Abstract

This article has the purpose of examining the commentation that Sung-ho Yi Ik and Da-san Jung Yak-yong developed of Sa-chil Debate (사칠논쟁) Which was a philosophical debate in Chosun Dynasty. Sa-chil Debate began from Toe-gye Yi Whang and Ko-bong Gi Dae-sung and soon as a result of Yul-gok Yi Yi and Woo-gae Sung Hon repeating the debate, It appeared as a kind of philosophical theme. After that, Yul-gok and Toe-gye's students formed a kind of school. They also made the debate extended and the theory more sophisticated by criticizing a counterpart's argument on base of ideologizing their teacher's theory. About 200 years after Toe-gye died, Sung-ho Yi Ik was born and after about 250 years, Da-san Jung Yak-yong was born. Both they experienced a western naturalscience and a catholic theory as Silhak Scholars (실학자). Therefore their this kind of interpretation about Sung-li Debate must be offering a deeply interesting investigation to us. In conclusion, Sung-ho advocated Toe-gye's theory at all, adding more explanation to it and Da-san evaluated all of Toe-gye's and Yul-gok's theory to be right because their theories have a unique logicality of making a sense. Sung-ho stood on a Shilhak view point gave up a organic cosmology ofSung-li theory which has a continuity to cosmology and moral theory, arguing Sa-chil-Li bal-Yil-lo Theory (四七理發一路說) by understanding Sa-chil Debate based on only moral perspective. Even though Da-san also said Yang-si Theory (兩是論) that both their theories are all right, he argued that Toe-gye's theory is much more important in the aspect of moral practice owing to his religious opinion by a catholic affect. By the way, Sung-ho supplemented and explained Toe-gye's theory, but he had not a sufficient logic and was not objective because of his leaning into advocating Toe-gye's theory much further. Da-san had an advantage of evaluating both Toe-gye's and Yul-gok's theory to be all right, but came to argue an insufficient philosophy on account of its simplicity.