You have noticed that everything an Indian does is in a circle, and that is because the Power of the World always works in circles, and everything tries to be round. The sky is round, and I have heard that the earth is round like a ball, and so are all the stars. The wind, in its greatest power, whirls. Birds make their nests in circles, for theirs is the same religion as ours. Even seasons form a great circle in their changing, and always come back again to where they were. The life of man is a circle from childhood to childhood, and so it is in everything where power moves.
-- Black Elk