In defining man, pre-Qin Confucianists first starts a discussion about the differences between man and beast. This is the Differences between Beast and Man. For the Differences between Beast and Man, pre-Qin Confucianists never analyze the differences between man and other animals from an ontological viewpoint through pure factual elements. Rather, they distinguish between man and beast from a normative viewpoint. The distinction between man and beast leads to a logical conclusion that, as man is fundamentally superior to beast, 'Man is a different species from beast'. Understanding man in this way is common to all pre-Qin Confucianists, although there are some differences. After examining what humane is based on the difference between man and beast, pre-Qin Confucianists discuss the issue of human perfection with a further step. That is a question of the Differences between Sage and Selfhood with respect to how a sage is different from and the same as an ordinary person. Although Confucius states that he cannot set himself up as a sage, Mencius and Xunzi suggest a viewpoint of the Homogeneity of Sage and Selfhood that a sage and an ordinary person (or selfhood) are basically equal. This point is to highlight the universal equality of Sage and Selfhood in which a sage is no different from an ordinary person and any ordinary person can reach the level of a sage through efforts. Thus, pre-Qin Confucianists view man as a being between beast and sage, and, based on that, discuss the issue. In this context, this study intents to analyze the pre-Qin Confucianists' philosophical debate on man based on the viewpoints of the Differences between Beast and Man and the Differences between Sage and Selfhood.