The Church which our Lord came to establish had a twofold mission to fulfil. Her system of doctrine, on the one hand, had to be defined and perpetually maintained. But it was also necessary that it should prove itself more than a mere matter of theory,—that it should pass into practice, and command the will as well as the intellect of men. It was necessary not only to restore the image of God in man, but to establish the divine order in the world. Religion had to transform the public as well as the private life of nations, to effect a system of public right corresponding with private morality and without which it is imperfect and insecure. It was to exhibit and confirm its victory and to perpetuate its influence by calling into existence, not only works of private virtue, but institutions which are the product of the whole life of nations, and bear an unceasing testimony to their religious sentiments. The world, instead of being external to the Church, was to be adopted by her and imbued with her ideas. The first, the doctrinal or intellectual part of the work, was chiefly performed in the Roman empire, in the midst of the civilisation of antiquity and of that unparalleled intellectual excitement which followed the presence of Christ on earth. There the faith was prepared for the world whilst the world was not yet ready to receive it. The empire in which was concentrated all the learning and speculation of ancient times was by its intellectual splendour, and in spite, we might even say by reason, of its moral depravity, the fit scene of the intellectual establishment of Christianity. For its moral degradation ensured the most violent antipathy and hostility to the new faith; while the mental cultivation of the age ensured a very thorough and ingenious opposition, and supplied those striking contrasts which were needed for the full discussion and vigorous development of the Christian system. Nowhere else, and at no other period, could such advantages have been found.

But for the other, equally essential part of her work the Church met with an insurmountable obstacle, which even the official conversion of the empire and all the efforts of the Christian emperors could not remove. This obstacle resided not so much in the resistance of paganism as a religion, as in the pagan character of the State. It was from a certain political sagacity chiefly that the Romans, who tolerated all religions,[305] consistently opposed that religion which threatened inevitably to revolutionise a state founded on a heathen basis. It appeared from the first a pernicious superstition ("exitiabilem superstitionem," Tacit. Annal. xv. 44), that taught its followers to be bad subjects ("exuere patriam," Tacitus, Hist. v. 5), and to be constantly dissatisfied ("quibus praesentia semper tempora cum enormi libertate displicent," Vopiscus, Vit. Saturn. 7). This hostility continued in spite of the protestations of every apologist, and of the submissiveness and sincere patriotism of the early Christians. They were so far from recognising what their enemies so vaguely felt, that the empire could not stand in the presence of the new faith, that it was the common belief amongst them, founded perhaps on the words of St. Paul, 2 Thess. ii. 7,[306] that the Roman empire would last to the end of the world.[307]

The persecution of Julian was caused by the feeling of the danger which menaced the pagan empire from the Christian religion. His hostility was not founded on his attachment to the old religion of Rome, which he did not attempt to save. He endeavoured to replace it by a new system which was to furnish the State with new vigour to withstand the decay of the old paganism and the invasion of Christianity. He felt that the old religious ideas in which the Roman State had grown up had lost their power, and that Rome could only be saved by opposing at all hazards the new ideas. He was inspired rather with a political hatred of Christianity than with a religious love of paganism. Consequently Christianity was the only religion he could not tolerate. This was the beginning of the persecution of the Church on principles of liberalism and religious toleration, on the plea of political necessity, by men who felt that the existing forms of the State were incompatible with her progress. It is with the same feeling of patriotic aversion for the Church that Symmachus says (Epist. x. 61): "We demand the restoration of that religion which has so long been beneficial to the State ... of that worship which has subdued the universe to our laws, of those sacrifices which repulsed Hannibal from our walls and the Gauls from the Capitol."

