The answer, to be adequate, would have to be long; but perhaps we may indicate the spirit in which it ought to be conceived. Paganism was a religion, but was discarded because it was not supernatural: Neo-Platonism could not be maintained because it was not a religion. Christianity was both. It had its roots in a national faith, moulded by the trials and passions of a singularly religious people; that connection with Judaism gave Christianity a foothold in history, a definite dogmatic nucleus, which it was a true instinct in the Church never to abandon, much as certain speculative heresies might cry out against the unnatural union of a theory of redemption with one of creation, and of a world-denying ascetic idealism, which Christianity was essentially, with the national laws, the crude deism, and the strenuous worldliness of the ancient Jews. However, had the Gnostic or Manichæan heresies been victorious, Christianity would have been reduced to a floating speculation: its hard kernel of positive dogma, of Scripture, and of hieratic tradition would have been dissolved. It would have ceased to represent antiquity or to hand down an ancestral piety: in fine, by its eagerness to express itself as a perfect philosophy, it would have ceased to be a religion. How essential an element its Hebraism was, we can see now by the study of Protestantism, a group of heresies in which the practical instincts and sentimental needs of the Teutonic race found expression, by throwing over more or less completely the Catholic dogma and ritual. Yet in this revolution the Protestants maintained, or rather increased, the intensity of their religious consciousness, chiefly by absorbing the elements of Hebrew law and prophecy which they could find in the Bible and casting into that traditional form their personal conscience or their national ideals. How inadequate, on the other hand, this Hebraic element would have been to constitute the supernatural religion that was now needed, appears very clearly from the case of Philo Judæus. Here was a man, heir to all the piety and fervour of his race, who at the same time was a Neo-Platonist three hundred years before Plotinus and, as it were, the first Father of the Church. But his religion, being national, was not communicable and, being positivistic, was at fundamental odds with the spirit of his philosophy. It remained, therefore, as a merely personal treasure and heirloom, the possession of his private life: his disciples, had he had any, must either have been Jews themselves or else must have been the followers merely of his philosophy. His religion could not have passed to them; they would have regarded it, as we might regard the Christianity of Kant or the wife-worship of Comte, as a private circumstance, a detached trait, less damaging, perhaps, to his philosophy than favourable to his loyal heart.