After studying the Four Books, the students were about to move on to the Five Classics. First among them was the I Ching, the most famous and revered work of Chinese philosophy, and also the hardest for foreigners to understand. What astonished Nick was that the Eight Trigrams diagram had supposedly been discovered on a turtle's back.
The wisdom of the "hexagrams" had always been something ancient Chinese thinkers longed to attain. Confucius was especially fascinated by their mystery and lavished them with praise. He wrote books and expounded doctrines, devoting much of his energy to interpreting the hexagrams, yet even he could not be certain that he fully understood the meaning of every one.
China's theories of the origin of the universe were tangled and complex. Compared with the mythical tales told by the old licentiate, Nick preferred to turn to Daoism. One traditional view held that while a person was alive, two things existed within them: the hun, representing the spirit of the mind, and the po, representing the spirit of the body. Only through the interdependence of yin and yang could all things exist in the world. While a person lived, the two coexisted harmoniously in the body. Upon death, they separated: the hun corresponded to yang, and the po to yin.
Egyptians believed that the soul left the body to wander about, and Chinese people likewise believed that the hun left the body during sleep. Of course, it usually returned, but if it remained away too long, all kinds of abnormalities could arise, along with illness—drowsiness, madness, even death.
A Dutch sinologist living in the southeastern community of Xiamen discovered that people's terror, anxiety, and insomnia were caused by the prolonged separation of the hun from the body. When children became listless, restless, or ill, it