Liu Zongyuan
Li Yuxi was involved in a philosophical debate with his fellow literati, the poets Han Yu and Liu Zongyuan, concerning the duality of heaven (the sky, and by extension the natural world or God) and earth (the world of man). Han Yu, as a Confucian, regarded Heaven as paramount, whereas Liu Zongyuan regarded them as separate spheres. Lu Yuxi’s view, expressed in an essay called the Tianlun Shu (Tiānlùn shū 天論書), was that heaven and earth (i.e. nature and man) interacted to some degree. Heaven sometimes predominated over earth, and earth sometimes predominated over heaven.