The discourses of Yojo (looking after one's health) in Japan from the eighteenth century to the middle of the nineteenth century often required having one's "Yoku" (desire) under control. The purpose of this paper is to clarify the episteme of the body in the discourses of Yojo, from the Kaibara Ekken Yojokun (1713) to Mizuno Takusai Yojoben Kohen (1851), examining the concept of "Yoku". The episteme of the body in this paper was the mechanism of perception and idea of the body. Three procedures were employed for the purpose of this paper. The first was to confirm the relation between "Qi" (substance or energy) and body, and to examine the growth of the concept of "Qi" in the discourses of Yojo. The second was to clarify the relation between economic activity in urban society in that era and having one's Yoku under control in Yojo. The last was to clarify the relation of the concept of "Yoku" and the inside of the body and self-consciousness. The main results can be summarized as follows. The main points of Yojo were filling and surrounding the body with "Qi". Yojo, considered that "Yoku" and "Gaija" (the course of a disease) reduced and congested "Qi", which existed in the body. The increase of having one's "Yoku" under control in the discourses of Yojo from the eighteenth century to the middle of the nineteenth century strengthened the connection between "Qi" and "Yoku". This brought about the importance of the control of one's "Yoku". The background to this increasing tendency toward having one's "Yoku" under control was the development of the urban monetary economy. A consumption-based, affluent culture had been found desirable, and Yojo claimed control over it. In the discourses of Yojo, there was "Yoku" within one's own body. Self-consciousness was the result of having one's "Yoku" under control. "Yoku" in the discourses of Yojo was a conceptual apparatus that established the connection between "Qi" and moral acts, and a continual care of oneself as a practical moral being.
