Seongho Yi Ik’s New Approach to Zhijue 知覺 and Weifa 未發: Stimulation by Western Learning and the Expansion of Confucianism

This paper explores the 18th-century Joseon Confucian scholar Seongho 星湖 Yi Ik’s 李瀷 (1681~1763) theory on philosophical anthropology in the context of Confucianism through his theory of the heart-mind 心論. This study begins by examining which intellectual heritage he innovated, what intellectual resources he used in the process, and how his theories diverged from those of other Joseon Confucian scholars. Through Western learning books, Seongho obtained the rational soul theory and anatomical and physiological knowledge about the brain, based on which he reinterpreted the controversial Neo-Confucian concepts of zhijue 知覺, and the Weifa-Yifa theories 未發已發論. He acknowledged the primacy of the brain, which differs from the general principles of Neo-Confucianism. Seongho did not imbue zhijue itself with moral meaning, but considered the whole process of perception–recognition–judgment as the weifa state. At this point, yifa is determined by whether moral judgments are made. If yifa is the moment of moral judgment, the relationship between weifa and yifa must be regarded as the relationship between the operation of physical perception–cognition and rational judgment–moral practice. In Seongho’s perspective, moral practice is not a process of static cultivation, but the result of active moral determination.