Of all the early Popes, save Leo I and Gregory I, it is true that we may be tolerably at home in the history of their times without knowing much about them. No Pope is ranked among the leading Western Fathers. The only considerable theologian who occupied the Holy See, before the year 1000, is Gregory I; and the highest praise which we can give his writings is that they imparted new life to some ideas of St. Augustine. It is as statesmen, not as thinkers, that the early Popes appeal to our attention. Yet their practical achievements scarcely account for the reverence which they inspired. The one great mission which Rome set on foot was that of Augustine to England. The other evangelists of the Dark Ages found their inspiration elsewhere, in the monasteries of Ireland or of Gaul and Germany. If we consider the progress of theological science, and of ecclesiastical organisation, we find that the great controversies were resolved, and the great legislative assemblies convened, in the Eastern Empire. It was but rarely that Rome asserted her right to speak in the name even of the Western Church; the record of the early Popes who attained to such a momentary pre-eminence was not such as the West could recollect with satisfaction. In fact, it was due to other causes than the merits of individual Popes that Rome became and remained the religious metropolis of Europe.
How, then, are we to account for her triumphant progress? Hobbes suggested one explanation when he called the Papacy "the ghost of the Roman Empire." And it is true that the later Emperors found it convenient to confer special privileges on the bishops of their ancient capital. But they adopted this policy too late, when reverence for the Empire was already declining in the West. By imperial grants the Papacy gained no substantial powers, while individual Popes lost credit and independence by their special connection with the New Rome on the Bosporus. They were compelled to play an ignominious part in the squabbles of the Eastern Churches, they were loaded with onerous secular duties; they became the emblems and the agents of an alien tyranny, mistrusted alike by the barbarian invaders and the nominal subjects of the Empire.
Other critics have explained the prestige of the Papacy as the fruit of successful impostures. For this hypothesis there is little to be said. One or two Popes, not the greatest, have condescended to use forged title-deeds. But the effect of these frauds has been much exaggerated. The most famous of them are the Donation of Constantine and the False Decretals. The former, though probably of Roman origin, was little used at Rome, and only served to justify the modest beginnings of the temporal power. The latter are of more importance, and are sometimes regarded as opening an era of new pretensions. In fact they are little more than reiterations and amplifications of very ancient claims. Though frequently quoted by the canon lawyers, they are not indispensable links in the claim of historical proofs and precedents. They are chiefly significant as attesting the general desire of churchmen to find some warrant for a vigorous exercise of the papal prerogative. A primate with real powers was desired, not only by the clergy of the national churches as a bulwark against the brutal oppression of the State, but also by all religious thinkers as a symbol of corporate unity and a guarantee of doctrinal uniformity.
No theory can be regarded as supplying a satisfactory explanation of papal authority, unless it explains this general belief in the necessity for a visible Head of the Western Church. In part the necessity was political. Exposed to the common danger of secular tyranny, the national churches looked for safety in federation; and they notified their union in the only way that uneducated laymen could understand, by announcing their subjection to a single spiritual sovereign. But there remained the problem of justifying this act of independence amounting to rebellion. The justification was found in two arguments, the one historical, the other doctrinal; the one based upon the Roman legend of St. Peter, the other on the acknowledged importance of holding fast to right tradition. Each of these arguments calls for some consideration.