Very soon after the time of Constantine it began to appear that the outward conversion of the empire was a boon of doubtful value to religion. "Et postquam ad Christianos principes venerint, potentia quidem et divitiis major sed virtutibus minor facta est," says St. Jerome (in Vita Malchi). The zeal with which the emperors applied the secular arm for the promotion of Christianity was felt to be incompatible with its spirit and with its interest as well. "Religion," says Lactantius (Inst. Div. v. 19), "is to be defended by exhorting, not by slaying, not by severity, but by patience; not by crime, but by faith: ... nihil enim est tam voluntarium quam religio."[308] "Deus," says St. Hilary of Poitiers ("ad Constantium," Opp. i. p. 1221 C), "obsequio non eget necessario, non requirit coactam confessionem."[309] St. Athanasius and St. John Chrysostom protest in like manner against the intemperate proselytism of the day.[310] For the result which followed the general adoption of Christianity threw an unfavourable light on the motives which had caused it. It became evident that the heathen world was incapable of being regenerated, that the weeds were choking the good seed. The corruption increased in the Church to such a degree that the Christians, unable to divest themselves of the Roman notion of the orbis terrarum, deemed the end of the world at hand. St. Augustine (sermo cv.) rebukes this superstitious fear: "Si non manet civitas quae nos carnaliter genuit, manet quae nos spiritualiter genuit. Numquid (Dominus) dormitando aedificium suum perdidit, aut non custodiendo hostes admisit?... Quid expavescis quia pereunt regna terrena? Ideo tibi coeleste promissum est, ne cum terrenis perires.... Transient quae fecit ipse Deus; quanto citius quod condidit Romulus.... Non ergo deficiamus, fratres: finis erit terrenis omnibus regnis."[311] But even some of the fathers themselves were filled with despair at the spectacle of the universal demoralisation: "Totius mundi una vox Christus est ... Horret animus temporum nostrorum ruinas persequi.... Romanus orbis ruit, et tamen cervix nostra erecta non flectitur.... Nostris peccatis barbari fortes sunt. Nostris vitiis Romanus superatur exercitus.... Nec amputamus causas morbi, ut morbus pariter auferatur.... Orbis terrarum ruit, in nobis peccata non ruunt."[312] St. Ambrose announces the end still more confidently: "Verborum coelestium nulli magis quam nos testes sumus, quos mundi finis invenit.... Quia in occasu saeculi sumus, praecedunt quaedam aegritudines mundi."[313] Two generations later Salvianus exclaims: "Quid est aliud paene omnis coetus Christianorum quam sentina vitiorum?"[314] And St. Leo declares, "Quod temporibus nostris auctore diabolo sic vitiata sunt omnia, ut paene nihil sit quod absque idolatria transigatur."[315]

When, early in the fifth century, the dismemberment of the Western empire commenced, it was clear that Christianity had not succeeded in reforming the society and the polity of the ancient world. It had arrested for a time the decline of the empire, but after the Arian separation it could not prevent its fall. The Catholics could not dissociate the interests of the Church and those of the Roman State, and looked with patriotic as well as religious horror at the barbarians by whom the work of destruction was done. They could not see that they had come to build up as well as to destroy, and that they supplied a field for the exercise of all that influence which had failed among the Romans. It was very late before they understood that the world had run but half its course; that a new skin had been prepared to contain the new wine; and that the barbarous tribes were to justify their claim to the double inheritance of the faith and of the power of Rome. There were two principal things which fitted them for their vocation. The Romans had been unable to be the instruments of the social action of Christianity on account of their moral depravity. It was precisely for those virtues in which they were most deficient that their barbarous enemies were distinguished. Salvianus expresses this in the following words (De Gubern. Dei, vii. 6): "Miramur si terrae ... nostrorum omnium a Deo barbaris datae sunt, cum eas quae Romani polluerant fornicatione, nunc mundent barbari castitate?"[316] Whilst thus their habits met half-way the morality of the Christian system, their mythology, which was the very crown and summit of all pagan religions, predisposed them in like manner for its adoption, by predicting its own end, and announcing the advent of a system which was to displace its gods. "It was more than a mere worldly impulse," says a famous northern divine, "that urged the northern nations to wander forth, and to seek, like birds of passage, a milder clime." We cannot, however, say more on the predisposition for Christianity of that race to whose hands its progress seems for ever committed, or on the wonderful facility with which the Teutonic invaders accepted it, whether presented to them in the form of Catholicism or of Arianism.[317] The great marvel in their history, and their chief claim to the dominion of the world, was, that they had preserved so long, in the bleak regions in which the growth of civilisation was in every way retarded, the virtues together with the ignorance of the barbarous State.

