The doctrinal preamble is non-negotiable. The existence of a hermeneutic of continuity, as such, is not a matter for debate.
Here is a section from the Final Report for the Synod of Bishops of 1985. It seems to be one of the first, if not the first reference to conciliar continuity, and may have been influenced by Joseph Ratzinger. It is highly unlikely, to my mind, that is was not:
The theological interpretation of the conciliar doctrine must show attention to all the documents, in themselves and in their close inter-relationship, in such a way that the integral meaning of the Council’s affirmations–often very complex–might be understood and expressed. Special attention must be paid to the four major Constitutions of the Council, which contain the interpretative key for the other Decrees and Declarations. It is not licit to separate the pastoral character from the doctrinal vigor of the documents. In the same way, it is not legitimate to separate the spirit and the letter of the Council. Moreover, the Council must be understood in continuity with the great tradition of the Church, and at the same time we must receive light from the Council’s own doctrine for today’s Church and the men of our time. The Church is one and the same throughout all the councils.
Basically, the doctrinal preamble states that “[i]t is not licit to separate the pastoral character from the doctrinal vigor of the documents. In the same way, it is not legitimate to separate the spirit and the letter of the Council.” This has been the essential point all along and Joseph Ratzinger, now the Vicar of Christ, will not budge.
I know many have a problem with this statement, but at some point those who love the Church will have to concede to Peter. This brings to mind the response of Cardinal Ottaviani to the new Mass and his eventual acceptance of the liturgical changes. [see comment below The following quote was made by Cardinal Ottaviani before the intervention. The comment linked to shows other evidence of his acceptance of the liturgical changes, though this one indicates his disposition of obedience]:
The words of Christ “feed my sheep” are words which have been addressed only to His Vicar, and it follows that whoever would wish to be counted among the Flock of Christ must submit to the Universal Pastor appointed by Christ. No one can be an exception to this rule, not even bishops.
There is no way around this point except to fall into sectarianism.
I find this report concerning Bishop Fellay’s reaction to the decision of the CDF interesting:
During this morning’s meeting, however, he appeared more conciliatory, and in a private conversation that took place in the palace of the former Holy Office, he said he had “no difficulty in accepting the profession of faith,” and also claimed to have no difficulties with the principles expressed in the preamble: the problem, Fellay said, was not the principles, but their application – namely, the fact that the Church today lacks fidelity to the Magisterium.
But this not what he was saying six weeks ago, when it was clear that he would not sign and he was giving his reasons why:
And I may say, what is presented today, which is already different from what was presented on the 14th of September, we can consider it as all right, good. They fulfilled all our requirements, I may say, on the practical level. So there is not much problem there. The problem remains at the other level – at the level of the doctrine. But even there it goes very far – very far, my dear brethren. The key is a principle. Which they say, “this you must accept; you must accept that for the points that make difficulty in the Council – points which are ambiguous, where there is a fight – these points, like ecumenism, like religious liberty, these points must be understood in coherence with the perpetual teaching of the Church.” “So if there is something ambiguous in the Council, you must understand it as the Church has always taught throughout the ages.”
This is problematic to say the least. Heads up and pray for Bishop Fellay and the members of the SSPX. This is their last chance.