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 the seasons form a great circle in their changing, and
always come back again to where they were. The life of a man
is a circle from childhood to childhood, and so it is in everything
where power moves.
(Oglala Sioux holy man)