St. Peter, says the legend, was invested with the primacy among the Apostles; such is the plain meaning of the Saviour's declaration, Tu es Petrus. St. Peter founded the Roman Church and instituted the Roman bishopric. To Linus, the first bishop, Peter bequeathed his Divine commission and his knowledge of the Christian verities. From Linus these gifts descended without diminution to one after another in the unbroken chain of his successors. Hence Rome is entitled to the same pre-eminence among the churches which Peter held among his brethren. To examine the historical basis of the legend would be a lengthy and unprofitable task. Of St. Peter's connection with the Eternal City we know nothing certain, except that he preached and suffered there. If bishops existed in his time, there is some reason for thinking that the office was collegiate, and that the committee of bishops was less important then in the spiritual life of the community than at a later time. Not until the second century did the episcopate become monarchical and the holder of the office the supreme authority within the Church by which he was elected. The change was complete by the time of Irenaeus, who wrote circa 180 A.D.; to him we owe our earliest catalogue of Roman bishops, beginning with Linus and ending with Eleutherus, the twelfth from Peter and the contemporary of Irenaeus. The later names in the list are doubtless those of authentic bishops; the earlier may be in some sense historical, the names of famous presbyters or of men who made their mark on the old episcopal committee. A point of secondary interest is that Irenaeus speaks of bishops, not of Popes; this title came into use a hundred years after his time. More important is the fact that, in the third century, when our documents become more copious, Rome is generally recognised as first in dignity among the churches (ecclesia principalis), but has no appellate jurisdiction and no legislative powers. It is only admitted that, when disputes arise on points of tradition, her testimony is entitled to special honour, as that of a church which preserves the memory of Peter's teaching. As doctrinal controversies become more acute and more fundamental, the importance of tradition is emphasised, the authority of those who voice it is magnified. Ultimately all the pretensions of the Holy See are founded on the claim that she possesses the only undefiled tradition. But it was not until long after the third century that the consequences of the claim were realised even by the claimants.
If we were invited, at the present day, to suggest a means of conserving intact a body of doctrinal definitions and disciplinary law, we should not naturally select some mode of oral transmission as the safest available. Yet this expedient has found much favour in the past. Even among the Jews, with their extreme respect for sacred books, the written word was made of none account by the traditions of expositors. The votaries of the Greek mystic cults deliberately avoided writing down their more important formulae. Several considerations were in favour of this curious policy. There were no scientific canons for the interpretation of written texts; allegorising commentators read their own wild fancies into the plainest sentences. The only way of meeting them was to fall back on the traditional interpretation. We use the texts to test the traditions; but criticism in its early stages pursues the opposite course, and as a natural consequence rates tradition above Scripture. Other reasons which discouraged the use of writing were, first, the fear that no literary skill might be equal to the difficulty of accurate statement; secondly, the natural reluctance of the religious mind to let the deepest truths be exposed to the vulgar scoffs and criticism of the uninitiated; thirdly, some remnant of the primitive superstition that the formulae of a ritual are magic spells, which would lose their potency if published to the world; and, finally, the natural instinct of a sacerdotal class to reserve the knowledge of deepest mysteries to a select inner circle. For all these reasons a jealously guarded tradition, commonly designated as the arcana or secreta, was to be found in all the early Christian Churches. To give a few examples: the Apostles' Creed, the distinctive symbol of the Roman Church, was preserved by oral tradition only down to the fourth century, and was not imparted to any catechumen until the time of his baptism. The minute rules of penitential discipline were first committed to writing by Theodore of Tarsus, Archbishop of Canterbury, towards the close of the seventh century; and this innovation was sharply criticised by some ecclesiastical synods. Most remarkable of all is the reluctance of the churches to write down the essential, operative parts of the Mass. Written copies are first mentioned in the fourth century, and it was not until a much later period that the diversities of local tradition were corrected by the issue of a standard text. It might be supposed that the non-existence of official copies was due to the want of any device, such as printing, by which they could be cheaply multiplied. But there is a curious fact which suggests that publication was considered undesirable. One section of the Canon of the Mass was called the secret part (secretum), and was recited by the celebrant in an undertone, that it might not become known to the congregation. Similarly, all literary exposition of such central doctrines as the Atonement, or the Trinity, was deprecated by early theologians, who pass by them with the remark that they are known to the initiate.
