In official language papal documents have at all times been called by various names, more or less descriptive of their character. For example, there are “constitutions,” i.e., decisions addressed to all the faithful and determining some matter of faith or discipline; “encyclicals,” which are letters sent to all the bishops of
Christendom, or at least to all those in one particular country, and intended to guide them in their relations with their flocks; “decrees,” pronouncements on points affecting the general welfare of the Church; “decretals” (
epistolae decretales), which are papal replies to some particular difficulty submitted to the
Holy See, but having the force of precedents to rule on all analogous cases. “Rescript,” again, is a form applicable to almost any form of Apostolic letter which has been elicited by some previous appeal, while the nature of a “privilege” speaks for itself. But all these, down to the fifteenth century, seem to have been expedited by the papal chancery in the shape of bulls authenticated with leaden seals, and it is common enough to apply the term
bull even to those very early papal letters of which we know little more than the substance, independently of the forms under which they were issued.
