What is Ying and Yang?

The early Han dynasty (207 B.C.-9 A.D.) devoted itself to regaining the same level of central government as the Ch’in (221 B.C.-207 B.C.) and the Legalists had so ruthlessly accomplished. This ideology of central government, along with the Legalists’ attempts to standardize Chinese culture and Chinese philosophy, led thinkers of the Han to attempt to unify all the rival schools of Chinese thought and philosophy that had developed over the previous three hundred years.