Duplicate naming of Vatican documents


When looking up Christus Dominus, I found that there is a 1953 apostolic constitution by Pius XII by that name, as well as a decree by the Second Vatican Council promulgated by Paul VI.

[list=1]*]Are there any guidelines on referring to such documents, to make clear which document is being cited?

*]Does the Vatican make any effort to keep from issuing documents with conflicting titles? Considering the somewhat limited range of topics that are issued, it is not surprising that two documents would begin with the same words.

*]Are there other documents with identical titles?[/list]


Neither is exactly titled that way. The designations come from the first words in Latin. For example, the Vatican II document starts

CHRISTUS DOMINUS, Filius Dei vivi …

while the Apostolic Constitution of Pius XII begins

Christus Dominus, «in qua nocte tradebatur» …

One has to make the differentiation by author, document type, and date.

Anyway, it’s all quite normal. For example, Summorum Pontificum begins with those exact words.


It seems they get named from a particular Latin phrase in the document, but they are usually a different type of document, author, and year.

For your example: Apostolic Constitution (Pius XII, 1953) or Conciliar Decree (Paul VI, 1965).



Specifically, they get named from the first phrase in the document (called the incipit). This is very standard. It is also why, for instance, the Tantum Ergo is called Tantum Ergo (“So great, therefore,”).


I was shocked to read this, and went immediately to the linked document to see if Summorum Pontificum also began with “Christus Dominus”…

[quote=MarkThompsan]Specifically, they get named from the first phrase in the document (called the incipit)

Exactly how is the incipit defined? My understanding was always that it was the first two words, but then Deus Caritas Est came out. How common are three-word incipits, and are there any four- or one-word incipits?

[Edit]I should have looked at Vico’s link in post #3 first, which gives an extensive list of titles, including many 3-word, as well as a few 4- and 1-word incipits. I’m still curious about how an incipit is defined, and who does so.


Provida Mater Ecclesia is both a 1936 instruction and a 1947 apostolic constitution.


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