The Neo-Confucian writings of Bangye Yu Hyeong-won, the pioneer of Shilhak, did not remain, and he himself confessed his conversion from a ‘Qi centered view’ to 'Shilli theory', resulting in a variety of interpretations, making the whole aspect of his Neo-Confucian philosophy difficult to figure out. From that time on, as interpreted in his conversion from ‘anti Zhuzi Studies’ to ‘Zhuzi Studies’, he has been recognized as a Juri-theorist with a Li-centered thinking. Nevertheless, many scholars who paid attention to Yu's (...) 'The Theory of Governing Society' evaluated him as a reality-oriented Qi-theorist and experientialist. In this article, through analyzing the content and character of his Shilli theory expressed by Yu himself, and exploring the content, inclination degree, motive and purpose of the conversion he confessed at the age of 37, I examine whether his confession really meant a turn to Juri. I point out that even if he recognized Li's substance and developed Shilli theory, which emphasized Li’s independence and Superintendence Character, he still did not give up 'Qiwaiwuli' and 'Qizhili' and maintained a reality-oriented perspective that focuses on things and practice. I also point out that his Shilli theory has a light inclination that just adds reinforcement of the essential nature to the existence that is already firmly established in his philosophy. The trigger or purpose of the turn to Shilli theory was to secure absolute moral standards that could not be solved by Qi-centered theory, and to lay the cornerstone of his lifelong work, Bangyesurok, on the absolute principle of Tianli. Through this, I develop the argument that his Shilli theory was not a conversion to Juri. (shrink)