It is the dissolving of this elaborate supernaturalism, and the growth of a different conception of the spiritual life, which is now going on before our eyes. To measure the essential significance of the change, we need not linger long upon the successive steps by which the mythology expanded and solidified itself. We have seen its germs in the story of Judaism, of Jesus and his immediate successors. The method and nature of its growth may be briefly indicated. We are following only a single thread in the vast web of history. All the threads work in together, but we must be well content if we can trace the general line of one or two. It is the history of the moral ideas which have most directly and closely influenced the life of men, that we are trying to pursue. There was a wonderful embodiment and outshining of such ideas in the life and teaching of Jesus of Nazareth. The truth he taught and lived was in some ways made more applicable and transmissible by his followers, and in some ways lowered. There grew up the society of the Christian church. Gradually it took its place among the important forces of the Roman empire. It won at last the nominal allegiance of the civilized world. Aiding or thwarting it, coloring and changing it, were a thousand influences,--side-currents from other religions and philosophies, social changes, Roman law and tradition, the new life of the barbarians; old ingrained habits of blood and brain; the constant push of primal instincts--hunger and sex; tides of war and trade and industry; slavery and serfdom; strong human personalities, swaying a little the tide that bore them; all the myriad forces that are always at work in history.