Abstract
Ki Jeong-jin proposed a distinctive perspective in which the unified li 理 transforms into individual li by itself, and these individual li subsequently become the natures of distinct species. This viewpoint starkly contrasts with the Yulgok school’s theory, which posits that the unified principle differentiates through qi 氣. In response, Jeon Woo critiqued Ki Jeong-jin by adhering to the doctrines of the Yulgok school. According to him, a species’ nature is wholly attributed to the influence of qi. Ki Jeong-jin’s disciple, Jeong Eui-rim, defended his teacher’s doctrine by embracing the organic model. He likened the relationship between Heaven and all things to that of the body and its limbs, contending that it embodies a ‘whole-part’ connection. Just as the parts coalesce to constitute the whole, the whole is omnipresent within the parts; similarly all things come together to form Heaven, and Heaven is omnipresent within all things. Based on this, Jeong Eui-rim concluded that all things ‘originally existed’ alongside Heaven, and further postulated that the li of all things originated from this ‘original existence.’ Consequently, his contention is not that the unified li differentiates into the li of all things through qi but that the li of all things inherently existed and evolved into the natures of various species.