I’m not arguing that Vatican II didn’t promote doctrinal error. I agree that it did—particularly on religious liberty, ecuмenism, and the re-framing of non-Christian religions.
The question is whether those errors ever became the faith of the Church as believed and lived.
In the Eastern Catholic Churches, doctrine is not primarily received through conciliar texts or episcopal policy statements. It is received through worship. Lex orandi, lex credendi is not a slogan in the East; it is the governing principle of theology.
And here is the key point: none of the contested Vatican II errors were ever prayed into the Eastern rites.
There is no liturgical affirmation of religious liberty as a natural right to error.
There is no ecuмenical liturgy that treats false religions as salvific paths.
There is no redefinition of the Church’s uniqueness or Christ’s exclusive mediation.
What the East prays today is what it prayed before the Council.
That matters because in Eastern theology, what is not prayed is not believed—no matter what appears in docuмents. The Council’s errors remained textual, not ecclesial, in the East.
This is also why the Filioque is relevant. The East never accepted a doctrinal formula simply because it was promulgated juridically. They resisted it precisely because it altered the Church’s prayer and therefore the Church’s belief. Rome eventually conceded that the Creed could be professed without the Filioque, implicitly admitting that worship governs doctrine, not the other way around.
So the argument is not “Vatican II was harmless.”
It’s that its errors never became Catholic belief where lex orandi was preserved.
The Byzantine rite accepts the Filioque, the same as pre-V2 Western Catholicism, right? In other words, the Byzantine is not orthodox, right?
Which means the Church never lost the Faith as such.
And if the Faith was never lost everywhere, then a permanent “state of necessity” cannot be sustained.
Yes and no. Yes, I agree with your analysis that a handful of non-orthodox, eastern rites were not corrupted by V2. No, I disagree that the Trads "state of necessity" in the West thereby goes away. Because a catholic cannot simply switch rites (i.e. from latin to eastern) as he wants. That's not the purpose of the rites, to be switched back and forth. Also, I don't think God would want all of the West to simply abandon the latin rite and go eastern. Thus, the "state of necessity" still exists...for the latin church.
That doesn’t refute the SSPX critique of the Council.
It refutes the claim that the Church as a whole entered doctrinal extinction.
I don't know if anyone ever claimed that the Church "as a whole" was doctrinally extinct or corrupt.
Arguably, if the pope says the V2 rites are ok, then even the Byzantine rite would have to implicitly accept this, because they are under the pope. Practically, it wouldn't change what they do, but this is still a corruption.
Regardless, when latin rite people say the "church is corrupted" they typically mean their rite. Honestly, I have no idea about the Byzantine rites (or any other legit eastern rites) and couldn't tell you much about them at all. I just know that the latin rite is in chaos and thus, for us, there is a state of necessity.