Such, in brief outline, has been the interaction of moral and intellectual forces operating within the limits of established systems, and of the nations governed by them. But there are added factors, intensifying the forces on each side, when alien are brought into rivalry and collision with national deities. In such a contest, besides the moral and spiritual sentiments and the household sanctities, which have become intertwined with the internal deities, national pride is also enlisted, and patriotism. But on the other side is enlisted the charm of novelty, and the consciousness of fault and failure in the home system. Every system imported to a foreign land leaves behind its practical shortcomings, puts its best foot forward--namely, its theoretical foot--and has the advantage of suggesting a way of escape from the existing routine which has become oppressive. Napoleon I. said that no people profoundly attached to the institutions of their country can be conquered; but what people are attached to the priestly system over them? That internal dissatisfaction which, in secular government, gives welcome to a dashing Corsican or a Prince of Orange, has been the means of introducing many an alien religion, and giving to many a prophet the honour denied him in his own country. Buddha was a Hindu, but the triumph of his religion is not in India; Zoroaster was a Persian, but there are no Parsees in Persia; Christianity is hardly a colonist even in the native land of Christ. These combinations and changes were not effected without fierce controversies, ferocious wars, or persecutions, and the formation of many devils. Nothing is more normal in ancient systems than the belief that the gods of other nations are devils. The slaughter of the priests of Baal corresponds with the development of their god into Beelzebub. In proportion to the success of Olaf in crushing the worshippers of Odin, their deity is steadily transformed to a diabolical Wild Huntsman. But here also the forces of partial recovery, which we have seen operating in the outcome of internal reform, manifest themselves; the vanquished, and for a time outlawed deity, is, in many cases, subsequently conciliated and given an inferior, and, though hateful, a useful office in the new order. Sometimes, indeed, as in the case of the Hindu destroyer Siva, it is found necessary to assign a god, anathematised beyond all power of whitewash, to an equal rank with the most virtuous deity. Political forces and the exigencies of propagandism work many marvels of this kind, which will meet us in the further stages of our investigation.