was clearly not a Council like the First Vatican Council and even styled itself as a Pastoral Council, refusing to define dogma.
The Pope is never infallible unless he wants to be, that is obvious. That is why Archbishop Lefebvre told you, in line with Church teaching, that it is necessary to examine to what extent the Pope intended to engage his infallibility. So it is with the Ordinary Magisterium. It is not in and of itself infallible, as were the definitions of Vatican I.
So in response to your post above:
1. The novelties of Vatican II were not 'essentially Catholic', and
2. These novelties of Vatican II were not infallibly promulgated by the Pope and the Church and are not part of Catholic teaching, which by no Catholic logic at all results in the deposition of the Pope who promoted such errors.