The I Ching, or Book of Changes, has been one of the two or three most influential books in the Chinese canon. It has been used by people on all levels of society, both as a method of divination and as a source of essential ideas about the nature of heaven, earth, and humankind. During the eleventh and twelfth centuries, Sung dynasty literati turned to it for guidance in their fundamental reworking of the classical traditions. This book...