This cult of secrecy engendered difficulties which are written large upon the page of history. Disputes arose about the wording of the creeds, about the canon of the Scriptures, about the number and nature of the mortal sins, and the penances which they should entail. Periodically a curious investigator raised a storm by claiming that he had discovered a flaw in the traditional formulae, or a mistake in the sense which was currently attached to them. The one way of meeting such doubts was to compare the traditions of the older churches. This could be done by a provincial synod or a general council. But of these tribunals the former was unsatisfactory, as its decisions were of merely local validity and might be overruled by the voice of the universal Church. The general council was hard to convene, particularly after a rift had opened between the Eastern and the Western Churches. It was easier to select as the final arbiter a bishop whose knowledge of tradition was derived from an apostolic predecessor. In the East there were three such sees (Antioch, Jerusalem, Alexandria), but in the West Rome alone satisfied the necessary conditions. And the Bishops of Rome could claim, with some show of reason, that their tradition was derived from a worthier source, and had been better guarded against contagion, than that of any other Apostolic Church. Was it not a well-established fact that Rome had preserved an unwavering front in the face of the heretical Arius, when even Antioch, Jerusalem, and Alexandria had wavered?
Recourse to Rome as the oracle of the faith was so obvious an expedient, given the prevailing attitude towards tradition, that we can only be surprised to find how slow and gradual was the triumph of the Roman claims. The victory of logic was retarded both by the pride and by the common sense of the other Western Churches. On the one hand, the See of Carthage clung to the old ideal of Christendom as a confederation of self-governing churches, which might consult one another as they pleased but recognised no superior except a general council. Carthage carried with her the whole Church of Africa, and furnished an example which less illustrious communities were proud to imitate. The conquest of Africa by the Vandal heretics was necessary before the African Christians would consent to look to Rome as their spiritual metropolis. On the other hand, the rulings of the Roman bishops were justly suspected of being tempered by regard for expediency. Sometimes they relaxed penitential discipline, for fear of driving the weaker brethren to apostasy. Sometimes, under pressure from Constantinople, they proposed an ambiguous compromise with heresy. Such considerations were but gradually overborne by the pressure of circumstances. The spread of Arianism and the irruption of the Teutons (themselves often Arians) at length compelled the churches to take the obvious means of preserving their imperilled uniformity and union.
It is in the acts of the Council of Sardica (343 A.D.) that we find the first explicit recognition of the Pope as an arbiter and (we may almost say) a judge of appeal. This council was merely a gathering of Western bishops, and the canons which it passed were never accepted by the Church of Africa. So doubtful was their validity that the Popes of the next generation disingenuously asserted that they had been passed at the earlier and more famous Council of Nicaea (325). Yet even at Sardica the Pope was only endowed with one definite prerogative. Henceforward any bishop condemned by a provincial synod might appeal to him; he could then order a second trial to be held, and could send his legates to sit among the judges; but he could not hear the case in his own court. More striking than this decree are the words of the letter which the Council addressed to Pope Julius: "It will be very right and fitting for the priests of the Lord, from every province, to refer to their Head, that is to the See of Peter." This recommendation was readily obeyed by the Churches of Gaul and Spain. Questions from their bishops poured in upon the Popes, who began to give their decisions in the form of open letters, and to claim for these letters the binding force of law. Pope Liberius (352-366 A.D.) appears to have commenced the practice, although the earliest of the extant "Decretals" is from the pen of Pope Siricius (385). Sixty years after Siricius' time, when the Western Empire was in its death-agony, this claim to legislative power was formally confirmed by the Emperor Valentinian III (445). But for some time after the Council of Sardica the new prerogative was used with the greatest caution. The Popes of that period use every precaution to make their oracular answers inoffensive. They assure their correspondents that Rome enjoins no novelties; that she does not presume to decide any point on which tradition is silent; that she is merely executing a mandate which general councils have laid upon her. Those who evince respect for her claims are overwhelmed with compliments. A decretal of Innocent I (402-417) begins as follows:—
"Very dear brother, the Church's rules of life and conduct are well known to a priest of your merit and dignity. But since you have urgently inquired of us concerning the rule which the Roman Church prescribes, we bow to your desire and herewith send you our rules of discipline, arranged in order."