T'Ai Chi

in Chinese philosophy, the eternal source and cause of all reality.

In the Book of Changes (I Ching), the ancient philosophical text in which the concept is first mentioned, T'ai Chi is the source and union of the two primary aspects of the cosmos, yang (active) and yin (passive). The Neo-Confucian philosophers of the Sung dynasty (&AD; 960–1279) associated T'ai Chi with li (“principle”), the supreme rational principle of the universe. Li engenders ch'i (“vital matter”), which is transformed through the yang and yin modes of development into the Five Elements (wood, earth, fire, metal, and water), which form the basic constituents of the physical universe.