The Taoist religion was founded by Lao-Tse who lived from 604 to 531 BC and was a contemporary of Confucius. Taoism was started as a theory of philosophy and psychology, but later developed into a religion about 440 BC when it was adapted as a state religion in China. A well-known Taoist belief is the popular Yin (dark side) and Yang (light side), which symbolize pairs of opposites that are seen throughout the universe. The photomicrograph above illustrates gold metal, one of five parts of the sky in Taoist beliefs: water, fire, wood, metal, and earth.