The Cheng–Zhu school (Chinese: 程朱理學; pinyin: Chéng Zhū lǐxué), is one of the major philosophical schools of Neo-Confucianism, based on the ideas of the Neo-Confucian philosophers Cheng Yi, Cheng Hao, and Zhu Xi.
He believed that the Dao (Chinese: 道; pinyin: dào; lit.
In the Neo-Confucian formulation, li in itself is pure and almost-perfect, but with the addition of qi, base emotions and conflicts arise.
Human nature is originally good, the Neo-Confucians argued (following Mencius), but not pure unless action is taken to purify it.
Zhu Xi believed in gewu (Chinese: 格物; pinyin: géwù), the 'investigation of things', essentially an academic form of observational science, based on the idea that li lies within the world.