On the Giants (12-13)

Some souls, therefore, have descended into bodies, and others have not thought worthy to approach any one of the portions of the earth; and these, when hallowed and surrounded by the ministrations of the father, the Creator has been accustomed to employ, as hand-maidens and servants in the administration of mortal affairs.

And they having descended into the body as into a river, at one time are carried away and swallowed up by the voracity of a most violent whirlpool; and, at another time, striving with all their power to resist its impetuosity, they at first swim on the top of it, and afterwards fly back to the place from which they started.