The irresistible power of the Roman emperors was displayed in the important and dangerous change of the national religion. The terrors of a military force silenced the faint and unsupported murmurs of the Pagans, and there was reason to expect, that the cheerful submission of the Christian clergy, as well as people, would be the result of conscience and gratitude. It was long since established, as a fundamental maxim of the Roman constitution, that every rank of citizens was alike subject to the laws, and that the care of religion was the right as well as duty of the civil magistrate. Constantine and his successors could not easily persuade themselves that they had forfeited, by their conversion, any branch of the Imperial prerogatives, or that they were incapable of giving laws to a religion which they had protected and embraced. The emperors still continued to exercise a supreme jurisdiction over the ecclesiastical order, and the sixteenth book of the Theodosian code represents, under a variety of titles, the authority which they assumed in the government of the Catholic church.
But the distinction of the spiritual and temporal powers, which had never been imposed on the free spirit of Greece and Rome, was introduced and confirmed by the legal establishment of Christianity. The office of supreme pontiff, which, from the time of Numa to that of Augustus, had always been exercised by one of the most eminent of the senators, was at length united to the Imperial dignity. The first magistrate of the state, as often as he was prompted by superstition or policy, performed with his own hands the sacerdotal functions; nor was there any order of priests, either at Rome or in the provinces, who claimed a more sacred character among men, or a more intimate communication with the gods. But in the Christian church, which instrusts the service of the altar to a perpetual succession of consecrated ministers, the monarch, whose spiritual rank is less honorable than that of the meanest deacon, was seated below the rails of the sanctuary, and confounded with the rest of the faithful multitude. The emperor might be saluted as the father of his people, but he owed a filial duty and reverence to the fathers of the church; and the same marks of respect, which Constantine had paid to the persons of saints and confessors, were soon exacted by the pride of the episcopal order. A secret conflict between the civil and ecclesiastical jurisdictions embarrassed the operation of the Roman government; and a pious emperor was alarmed by the guilt and danger of touching with a profane hand the ark of the covenant. The separation of men into the two orders of the clergy and of the laity was, indeed, familiar to many nations of antiquity; and the priests of India, of Persia, of Assyria, of Judea, of Æthiopia, of Egypt, and of Gaul, derived from a celestial origin the temporal power and possessions which they had acquired. These venerable institutions had gradually assimilated themselves to the manners and government of their respective countries; but the opposition or contempt of the civil power served to cement the discipline of the primitive church. The Christians had been obliged to elect their own magistrates, to raise and distribute a peculiar revenue, and to regulate the internal policy of their republic by a code of laws, which were ratified by the consent of the people and the practice of three hundred years. When Constantine embraced the faith of the Christians, he seemed to contract a perpetual alliance with a distinct and independent society; and the privileges granted or confirmed by that emperor, or by his successors, were accepted, not as the precarious favors of the court, but as the just and inalienable rights of the ecclesiastical order.
The Catholic church was administered by the spiritual and legal jurisdiction of eighteen hundred bishops; of whom one thousand were seated in the Greek, and eight hundred in the Latin, provinces of the empire. The extent and boundaries of their respective dioceses had been variously and accidentally decided by the zeal and success of the first missionaries, by the wishes of the people, and by the propagation of the gospel. Episcopal churches were closely planted along the banks of the Nile, on the sea-coast of Africa, in the proconsular Asia, and through the southern provinces of Italy. The bishops of Gaul and Spain, of Thrace and Pontus, reigned over an ample territory, and delegated their rural suffragans to execute the subordinate duties of the pastoral office. A Christian diocese might be spread over a province, or reduced to a village; but all the bishops possessed an equal and indelible character: they all derived the same powers and privileges from the apostles, from the people, and from the laws. While the civil and military professions were separated by the policy of Constantine, a new and perpetual order of ecclesiastical ministers, always respectable, sometimes dangerous, was established in the church and state. The important review of their station and attributes may be distributed under the following heads: I. Popular Election. II. Ordination of the Clergy. III. Property. IV. Civil Jurisdiction. V. Spiritual censures. VI. Exercise of public oratory. VII. Privilege of legislative assemblies.
