The most striking feature of Pagan Christianity, monasticism, was due to a variety of causes. In part it had its origin in the personal character of Christ. His insistence on inward purity was not far removed from asceticism. But though monastic asceticism may have had some of its roots in later developments of Judaism, it was foreign to Judaism as a whole. Judaism was remarkable for its clearness and balance; it pushed nothing too far. Monasticism in reality was chiefly derived from eastern Paganism, from the tendency towards asceticism so common in Oriental religions. The same tendency produced another important effect on western Christianity, namely, the celibacy of the regular clergy. When this became an accepted doctrine, the finishing touch was given to clerical power. Henceforth the Roman Church was the most highly organized ecclesiastical system the world has ever seen. With no recognized interests outside his calling, every priest belonged body and soul to a vast disciplined mass which moved and acted like one man. Thus highly organized, the Church plunged into the darkest period of the Middle Ages. For the evils of this period Christianity cannot fairly be held responsible, except in so far as it contributed to the ruin of the Roman empire. Throughout it, on the whole, the Church was a centre of light, keeping alive the embers of civilization, and softening the barbarous tendencies of the time. But in passing through it Christianity suffered fearfully. The ignorance and harshness and corruption of the age were stamped ineffaceably upon it. And this was inevitable. In every civilized country at almost every time there are sure to be two forms of the general religion, one popular, the other that of the more educated classes. The popular religion, resting on ignorance, is always a mere superstition; the other religion, kept clear by partial knowledge from offensive crudities, is the recognized form. But during the worst period of the Middle Ages there was no such distinction; all religion was popular; even the highest classes were hopelessly lost in superstition. The gloom of this superstition, the shadow of the wretchedness of the age, left a lasting mark on Christianity. The terror of life was transferred to death; death was associated with the most repulsive images, and closely connected with hell. The fear of hell became the motive power of religion; to escape hell was to the Christian the end of life.[107] The superstitious elements from which Christianity is now struggling to release itself were mainly developed in its passage through this period.