Confucian classics in the Southern and Northern Dynasties were divided into two schools: the Southern School and the Northern School. Xue Nan was greatly influenced by metaphysics, which emphasized rhetoric over classics. Beixue is less influenced by metaphysics, excludes Laozi and Zhuangzi, and has a simple style of study. Both southern studies and northern studies advocate righteousness and sparseness, which is quite different from the Confucian classics in the Han Dynasty. The Tang Dynasty ended the separatist regime for hundreds of years after the Han Dynasty and re-established a "unified" feudal empire.