In this essay, the sense of gantong 感通 is taken as a vital clue, and a line of interpretation is established that brings the complex meanings of ren and its various forms of writing into a coherent unity. The interpretation here identifies one of the oldest meanings of ren as gantong: open and affective comportment with spiritual, human, and natural beings in the surrounding world. The origin of ren lies in the ancient rites of ancestral worship that featured the spiritual surrogates (shi 尸) who served as the intermediary for the communication and interaction (gantong) between dead ancestors and living descendents, between heavenly spirits and human beings. While this use of ren as gantong did not start with Confucius, what distinguished the Confucian understanding of ren was the shift of priority from the way of heaven to the way of the human, from the divination and intuition of godly injunctions to care and compassion among different individuals in the human community. Openness and sincerity of heart became the central meaning of ren in Confucian teachings and the root of Confucian moral cultivation, which can be best described as a gradual process of person opening instead of person making.