Cheng Hao
In terms of Buddhist metaphysics, Zhou Dunyi influenced the beliefs and teachings of Northern Song-era Confucian scholars such as Cheng Hao and Cheng Yi (who were brothers), and was a major influence for Zhu Xi, one of the leading architects of Neo-Confucianism. They emphasized moral self-cultivation over service to the ruler of the state (healing society's ills from the bottom-up, not the top-down), as opposed to statesmen like Fan Zhongyan or Su Shi, who pursued their agenda to advise the ruler to make the best decisions for the common good of all. The Cheng brothers also taught that the workings of nature and metaphysics could be taught through the principle (li) and the vital energy (qi). The principle of nature could be moral or physical, such as the principle of marriage being moral, while the principle of trees is physical. Yet for principles to exist and function normally, there would have to be substance as well as vital energy. This allowed Song intellectuals to validate the teachings of Mencius on the innate goodness of human nature, while at the same time providing an explanation for human wrongdoing. In essence, the principle underlying a human being is good and benevolent, but vital energy has the potential to go astray and be corrupted, giving rise to selfish impulses and all other negative human traits.