I. The freedom of election subsisted long after the legal establishment of Christianity; and the subjects of Rome enjoyed in the church the privilege which they had lost in the republic, of choosing the magistrates whom they were bound to obey. As soon as a bishop had closed his eyes, the metropolitan issued a commission to one of his suffragans to administer the vacant see, and prepare, within a limited time, the future election. The right of voting was vested in the inferior clergy, who were best qualified to judge of the merit of the candidates; in the senators or nobles of the city, all those who were distinguished by their rank or property; and finally in the whole body of the people, who, on the appointed day, flocked in multitudes from the most remote parts of the diocese, and sometimes silenced by their tumultuous acclamations, the voice of reason and the laws of discipline. These acclamations might accidentally fix on the head of the most deserving competitor; of some ancient presbyter, some holy monk, or some layman, conspicuous for his zeal and piety. But the episcopal chair was solicited, especially in the great and opulent cities of the empire, as a temporal rather than as a spiritual dignity. The interested views, the selfish and angry passions, the arts of perfidy and dissimulation, the secret corruption, the open and even bloody violence which had formerly disgraced the freedom of election in the commonwealths of Greece and Rome, too often influenced the choice of the successors of the apostles. While one of the candidates boasted the honors of his family, a second allured his judges by the delicacies of a plentiful table, and a third, more guilty than his rivals, offered to share the plunder of the church among the accomplices of his sacrilegious hopes. The civil as well as ecclesiastical laws attempted to exclude the populace from this solemn and important transaction. The canons of ancient discipline, by requiring several episcopal qualifications, of age, station, etc., restrained, in some measure, the indiscriminate caprice of the electors. The authority of the provincial bishops, who were assembled in the vacant church to consecrate the choice of the people, was interposed to moderate their passions and to correct their mistakes. The bishops could refuse to ordain an unworthy candidate, and the rage of contending factions sometimes accepted their impartial mediation. The submission, or the resistance, of the clergy and people, on various occasions, afforded different precedents, which were insensibly converted into positive laws and provincial customs; but it was every where admitted, as a fundamental maxim of religious policy, that no bishop could be imposed on an orthodox church, without the consent of its members. The emperors, as the guardians of the public peace, and as the first citizens of Rome and Constantinople, might effectually declare their wishes in the choice of a primate; but those absolute monarchs respected the freedom of ecclesiastical elections; and while they distributed and resumed the honors of the state and army, they allowed eighteen hundred perpetual magistrates to receive their important offices from the free suffrages of the people. It was agreeable to the dictates of justice, that these magistrates should not desert an honorable station from which they could not be removed; but the wisdom of councils endeavored, without much success, to enforce the residence, and to prevent the translation, of bishops. The discipline of the West was indeed less relaxed than that of the East; but the same passions which made those regulations necessary, rendered them ineffectual. The reproaches which angry prelates have so vehemently urged against each other, serve only to expose their common guilt, and their mutual indiscretion.
II. The bishops alone possessed the faculty of spiritual generation: and this extraordinary privilege might compensate, in some degree, for the painful celibacy which was imposed as a virtue, as a duty, and at length as a positive obligation. The religions of antiquity, which established a separate order of priests, dedicated a holy race, a tribe or family, to the perpetual service of the gods. Such institutions were founded for possession, rather than conquest. The children of the priests enjoyed, with proud and indolent security, their sacred inheritance; and the fiery spirit of enthusiasm was abated by the cares, the pleasures, and the endearments of domestic life. But the Christian sanctuary was open to every ambitious candidate, who aspired to its heavenly promises or temporal possessions. This office of priests, like that of soldiers or magistrates, was strenuously exercised by those men, whose temper and abilities had prompted them to embrace the ecclesiastical profession, or who had been selected by a discerning bishop, as the best qualified to promote the glory and interest of the church. The bishops (till the abuse was restrained by the prudence of the laws) might constrain the reluctant, and protect the distressed; and the imposition of hands forever bestowed some of the most valuable privileges of civil society. The whole body of the Catholic clergy, more numerous perhaps than the legions, was exempted by the emperors from all service, private or public, all municipal offices, and all personal taxes and contributions, which pressed on their fellow-citizens with intolerable weight; and the duties of their holy profession were accepted as a full discharge of their obligations to the republic. Each bishop acquired an absolute and indefeasible right to the perpetual obedience of the clerk whom he ordained: the clergy of each episcopal church, with its dependent parishes, formed a regular and permanent society; and the cathedrals of Constantinople and Carthage maintained their peculiar establishment of five hundred ecclesiastical ministers. Their ranks and numbers were insensibly multiplied by the superstition of the times, which introduced into the church the splendid ceremonies of a Jewish or Pagan temple; and a long train of priests, deacons, sub-deacons, acolythes, exorcists, readers, singers, and doorkeepers, contributed, in their respective stations, to swell the pomp and harmony of religious worship. The clerical name and privileges were extended to many pious fraternities, who devoutly supported the ecclesiastical throne. Six hundred parabolani, or adventurers, visited the sick at Alexandria; eleven hundred copiâtoe, or grave-diggers, buried the dead at Constantinople; and the swarms of monks, who arose from the Nile, overspread and darkened the face of the Christian world. (The History of the decline and Fall of the Roman Empire, Vol. 2, Chap. 20, pgs. 277 - 284 of the Everyman's Library edition)