III.

(Most holy father, p. 18.)

This expression leads me to think that this epistle is addressed to the Bishop of Antioch or of some other Apostolic See. It must not be taken as a prescribed formula, however, as when we say "Most Reverend" in our days; e.g., addressing the Archbishop of Canterbury. Rather, it is an expression of personal reverence. As yet, titular distinctions, such as these, were not known. In the West existing usages seem to have been introduced with the Carlovingian system of dignities, expounded by Gibbon.