The line of separation between the laity and the clergy was widened and deepened by the enforcement of the canon requiring celibacy on the part of all concerned in the ministry of the altar. Revived about the middle of the eleventh century, and enforced after an obstinate struggle of a hundred years, the compulsory celibacy of the priesthood divided them from the people, preserved intact the vast acquisitions of the Church, and furnished it with an innumerable army whose aspirations and ambition were necessarily restricted within its circle. The man who entered the service of the Church was no longer a citizen. He owed no allegiance superior to that assumed in his ordination. He was released from the distraction of family cares and the seduction of family ties. The Church was his country and his home, and its interests were his own. The moral, intellectual, and physical forces which, throughout the laity, were divided between the claims of patriotism, the selfish struggle for advancement, the provision for wife and children, were in the Church consecrated to a common end, in the success of which all might hope to share, while all were assured of the necessities of existence, and were relieved of anxiety as to the future. The Church, moreover, offered the only career open to men of all ranks and stations. In the sharply-defined class distinctions of the feudal system advancement was almost impossible to one not born within the charmed circle of gentle blood. In the Church, however much rank and family connections might assist in securing promotion to high place, yet talent and energy could always make themselves felt despite lowliness of birth. Urban II. and Adrian IV. sprang from the humblest origin; Alexander V. had been a beggar-boy; Gregory VII. was the son of a carpenter; Benedict XII., of a baker; Nicholas V., of a poor physician; Sixtus IV., of a peasant; Urban IV. and John XXII. were sons of cobblers, and Benedict XI. and Sixtus V. of shepherds; in fact, the annals of the hierarchy are full of those who rose from the lowest ranks of society to the most commanding positions. The Church thus constantly recruited its ranks with fresh blood. Free from the curse of hereditary descent, through which crowns and coronets frequently lapsed into weak and incapable hands, it called into its service an indefinite amount of restless vigor for which there was no other sphere of action, and which, when once enlisted, found itself perforce identified irrevocably with the body which it had joined. The character of the priest was indelible; the vows taken at ordination could not be thrown aside; the monk, when once admitted to the cloister, could not abandon his order unless it were to enter another of more rigorous observance. The Church Militant was thus an army encamped on the soil of Christendom, with its outposts everywhere, subject to the most efficient discipline, animated with a common purpose, every soldier panoplied with