The Korean Neo-Confucianism of Yi Toegye and Yi Yulgok (Part 151)
Surely, the Mencian doctrine of human nature demands one’s effort to “seek our lost mind” or to return to the original goodness of human nature. This is part of the reason that Toegye referred to simhak as “the learning of principle” (ihak), “the learning of human nature and principle” (songnihak), and “the learning for sagehood” (songhak) as complementary designations. On the whole, his simhak emphasises “suppressing human desires and preserving Heaven’s principle.” It suggests a way of experiencing Heaven’s principle as moral principles embodied in the Four Beginnings; this is the core of his simhak, which he maintained in his Four-Seven thesis as well as other major writings. In fact, his entire philosophy of self-Seven thesis as well as other major writings. In fact, his entire philosophy of self-cultivation is based on such a theme. It developed especially as a fruitful result of his debate with Kobong.
Toegye’s admiration for the Sung Neo-Confucian Li Tung (Yen-ping, 1088-1163), one of Chu Hsi’s teachers, reveals how seriously he committed himself to the practice of mind cultivation. As revealed in his major works and biographical records, the topic of quite sitting and simhak became an important topic of instruction to his disciples. This conveys the degree of Li Tung’s influence on Toegye. For Li Tung, quite sitting served as a contemplative exercise to help one penetrate into the essence of one’s inner nature. As he told his disciples, what Toegye found useful in Li’s method is a way to experience the mind-in-itself. As he asserts, Li referred to it as a method of “examining the unmanifest mind (mibal) in the state of quietude before the arousal of feelings.” The core of Toegye’s simhak is the self-realisation of it. Unlike Li Tung, however, Toegye argues that such an experience should not preclude an establishment of relation with the mind in its “manifest” state (ibal). In other words, the role of the manifest mind is significant in the whole process of moral self-cultivation: “Only after the practice of quite sitting, can one collect the body and the mind so that moral principles can be united together.” For the practice of simhak, then, the first thing to do is to “collect” the dispersed self according to moral principles; this helps one’s search for the “original substance” (pen-ti) of human nature. In other words, it is a contemplative, spiritual discipline that ought to integrate one’s intellectual insight and moral effort simultaneously. Toegye refers to it as the essence of becoming a sage. For this reason, he consistently maintained the Cheng-Chu idea that principles are inherent in human nature, urging Kobong to accept his view that the Four Beginnings of virtue must be manifest from i.
For Toegye, human nature in itself is identical to Heaven’s principle, the absolutely good and pure reality. From an experiential standpoint of self-cultivation, his theory and practice of simhak emphasise the virtuous and transcendent dimension of i as something to be contemplatively realised and internally cultivated in the mind-and-heart. Toegye’s approach to simhak addresses kyong or “reverential seriousness” as the most important the virtue to be cultivated in quite sitting and mind cultivation. This is the focus of our next inquiry.