In the existing body of relevant literature, the different types of moral extension in Mencius’s thought are not clearly differentiated. The purpose of this paper is to show that at least four types of moral extension can be found in Mencius’s thought. First, as is well known, the idea of kuochong 擴充 in Mencius’s thought is that one should extend one’s moral attitude or reaction, such as ce yin zhi xin 惻隱之心, to a broader range of people. Ce yin zhi xin is arguably a moral attitude or reaction towards another person in distress. Mencius argues that such a moral attitude should be expanded to everyone, not solely the single individual in need right now. Second, another type of moral extension is in fact what has wielded more influence in the development of Confucian thought in history: the extension from family to nation. This is distinguishable from kuochong as the expanded attitude is not a purely moral one, but rather an attitude applied initially to blood relations. Third, there is yet another type of moral extension in Mencius’s thought: the diffusion of moral attitudes or actions among different people.
This type is different from the first two types because it has to do with the expansion of the number of people sharing a certain kind of moral attitude or action. Fourth, in his understanding of Mencius, the neo-Confucian Zhu Xi 朱熹 would not be too concerned about the difference between the first type and the second type, which are equally related to the extension of a certain kind of attitude, either ce yin zhi xin or a familial attitude, since he understands both the two types equally in terms of the expansion of ren xin 人心 (the human mind) as such. What Zhu Xi regards as Mencius’s can be understood as the fourth type of moral extension in Mencius’s thought. This paper aims to explore the differences among the above four types, which have not been carefully differentiated in the literature.