Here's a sentence from the Catholic Mass:

Agnus Dei,
qui tollis peccata mundi,
miserere nobis.

Why not agne? Shouldn't agnus be in the vocative? Note tollis and miserere in the second person.


Sanctus, sanctus, sanctus Dominus Deus Sabaoth,
pleni sunt coeli et terra gloria tua.

Why not Sancte, sancte, sancte Domine Deus Sabaoth? Note tua.

Earlier, in the Gloria, it says:

Domine Deus, Rex coelestis,
Deus Pater omnipotens,
Domine Fili unigenite Jesu Christe,
Domine Deus, Agnus Dei,
Filius Patris.

So, there are definitely vocatives in the Mass—five in a row in the third line. But notice Agnus and Filius in apposition with Domine—in apposition with Fili, even!

Is it time to send out an errata sheet for all those missals?

  • 1
    Good question! Regarding the Sanctus the liturgic prayer is a mosaic of quotes from different sources in the Scripture, not intended to form a grammatical unit. Note that the following verses Hosanna in excelsis/benedictus qui venit in nomine Domini, don't match either. There is an est implied: the Lord, God Sabaoth (of the armies) is three times Saint. As for the agnus Dei, I'm certain there must be a good reason: the texts come from a time when Latin was still alive! Just an idea (incomplete if at all true): perhaps it is seen as a title, since John the Baptist called him that. – Rafael Jul 26 '17 at 13:22
  • 4
    Interesting to note is that the Greek text has the same vacillation between nominative and vocative: "Κύριε ὁ Θεός, ὁ ἀμνὸς τοῦ Θεοῦ, ὁ Υἱός τοῦ Πατρός, ὁ αἴρων τὴν ἁμαρτίαν τοῦ κόσμου, ἐλέησον ἡμᾶς." This is especially noteworthy since the nominative was just used for "son": "Κύριε Υἱὲ μονογενές." Latin too, switches from "fili" first to "filius" afterwards... – brianpck Jul 26 '17 at 16:21
  • 1
    @Rafael Regarding the edit, I appreciate the thought, but the last line is a joke at my own expense: of course it's absurd to think that a grammatical error like this could have persisted for well over a millenium, in text written by native speakers. – Ben Kovitz Jul 26 '17 at 17:39
  • 1
    @hexadecimal the Lamb of God is Jesus. But the sacramental bread (after consecration) is Jesus too. See my edit. – Rafael Jul 26 '17 at 18:06
  • 1
    @Rafael Ok mainly refers to Jesus, because in the original sacrifices of lambs ... sacrifice of Jesus ... sacramental bread. Okay. I said it because this words of the question seem to me to be said when blessing the bread. Anyway, I do not see anything irregular or that requires explanation in those words beyond clarifying the functions of the vocative that does not have to be used obligatorily in those words or in the second part of the question. – hexadecimal Jul 26 '17 at 18:50

I found the question very interesting, and got me researching against my will.

Most of the texts of the Mass —and specifically these— come from antiquity, a time when Latin was still alive. Had there been grammatical errors, twenty centuries would suffice to find and correct them. So it may be a little far-fetched to put a mistake as the default hypothesis.

The examples you cite seem to have two different explanations:

  1. The Agnus Dei is somehow controversial, not in that it is a mistake, but I've found a number of educated guesses that may be seen as complementary or even contradictory. This forum gathers a few of them. Anyway, it has been accepted in liturgy as it is. Maybe this is a good question for [Christianity.SE]! Some of the explanations are:

    1. Agnus Dei as a whole is seen as a title or as a compound not to be declinable. Being a title makes a lot of theological sense, FTR. [Edit: title attributed to Jesus, just as the previous vocatives are directed toward Him. John the Baptists first called Him so, as he was to be the matter of a sacrifice —just as lambs were— to God]
    2. Agnus would be an accepted irregular vocative of agnus in Ecclesiastical Latin. (Comparable to the number IIII in clocks? This doesn't convince me a lot, but I cite it since it is sourced.)
    3. It is a nominative. (I find this one very interesting.) Quoting a participant in the forum:

      Specifically, it's a nominative used in apposition with the understood subject of the imperative miserere. Although the vocative is more common, it's not unclassical to have the nominative instead, as in Livy (i.24): audi tu, populus Albanus ("hear thou, people of Alba"). See Allen and Greenough 340a.

  2. The Sanctus is a mosaic from three different sources (two of them from both the Old and New Testament,) not intended to form a grammatical unit.

    Sanctus, Sanctus, Sanctus, Dominus Deus Sabaoth. (Is 6,3)
    Pleni sunt caeli et terra gloria tua. (a different source)
    Hosanna in excelsis. Benedictus qui venit in nomine Domini. Hosanna in excelsis. (Mc 11, 9-10)

    Translations use third person in the first and last pieces, and second person for the middle one, (although it is very common for people to mistakenly change it to third person, trying to form a unit artificially, because it just sounds better!)

