Abstract: Through Zhou Dunyi’s interpretation proposed in his Discussion of the Diagram of the Supreme Polarity, the Supreme Polarity(Taiji)came to be viewed as the highest category of Neo-Confucianism. However, the idea that “Without polarity and yet the Supreme Polarity, the Supreme Polarity in activity generates Yang” provoked extensive debates. In his essay “Discriminating Perversity”, in Ming Dynasty Neo-Confucian Cao Duan focused on the statement that “The Supreme Polarity is spontaneously able to be active and still” and raised questions concerning whether principle is “living” or “dead”, the relationship between principle and Qi, etc., which influenced not only the development of the relationship between principle and Qi in the Ming Dynasty, but also the thought of Korean philosopher Yi Toegye, giving rise to debates in Korea concerning principle, Qi, the four inklings and the seven emotions over a period of three hundred years. This paper evaluates the validity of the content of “Discriminating Perversity” by assessing: 1)Whether or not there is any contradiction between the interpretation in Zhu Xi’s Explanation of the Meaning of the Supreme Polarity referred to in “Discriminating Perversity” and that in his Recorded Sayings; 2)Whether or not Zhu Xi’s explanation was in accordance with Zhou Dunyi’s original meaning in his Discussion of the Diagram of the Supreme Polarity; 3)Whether or not Cao Duan fully understood Zhu Xi’s ideas, and if not, what causes lay behind his misunderstanding. In addition, the paper further assesses the influence of Cao Duan’s philosophy on Yi Toegye and Neo-Confucianism in the Ming Dynasty, so as to provided a reasone assessment of the historical significance of “Discriminating Perversity.”

Key words: the relationship between principle and Qi, whether principle is “living” or “dead”, Cao Duan, Discriminating Perversity