These unhappy exiles from social life were impelled by the dark and implacable genius of superstition. Their mutual resolution was supported by the example of millions, of either sex, of every age, and of every rank; and each proselyte who entered the gates of a monastery, was persuaded that he trod the steep and thorny path of eternal happiness. But the operation of these religious motives was variously determined by the temper and situation of mankind. Reason might subdue, or passion might suspend, their influence: but they acted most forcibly on the infirm minds of children and females; they were strengthened by secret remorse, or accidental misfortune; and they might derive some aid from the temporal considerations of vanity or interest. It was naturally supposed, that the pious and humble monks, who had renounced the world to accomplish the work of their salvation, were the best qualified for the spiritual government of the Christians. The reluctant hermit was torn from his cell, and seated, amidst the acclamations of the people, on the episcopal throne: the monasteries of Egypt, of Gaul, and of the East, supplied a regular succession of saints and bishops; and ambition soon discovered the secret road which led to the possession of wealth and honors. The popular monks, whose reputation was connected with the fame and success of the order, assiduously labored to multiply the number of their fellow-captives. They insinuated themselves into noble and opulent families; and the specious arts of flattery and seduction were employed to secure those proselytes who might bestow wealth or dignity on the monastic profession. The indignant father bewailed the loss, perhaps, of an only son; the credulous maid was betrayed by vanity to violate the laws of nature; and the matron aspired to imaginary perfection, by renouncing the virtues of domestic life. Paula yielded to the persuasive eloquence of Jerome; and the profane title of mother-in-law of God tempted that illustrious widow to consecrate the virginity of her daughter Eustochium. By the advice, and in the company, of her spiritual guide, Paula abandoned Rome and her infant son; retired to the holy village of Bethlem; founded a hospital and four monasteries; and acquired, by her alms and penance, an eminent and conspicuous station in the Catholic church. Such rare and illustrious penitents were celebrated as the glory and example of their age; but the monasteries were filled by a crowd of obscure and abject plebeians, who gained in the cloister much more than they had sacrificed in the world. Peasants, slaves, and mechanics, might escape from poverty and contempt to a safe and honorable profession; whose apparent hardships are mitigated by custom, by popular applause, and by the secret relaxation of discipline. The subjects of Rome, whose persons and fortunes were made responsible for unequal and exorbitant tributes, retired from the oppression of the Imperial government; and the pusillanimous youth preferred the penance of a monastic, to the dangers of a military, life. The affrighted provincials of every rank, who fled before the Barbarians, found shelter and subsistence: whole legions were buried in these religious sanctuaries; and the same cause, which relieved the distress of individuals, impaired the strength and fortitude of the empire.
The monastic profession of the ancients was an act of voluntary devotion. The inconstant fanatic was threatened with the eternal vengeance of the God whom he deserted; but the doors of the monastery were still open for repentance. Those monks, whose conscience was fortified by reason or passion, were at liberty to resume the character of men and citizens; and even the spouses of Christ might accept the legal embraces of an earthly lover. The examples of scandal, and the progress of superstition, suggested the propriety of more forcible restraints. After a sufficient trial, the fidelity of the novice was secured by a solemn and perpetual vow; and his irrevocable engagement was ratified by the laws of the church and state. A guilty fugitive was pursued, arrested, and restored to his perpetual prison; and the interposition of the magistrate oppressed the freedom and the merit, which had alleviated, in some degree, the abject slavery of the monastic discipline. The actions of a monk, his words, and even his thoughts, were determined by an inflexible rule, or a capricious superior: the slightest offences were corrected by disgrace or confinement, extraordinary fasts, or bloody flagellation; and disobedience, murmur, or delay, were ranked in the catalogue of the most heinous sins. A blind submission to the commands of the abbot, however absurd, or even criminal, they might seem, was the ruling principle, the first virtue of the Egyptian monks; and their patience was frequently exercised by the most extravagant trials. They were directed to remove an enormous rock; assiduously to water a barren staff, that was planted in the ground, till, at the end of three years, it should vegetate and blossom like a tree; to walk into a fiery furnace; or to cast their infant into a deep pond: and several saints, or madmen, have been immortalized in monastic story, by their thoughtless and fearless obedience. The freedom of the mind, the source of every generous and rational sentiment, was destroyed by the habits of credulity and submission; and the monk, contracting the vices of a slave, devoutly followed the faith and passions of his ecclesiastical tyrant. The peace of the Eastern church was invaded by a swarm of fanatics, incapable of fear, or reason, or humanity; and the Imperial troops acknowledged, without shame, that they were much less apprehensive of an encounter with the fiercest Barbarians.
(The History of the decline and Fall of the Roman Empire, Vol. 4, Chap. 37, pgs. 9 - 13 of the Everyman's Library edition)