With the successful development of East Asian countries, world-wide interest on their culture has been increased. This paper aims to compare as social ethics the Enlightenment as a root of modern Western thoughts with the Confucianism in the East. Social Ethics is the reference of social behaviors and the models of desirable behaviors to attain the ideal society based on the understandings on the society and human beings. As a result, epistemology on individual, society, and their relationship is the basis of social ethics. Enlightenment thinkers such as Hobbes, Locke, and Kant faced difficulties establishing the moral relationship between individual and society because of their presupposition of the isolated primitive individual. By contrast, Confucianism acknowledges the indivisible wholeness of individual and society. Confrontations between individual and society in the Western thought do not exist. Rather individuals are induced to adapt to multiple social statuses and perform social roles accordingly. Because of their ahistorical presupposition of primitive individuals of unalienable rights, Enlightenment thinkers and modern rationalism reveal problems in defining the proper relationship between the individual and society, while Confucianism successfully provides ethical and behavioral models for social life. Also discussed are the being and oughtness, dualism of reason and sentiment, human existence and time and space, single-minded rationalism, and the intervention of the state and increasing formal rationality.