In all this advance, moreover, we find that the process illustrated by the changing phases of man's mental attitude toward Nature also holds good of the multifarious acts by which, in what is known as religion, man has sought to realize that attitude in conduct. For, in seeking to adjust himself to the system of Power, man has been forced to conceive of his Pantheon in terms as well of his social arrangements as of the political system under which he happened to be living. The spirit world of a horde of savages could only reflect the indefiniteness and disunion of the nomads whose imagination it satisfied. But as the household made its appearance, as a definite social structure arose, and the straggling tribes began to be united into nations, the gods themselves took on the characters of an analogous transformation. The divine selfishness--the "_remota ab nostris rebus_"--long ago satirized by the poet Lucretius, obviously correlated with the attitude of man toward man, just as naturally gave way, with the growth of the social sympathies, to the thought of that more active concern in human affairs which is one of the salient characters of the later phases of monotheism. The original indifference of Deity toward ethical issues--a widespread feature of the earlier religious conceptions--could not but pass away with the moral stagnation of the ancient communities out of which it had arisen. So the comparatively new thought of a God definitely identified in his aims and activities with the cause of moral reform is no less obviously a result of the new attitude of man himself toward problems of social improvement; while the persistence with which, in human thought, morals remain associated with religion sufficiently illustrates the extent to which man's view of each has been determined by the self-knowledge which underlies his attitude toward both. Note also, finally, the manifest relation in which our human thought regarding mind and body has always stood toward conceptions of a world-soul, and then the dependence of man's view of the relation of God to the world upon the knowledge of his own planet and of its place in the universe. For as long as our ancestor held the old geocentric theory of the cosmos--regarded the heavens as a set of spheres revolving around a flat earth--the thought of a deity outside the world related to it as a mechanician might be to a cunningly devised piece of clockwork which he had brought into existence, was inevitable. But when the geographical discoveries of the fifteenth century co-operated with the revelations of Galilei to secure the final triumph of the Copernican over the Ptolemaic theory of the world-order, the ancient view of Deity as external to his creation gave place to the essentially modern conception of his immanence.