  3. The Gloria is also a mosaic in the sense that the two initial verses are a quote from the Gospel of St. Luke. As for the nominatives you cite, they can find a similar explanation to 1. I don't think they can be seen as copulative predicates, since there is a predicate to this sentence —miserere nobis—. The whole sentence being:

    Domine Fili unigenite, Jesu Christe, Domine Deus, Agnus Dei, Filius Patris, qui tollis peccata mundi, miserere nobis; qui tollis peccata mundi, suscipe deprecationem nostram.

Update: as noted in this outstanding answer by Kingshorsey, an explanation to Agnus Dei —at least in the Gloria— could come from Deus. In his words, there is no (textually secure) attested vocative form of deus. (...) When a vocative became necessary for Christian Latin, they employed the nominative form (...). This was considered a nominative used in place of a vocative, not as a vocative form. Thus, the adjective meus was used for agreement. Note that in the Gloria, Deus breaks the chain of vocatives, and nominatives follow. One could imagine (though it would need to be proven) that this led to a more permanent change in the way of syntactically treating Agnus Dei when referred to Deus Filius (i.e., Jesus).

  • 2
    I support the "nominative used as a vocative" view. I think "Agne Dei" would have sounded a bit strange since, unlike "Domine", people are not accustomed to addressing lambs. (The same applies to the Greek.) – varro Jul 26 '17 at 21:29
  • 1
    @varro: I'm not sure people would have any trouble using the vocative for lambs since it's well documented that it was standard practice to use it for mice ;-) – psmears Jul 26 '17 at 21:46
  • @psmears: point taken :) – varro Jul 26 '17 at 21:54
  • 1
    @chrylis:addendum: looking on the whole phrase quoted above, Domine Fili unigenite, Jesu Christe, Domine Deus, Agnus Dei, Filius Patris, ..., I think the juxtaposition of Agnus Dei with Filius Patris was the deciding factor on the preference for Filius Patris over Fili Patris. – varro Jul 27 '17 at 0:04
  • 1
    The nominative in apposition is supported by the Greek equivalent which @brianpck cited above. – Nick Nicholas Jul 1 '18 at 10:54

Jungmann in his magisterial work on the Roman Mass suggests that this is in keeping with a grammatical rule in many languages: from a feeling of reverence, religious terms are apt to be handled as indeclinable.In a footnote he notes the vocative "Deus" (Mass of the Roman Rite, vol. 2 pg. 338).


I can't help but wonder whether there is an assumed "es" ("you are") in these phrases. Finite forms of "esse" are often severely abbreviated or even omitted in Latin.

"[You are] the holy, holy, holy Lord, God Sabaoth", etc.

  • This is a good idea, but it's already mentioned briefly in Rafael's answer (as the third possibility). Mind adding a bit more elaboration on this to make your answer distinct? – Draconis Jul 1 '18 at 3:22
  • I think you are right. Apparently, I did not understand Rafael's third possibility when I first read it. Now that I see what he's getting at, I have to say that that explanation strikes me as most probable. – Figulus Jul 1 '18 at 5:53
  • 1
    What if it was an implicit qui es instead of a mere es? I'm not sure if it's likely at all, but this reading does make many such instances more grammatical. – Joonas Ilmavirta Jul 1 '18 at 7:05
  • 1
    @JoonasIlmavirta. This is what I also think. The vocative Domine or Fili Dei to call the deity, then, the nominative in the list of sentences: (qui es) filius Dei; (qui es) Agnus Dei; qui tollis peccata mundi &c. – Pietro Majer Jan 10 at 23:47

"Agnus Dei" is wrong. Period. It is totally out of question that the vocative would be required here. This part of the liturgy is from the 7th century when Latin, at least in its classical form, was not a spoken language anymore. The use of nominative instead of vocative is a typical error of non-native Latin speakers. But apparently it has become Catholic tradition and so this grammatical error has perpetuated itself. The Vulgata has a tendency to make nouns, especially names, indeclinable. In classical Latin foreign words, especially Greek ones, were always made declinable, sometimes by adding a Latin ending. "Agnus" however is not even a foreign loanword, but a normal Latin word of the o-declension. There is no justification at all, not to decline it properly. However we know that in modern Romance languages and therefore probably in vulgar Latin of the early Middle Ages declension of nouns came out of fashion. This explains the sloppiness of the author of "Agnus Dei".

  • 4
    The text of the Agnus Dei is a literal reference to the text of the Gloria, which was written in Greek in the 3rd century. I don't think it's charitable or correct to dismiss it as a silly declension error. – brianpck Jan 6 at 23:33

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.