The I Ching ( Book of Change ) is considered the oldest of the Chinese classics, and has throughout Chinese history commanded unsurpassed prestige and popularity. Containing several layers of text and given numerous levels of interpretation, the I Ching has been venerated for more than three thousand years as an oracle of fortune, a guide to success, and a source of wisdom. The underlying theme of the text is change, and how this fundamental force influences all aspects of life—from business and politics to personal relationships. In this translation, previously published as The Tao of Organization, the root text is supported by commentary by Cheng Yi. A distinguished scholar and teacher of the eleventh century, Cheng Yi is regarded as one of the greatest sociological thinkers of Song-dynasty China. He conveys a fundamentally forward-thinking attitude in his treatment of the text, based on the belief that since change is an inexorable law of the universe encompassing everything in the world, great and small, it is better to overtake change than be overtaken by it.