The religions competing with Christianity which are left after this elimination may be classed in three categories. First come the Oriental religions native to countries lying to the south and east of the Mediterranean and therefore mainly outside the sphere of Hellenic culture until after the conquests of Alexander. These religions, born or nurtured in Asia Minor, Persia, and Egypt, so soon as Alexander had carried out his project of the marriage of Europe and Asia, poured westward in a flood which a Roman satirist compared to the Orontes emptying itself into the Tiber, and gained, according to a well-known law in the history of religions, a far greater influence over the minds of men than they had exercised in their native home. The second category comprises the many strange sects which the first Fathers of the Church grouped together under the generic name of Gnostics. The faith which these professed was not, as it is sought to show later, one founded on religion at all but rather on magic, and had long been present in germ as a sort of heresy or alternative belief underlying the worship of the gods of Olympus. Finally, there arose the ambitious religion of Manes, which aimed at sweeping into one vast synthesis or eclectic church the three religions of Zoroaster, Buddha, and Christ, which at the time of its institution divided between them the allegiance of the civilized world. Each of these categories shall be dealt with in turn; but before doing so, it may be well to say something upon the state of our knowledge concerning them. Until lately, it was a commonplace of religious history that the Catholic Church had destroyed as far as possible all traces of the religions that she had supplanted, which was picturesquely expressed in the phrase that in her victory she had burned the enemy’s camp. That this was her conscious policy may be gathered from the advice given by a Pope of the VIIth century, to “break the idols and consecrate the temples” of the heathen[19]; but of late many relics of the ancient faiths which had before escaped us have been disinterred by the care of scholars. During the last century, the lost heresiology of Hippolytus and considerable fragments of works by Gnostic authors were brought to light in circumstances to be described in their place[20], while the present decade has not only added to our stock of Gnostic fragments, but has revealed to us on the western frontier of China a hoard of Manichaean documents rich beyond our hopes[21]. These are not only valuable by reason of the information they afford, but give us ground for the belief that, as the interest in such matters becomes more widely spread, many more documents throwing light upon the subject will appear.