Zhu Xi, a Neo-Confucianist from the Southern Song dynasty, preferred Wei Ying-wu's poems over Tao Yuan-ming's due to the Theory of Mind-Nature. He believed that the mind and natural principles should be in harmony, but saw a split between Moral-mind and human-mind, causing tension. This led to the need to eliminate harmful desires and focus on natural principles. Zhu Xi admired Wei Ying-wu's ascetic poems, which contrasted with his own impulsive ones. In Zhu Xi's poems, the subject and object were in a unity of opposites relationship, with control and being controlled.