Abstract
The chapter holds great importance in understanding the fundamental aspect of disease occurrence, for it contains key concepts of disease of Naegyeong medicine. For this reason, prominent doctors from Jang Gyeong-ak(張景岳) of Ming to Lee Gyujun (李奎晙) of late Josun have based their Yang Gi-centered medical theories on this chapter. However, doctors such as Ju Jinhyeong(朱震亨) who have stressed the importance of Eum, also used the contents of this chapter to support their perspective on disease, which means that the main voice of this chapter is still unclear. Based on the previous chapter, it is valid to say that uses the Eum-Yang Body-Function Perspective(陰陽體用觀) to establish the fundamentals of life and parallels the uniqueness of each kind of Gi, Eum and Yang, in leading Gi activity in mankind. This philosophy based on the uniqueness of the activity of Eum/Yang Gi expands its target from human to disease in general, becoming actualized as a theory of external/internal body-function perspective. Cultivation methods based on this uniqueness is also being suggested.