 The "Genii" Chapter argues that these dual souls cause illness and death.All men, wise or foolish, know that their bodies contain ethereal as well as gross breaths, and that when some of them quit the body, illness ensues; when they all leave him, a man dies.In the former case, the magicians have amulets for restraining them; in the latter case, "The Rites" [i.e., "Yili"] provide ceremonials for summoning them back.