Neo-Confucianism in the Sung Dynasty, particularly Chu Hsi's doctrine, enjoyed its great popularity in the Chosan Dynasty in Korea. Some of Chu His's opinions and theories have deeply discussed in Korean Confucianism, and make his doctrine different from what is in China. The debate on the "Four Clues and Seven Emotions" touched on here is regarded as its most important topic. In this article, important points taken from the letters written by Yi T'oegue and Ki Kobong talking about such a debate are fully explained. It is hoped that the explanation will have a definite understanding of where the theory is about their debate. This article is also intended to contrast the meaning of the four-seven debate with contemporary research achievements in Chu-Hsi thought.
