In Veterum sapientia, Pope John XXIII had insisted that the Latin language must remain central to the culture of Western Christianity. That Letter is not primarily about the language of worship; it desires Latin to remain a living vernacular for the clergy and not least for their formation; and it is based upon the belief that, by being latinate, a clerisy will have access to a continuity of culture. As C S Lewis's Devil Screwtape confessed, "Since we cannot deceive the whole human race all the time, it is most important thus to cut every generation off from all others; for where learning makes a free commerce between the ages there is always the danger that the characteristic errors of one may be corrected by the characteristic truths of another". Both in secular culture and within the Church, there is a risk that the educated class will be cut off and imprisoned in the narrow confines of a particular culture - victims of its particular Zeitgeist. A literate clerisy is one that reads what other ages wrote, which means that it will at least be able to read Latin; and the sign of such a clerisy, in practical terms, will be that it can with ease read its Divine Office in Latin.
It is in this context that we must see the requirement of Vatican II: "In accordance with the centuries-old tradition of the Latin rite, the Latin language is to be retained by clerics in reciting the Divine Office". And it is highly significant that it goes on to make the use of the vernacular an exception which bishops can grant only on an individual basis. One might plausibly surmise that this permission may have been envisaged as useful in areas where resources for clerical formation were limited. I wonder how the Council Fathers - or a sizeable proportion of them - might have reacted to the information that in less than a decade the bishops of Western Old Europe (whose culture both religious and secular had been based upon Latin for nearly two millennia, the continent of the great universities in which the civilisation of the Greek and Roman worlds had been transmitted) would have discerned that "the use of Latin constitute[d] a grave obstacle to their [most of their clergy] praying the Office properly".
Readers of this blog are probably familiar with the other prescriptions of Vatican II for the retention of Latin, and I will not labour the point. I emphasise that I am not basing an argument for the retention of a living Latin culture upon the words of the Council. The auctoritas for that retention is very much more broadly based. The concilar mandate is merely the icing on the cake; the guarantee that in an age of revolutions the old securities are still in place. Without these words of the Council, it might have been plausibly argued that a radical cultural and intellectual shift had invalidated the previous assumptions. In view of the explicit orders of the Council, such a thesis can only be advanced as a deliberate repudiation of the explicit words of the Council ... as well as of the centuries preceding it. And yet there are those who do advance it ... and even have the gall to claim to be the Guardians of the Spirit of the Council. I have read a self-righteous demand that SSPX should not be canonically regularised unless it submits to "everything the Council said".
I put this question of Latin before you as an example of what auctoritas means. I know that in the post-Conciliar period miserable little legislative documents sneaked out of Roman dikasteries and episcopal conferences claiming to nullify the explicit conciliar mandates for the retention of Latin both in worship and in the intellectual culture of the Church. For all I know, there may even be some such legislative basis for ignoring the requirement in the 1983 Code that seminarians should be fluent (bene calleant) in that tongue. With debitum obseqium I suggest that such enactments, since they directly contradict the words of a pontiff as recent as John XXIII and the mandates of a very recent Ecumenical Council (as well as the entire paradosis of Latin Christendom), are totally lacking in auctoritas and should be shunned and despised (particularly by those to whom 'The Council' means so much) ... and reversed by the relevant legislators.
They are, of course, also totally canonically valid, as long as they persist.