The jurisdiction of the Roman see is, and always has been, a point of controversy, not merely between the adherents of that see and all other Christians, but even among those who look with reverence akin to devotion to the successor of St. Peter. It is not merely a legal question, it is essentially a theological question, and as a doctrine it must be dejure divino. Accordingly, it has been discussed with that acrimony which as from a psychological necessity is characteristic of so many theological disputes. But discussion of the development of the doctrine and practice does not necessarily involve polemics. For a doctrine may be true or false, and to show this is a matter of exegesis and systematic theology, but to show that as finally stated it was the result of a long development is not to touch upon the question of its truth at all. Thus one may ask as to a doctrine closely connected with that we are to discuss, does the teaching of the Church as stated in the Bull, Unam Sanctam, appear in the second or third century as an article of belief required to be held by all Christians as a condition for receiving the sacraments? To show that it does not so appear, is merely to show what nearly every one acknowledges as to almost any doctrine not involved in modern polemics, that in the earliest ages they were not formulated with any great precision, in fact were expressed in forms sometimes afterward regarded as even heretical. Such a doctrine as the appellate jurisdiction may be studied in the same historical and non-polemical spirit as the doctrines of the atonement, incarnation, grace, or the sacraments.