At a time when Arianism was extinct in the empire, it assumed among the Teutonic tribes the character of a national religion, and added a theological incitement to their animosity against the Romans. The Arian tribes, to whom the work of destruction was committed, did it thoroughly. But they soon found that their own preservation depended on their submission to the Church. Those that persisted in their heresy were extirpated. The Lombards and Visigoths saved themselves by a tardy conversion from the fate with which they were threatened so long, as their religion estranged them from the Roman population, and cut them off from the civilisation of which the Church was already the only guardian. For centuries the pre-eminence in the West belonged to that race which alone became Catholic at once, and never swerved from its orthodoxy. It is a sense of the importance of this fidelity which dictated the well-known preamble of the Salic law: "Gens Francorum inclita, Deo auctore condita, ad Catholicam fidem conversa et immunis ab haeresi," etc.[318]

Then followed the ages which are not unjustly called the Dark Ages, in which were laid the foundations of all the happiness that has been since enjoyed, and of all the greatness that has been achieved, by men. The good seed, from which a new Christian civilisation sprang, was striking root in the ground. Catholicism appeared as the religion of masses. In those times of simple faith there was no opportunity to call forth an Augustine or an Athanasius. It was not an age of conspicuous saints, but sanctity was at no time so general. The holy men of the first centuries shine with an intense brilliancy from the midst of the surrounding corruption. Legions of saints—individually for the most part obscure, because of the atmosphere of light around them—throng the five illiterate centuries, from the close of the great dogmatic controversies to the rise of a new theology and the commencement of new contests with Hildebrand, Anselm, and Bernard. All the manifestations of the Catholic spirit in those days bear a character of vastness and popularity. A single idea—the words of one man—electrified hundreds of thousands. In such a state of the world, the Christian ideas were able to become incarnate, so to speak, in durable forms, and succeeded in animating the political institutions as well as the social life of the nations.

The facility with which the Teutonic ideas of Government shaped themselves to the mould of the new religion, was the second point in which that race was so peculiarly adapted for the position it has ever since occupied towards Christianity. They ceased to be barbarians only in becoming Christians. Their political system was in its infancy, and was capable of being developed variously, according to the influences it might undergo. There was no hostile civilisation to break down, no traditions to oppose which were bound up with the recollections of the national greatness. The State is so closely linked with religion, that no nation that has changed its religion has ever survived in its old political form. In Rome it had proved to be impossible to alter the system, which for a thousand years had animated every portion of the State; it was incurably pagan. The conversion of the people and the outward alliance with the Church could not make up for this inconsistency.

But the Teutonic race received the Catholic ideas wholly and without reserve. There was no region into which they failed to penetrate. The nation was collectively Catholic, as well as individually. The union of the Church with the political system of the Germans was so complete, that when Hungary adopted the religion of Rome, it adopted at the same time, as a natural consequence, the institutions of the empire. The ideas of Government which the barbarians carried with them into every land which they conquered were always in substance the same. The Respublica Christiana of the Middle Ages, consisting of those States in which the Teutonic element combined with the Catholic system, was governed by nearly the same laws. The mediæval institutions had this also in common, that they grew up everywhere under the protection and guidance of the Church; and whilst they subsisted in their integrity, her influence in every nation, and that of the Pope over all the nations, attained their utmost height. In proportion as they have since degenerated or disappeared, the political influence of religion has declined. As we have seen that the Church was baffled in the full performance of her mission before Europe was flooded by the great migration, so it may be said that she has never permanently enjoyed her proper position and authority in any country where it did not penetrate. No other political system has yet been devised, which was consistent with the full development and action of Catholic principles, but that which was constructed by the northern barbarians who destroyed the Western empire.

From this it does not seem too much to conclude, that the Catholic religion tends to inspire and transform the public as well as the private life of men; that it is not really master of one without some authority over the other. Consequently, where the State is too powerful by long tradition and custom, or too far gone in corruption, to admit of the influence of religion, it can only prevail by ultimately destroying the political system. This helps us to understand the almost imperceptible progress of Christianity against Mahometanism, and the slowness of its increase in China, where its growth must eventually undermine the whole fabric of government. On the other hand, we know with what ease comparatively savage tribes—as the natives of California and Paraguay—were converted to a religion which first initiated them in civilisation and government. There are countries in which the natural conditions are yet wanting for the kingdom of grace. There is a fulness of time for every nation—a time at which it first becomes capable of receiving the faith.[319] It is not harder to believe that certain political conditions are required to make a nation fit for conversion than that a certain degree of intellectual development is indispensable; that the language, for instance, must have reached a point which that of some nations has not attained before it is capable of conveying the truths of Christianity.