The Korean Neo-Confucianism of Yi Toegye and Yi Yulgok (Part 98)
The Four and the Seven are aroused feelings pertaining to the physical human nature (represented by i and ki combined) that includes its original goodness (represented by i only), just as the moon on the water reflects the original moon in the sky. Kobong argues that the Four-Seven relationship can be expressed in terms of the moonlight on the water that represents the physical human nature: “The Four represent especially the bright side (the moonlight on the water), while the Seven represent both bright bright and dark sides (the moonlight on the water).” In other words, the Four are good feelings (bright moonlight), and the Seven Emotions include both good feelings (bright moonlight) and bad feelings (dark moonlight). This corresponds to Kobong’s initial theory that the Seven, the totality of feelings, include the Four as its “subset” of good feelings and that both the Four and the Seven pertain to the physical human nature. The reality of human nature is one, just as the reality of the Seven neither have two different sources (i and ki) nor belong to two separate human natures (the original and the physical). According to Kobong, Toegye’s theory of “alternate manifestation” incorrectly points to the different origins of the Four and the Seven, the Four representing the bright side that came from “another source of light” independent of the moonlight. To emphasise the Four-Seven relationship in the context of inseparability and continuum, Kobong concludes by reiterating his fundamental points: the Four and the Seven pertain to one realm of feelings; they do not have two independent sources; and there is only one concrete reality of goodness including the goodness of the Four and the Goodness of the harmonised Seven.
How did Toegye respond to these points of Kobong’s Four-Seven thesis? I 1952 he responded with a short letter. In this last reply to Kobong, Toegye did not wish to revise his hobal Four-Seven thesis claiming that he had already clarified it in his previous letter to Kobong. For him, so much had been gained through the debate that it was no longer necessary to push the debate further for complete agreement. One problem are, on which he finally agreed with Kobong, is that “the goodness of the Four is the same as of human nature, he also accepted Kobong’s view that the physical human is never another nature independent of the original human nature. But he rejected Kobong’s view that both the Four and the Seven are issued from ki.