|His de causis Apostolica Sedes nullo non tempore linguam Latinam studiose asservandam curavit eamque dignam existimavit qua tamquαm magnifica caelestis doctrinae sanctissimarumque legum veste (5) uteretur ipsa in sui exercitatione magisterii, eademque uterentur sacrorum administri. Hi namque ecclesiastici viri, ubicumque sunt gentium, Romanorum sermone adhibito, quae sunt Sanctae Sedis promptius comperire possunt, atque cum ipsa et inter se expeditius habere commercium.||For these reasons the Apostolic See has always been at pains to preserve Latin, deeming it worthy of being used in the exercise of her teaching authority “as the splendid vesture of her heavenly doctrine and sacred laws.”5 She further requires her sacred ministers to use it, for by so doing they are the better able, wherever they may be, to acquaint themselves with the mind of the Holy See on any matter, and communicate the more easily with Rome and with one another.|
– Pope Saint John XXIII, in the Apostolic Constitution Veterum Sapientia, n. 4
Among the many reasons Pope St. John XXIII gives that clerics should use Latin is this: They will be better able to acquaint themselves with the mind of the Holy See. Priests exercise their ministry in communion with their Bishop and with the Holy Father, and so it is of great advantage that the clergy and the Vatican should speak the same language.
Consider a concept like ex opere operato, which has been refined and clarified over the centuries. Without a common language, the history of the theology of this term, and its treatment by various saints and theologians, would require a consideration of how individuals expressed this in their own languages in their native lands. It is very fortunate for us that Augustine, Albert and Bellarmine wrote in Latin. If we had to know twenty languages to read the saints and doctors, that would be a challenge indeed.
Moreover, if our study of theology is limited to our own vernacular, we are at the mercy of whoever furnishes the latest translation. For nearly 40 years we believed that accepit hunc praeclarum calicem in sanctas ac venerabiles manus suas translated into English as He took the cup. If the Church does not retain Latin, as St. John XXIII said she should, the future of theology will be in the hands of translators.