The fact is that despite the formal authority, the true authority is with the Sacred Tradition, against which any innovation has to be justified.
What you say here makes sense, and seems obvious to me, but that is really what confuses me about the whole thing. As an outsider (I have never seen a Mass in Latin as they were always banned by the bishop here) I just find it all very confusing. People say that the SSPX are innovative and holding to a different faith than the eternal Catholic one, and yet they are traditionalists. How can that be? If traditionalists don't hold to the "true faith" then it can only be that everybody else's definition of that has changed, and not the other way around. Or so it seems to me. And we see them being required to accept some particular interpretation of Vatican II before being allowed back into the Church, and yet at the same time Anglicans (who have made no bones about denying many councils throughout history) are being brought back in by the droves without ever being asked about particular interpretations of specific councils. Why is that? I was raised Anglican and I am fully aware of the many, many heresies and denials of the faith rampant in that church, and yet they are somehow accepted as being more catholic than the SSPX? How could that even be a little bit possible? Self professing lesbian Buddhists cannot be denied communion, but we can't allow the SSPX back in? Huh?!?
My apologies as I meant to direct the above comment to you as well in case you felt it might impact our conversation. I had done that for post 23 and intended to do the same for 24 but forgot.
I completely share your amazement, except being around this controversy for about 10 years now (since I started really paying attention, in other words), it dulled.
Of course the truth is that the Vatican II produced a number of non-doctrinal documents and introduced some liturgical changes, which, the bishops thought, was in continuity with the Tradition. Then the groups on periphery of Catholicism, both inside of it like the liberal wing of Catholicism, and outside of it, like the secular press and the Jews, took it to mean precisely the opposite, discontinuity. Things got so bad that the Traditional Mass got banned, and the elements of it meant to remain in the Novus Ordo disappeared.
In 21c, and especially, in this blessed pontificate, things began to improve. Several traditionalist ecclesial bodies were received back, like the Fraternal Society of St. Peter, SSPX got from under the excommunications, and the Latin Mass restored withing the new liturgical calendar and with restrictions.
The dialog with SSPX, -- or rather with the serious wing of it, as it has some closet sedevacantists there as well, -- went just fine from there. And now we have gotten to the crux of the matter: is Vatican II, according to the Roman Curia, a new religion that cannot be reconciled with SSPX or is it just a left liberal flavor of Catholicism in continuity with the rest of the Church here and in Heaven.
If the leaked document is to be believed, the way to see it as continuous withing the Church was presented by Bishop Fellay, and it was not rejected outright but rather re-written so that it no longer reflected the desired continuity. So therefore, at least with Levada in charge of the dialog, we have our answers: Roman Curia does not see Vatican II as continuous.
So Levada should be fired, and probably, His Holiness needs to take up the task himself, or else this generation of Catholics will know that the Catholic Church is still on her journey through the desert, unfortunately, and remains unattentive to the needs of our souls.
The SSPX rejected the Church's teaching authority (as reflected in Vatican II) while members of the Church; Anglicans rejected the Church's teaching authority while clearly outside the Church. When the latter ask to join the Church, they make a statement of change that the former do not.