36. 1. Particular law remaining in force, the use of the Latin language is to be preserved in the Latin rites.
2. But since the use of the mother tongue, whether in the Mass, the administration of the sacraments, or other parts of the liturgy, frequently may be of great advantage to the people, the limits of its employment may be extended. This will apply in the first place to the readings and directives, and to some of the prayers and chants, according to the regulations on this matter to be laid down separately in subsequent chapters.
3. These norms being observed, it is for the competent territorial ecclesiastical authority mentioned in Art. 22, 2, to decide whether, and to what extent, the vernacular language is to be used; their decrees are to be approved, that is, confirmed, by the Apostolic See. And, whenever it seems to be called for, this authority is to consult with bishops of neighboring regions which have the same language.
4. Translations from the Latin text into the mother tongue intended for use in the liturgy must be approved by the competent territorial ecclesiastical authority mentioned above.
Source link (all subsequent quotations from this Vatican II document are from this same source link).
Now, the document has many parts, and its many parts are written in different styles (or, to use the fancier word, "genres"). I submit that section 36 is written in a legal style or genre. In contrast, the first chapter of the document is written in an exhortatory style, more in keeping with the genre we all know as a sermon or homily (biblical scholars like to refer to this style as "paraclesis" from a Greek word meaning "encouragement''). We need to establish the genre of the passage we are seeking to understand before we begin quoting sentences out of context.
The structure and language of section 36 quoted above are, I submit, in a legal style or genre. This fact means that we must be very careful in understanding the structure of the passage and not just quote an isolated fragment. The structure of this typical legal passage is that of a general principle or rule followed by exceptions. It makes no sense at all to quote the general rule without considering the immediately following exceptions. In the legal genre, what is given in a general rule is often taken back in the exceptions. So, for example, it is misleading for someone to simply quote the phrase "the use of the Latin language is to be preserved in the Latin rites" in order to attack Masses which are celebrated entirely in the vernacular, without considering the immediately following exceptions. Yet, I think that in the past few decades, such quoting out of context without regard to genre has been quite frequent when this particular issue is discussed.
Take a close look at the exceptions after the general rule that the "use of the Latin language is to be preserved in the Latin rites." The exceptions make clear that, in spite of the general rule, the appropriate church authorities, with approval of the Vatican, can extend the use of the vernacular. The document then cross-references section 22. 2 to identify the competent ecclesiastical authorities that can extend the use of the vernacular: "2. In virtue of power conceded by the law, the regulation of the liturgy within certain defined limits belongs also to various kinds of competent territorial bodies of bishops legitimately established."
Section 36 also cross-references "subsequent chapters" of the document as guides in extending the vernacular in the Mass. For example, in section 54 (from Chapter 2), we read:
54. In Masses which are celebrated with the people, a suitable place may be allotted to their mother tongue. This is to apply in the first place to the readings and "the common prayer," but also, as local conditions may warrant, to those parts which pertain to the people, according to the norm laid down in Art. 36 of this Constitution.
Nevertheless steps should be taken so that the faithful may also be able to say or to sing together in Latin those parts of the Ordinary of the Mass which pertain to them.
And wherever a more extended use of the mother tongue within the Mass appears desirable, the regulation laid down in Art. 40 of this Constitution is to be observed.
[End of quotation]
As is typical of legal documents, we have cross-references to other sections. In Section 54, we see again that the extent of the use of the vernacular is not clearly demarcated or defined but is left to the competent ecclesiastical authorities. Some will quote the sentence reading "Nevertheless steps should be taken so that the faithful may also be able to say or to sing together in Latin those parts of the Ordinary of the Mass which pertain to them," as defining or limiting the extent of the use of the vernacular in the Mass. That interpretation is not clear to me at all. I read the sentence about the faithful's being able to say or sing parts of the Ordinary in Latin as indicating that, where Latin is retained in the Ordinary, the people must be able to say or sing it. It is not enough to just introduce some vernacular while leaving the people uninstructed in the parts that may remain in Latin. My interpretation coincides with the overarching theme of the document, which is to encourage full and active participation of the laity in the liturgy (see Section 11, which I quote in part, which requires pastors "to ensure that the faithful take part fully aware of what they are doing, actively engaged in the rite, and enriched by its effects."). I do not see any limit being placed here on the competent church authorities' ability to extend the vernacular to the entire Mass, but simply an emphasis on full and active participation by the people by means of instruction where Latin is used. In support of this interpretation, I direct your attention to the explicit contemplation of "a more extended use" of the vernacular in the last sentence of Section 54 quoted above.
Finally, in further confirmation of the legal genre with which we are dealing in these sections , we have another cross-reference--this time to Section 40 which contemplates "even more radical adaptation" of the liturgy "to the cultures and traditions of peoples" (for the sake of brevity, I will not quote all of Section 40; you can easily read it yourself by following the source link at the beginning of this post). (Alas, the cross-referencing reminds us of the ordeal of having to fill out our annual tax returns--tax returns and tax return instructions are also in the legal style or genre.)
In sum, the parts of Sacrosanctum Concilium dealing with the extent of the use of the vernacular in the Mass are written in a decidedly legal style or genre which requires reading the sections together and understanding that in the legal style of writing the exceptions that follow a general rule do matter greatly. Those exceptions to the initial general principle of preserving Latin have given us licit Masses entirely in the vernacular as authorized by the competent ecclesiastical authorities with the approval of the Vatican. There is thus nothing illicit at all about celebrating Mass in the Roman Rite entirely in the vernacular. Such flexibility and discretion in extending the vernacular is, in my opinion, clearly contemplated by the legal language, genre, and cross-references in the text of Sacrosanctum Concilium.
Now, you and I normally do not write that way; but, understandably, a Church council legislating for the universal Church did. It is a serious mistake to miss the difference that the legal genre makes in quoting pieces of legislation out of their legal context. Let me end with a quotation from the much more recent General Instruction of the Roman Missal (2002), which comments on the use of the vernacular in the Mass in Section 12:
Since no Catholic would now deny the lawfulness and efficacy of a sacred rite celebrated in Latin, the [Second Vatican] Council was also able to grant that “the use of the vernacular language may frequently be of great advantage to the people” [quoting Section 36 of Sacrosanctum Concilium] and gave the faculty for its use. The enthusiasm in response to this measure has been so great everywhere that it has led, under the leadership of the Bishops and the Apostolic See itself, to permission for all liturgical celebrations in which the people participate to be in the vernacular, for the sake of a better comprehension of the mystery being celebrated.
Source link (Section 12; PDF document; emphasis added).
Some will still opine that the exceptions should not swallow the initial general rule because they favor the initial general rule of preserving Latin in the Roman Rite. My response is that the exceptions granted a wide discretion, subject to Vatican approval, and did not obligate anyone to make the vernacular so extensive. The argument about the extent of the vernacular in the Mass has to take place at another level--the level of friendly persuasion as to how to best exercise the licit discretion granted by Rome, not at the level of denying the legal reality of that extensive licit discretion. No one defied the Council Fathers in extending the vernacular to the entire Mass; the discretion granted by the Council Fathers was licitly used. Personally, I favor some Latin in the ordinary parts of the renewed post-Vatican II liturgy, as done in my charismatic parish; but I am also fully comfortable attending Masses in which there is no Latin at all. We have bigger fish to fry.