Animism is another tap-root of savage superstition. As the child sees life in the doll, so the savage sees life in every object, animate or inanimate, which comes in contact with him, and affects his existence. Animals, and even stocks and stones, are supposed to have souls, and who knows that these may not be the souls of departed ancestors, and have some mysterious power of helping or of hurting him? In any case the safer plan is to propitiate them by worship and sacrifice. From these rude beginnings we see nations as they advance in civilization rising to higher conceptions, developing their ghosts into gods, and confining their operations to the greater phenomena of Nature, such as the sky, the earth, the sea, the sun, the stars, storms, seasons, thunder, and the like. And by degrees the unity of Nature begins to be felt by the higher minds; priestly castes are established who have leisure for meditation; ideas are transmitted from generation to generation; and the vague and primitive Nature worship passes into the phase of philosophical and scientific religion. The popular rites and superstitions linger on with the mass of the population, but an inner circle of hereditary priests refines and elevates them, and begins to ask for a solution of the great problems of the universe; what it means, and how it was created; the mystery of good and evil; man's origin, future life and destiny; and all the questions which, down to the present day, are asked though never answered by the higher minds of the higher races of civilized man. In this stage of religious development metaphysical speculations occupy a foremost place. Priests of Heliopolis, Magi of Eridhu and of Ur, reasoned like Christian fathers and Milton's devils of "Fate, free-will, foreknowledge absolute," and like them "Found no end, in wandering mazes lost."