Ji is a key category in the philosophy of Wang Chuan -shan. For him, ji firstly functions as a relationship characterized by identity or similarity (xiang -ji), difference (fen -ji), and interactivity (jiao -ji) at the same time. We can find in Heidegger some similar ideas in his discussion about Innigkeit. Ji is originally ji of heaven and human, from which Chuan - shan systematically explores heaven, human and ji. It is starting from ji that he develops his doctrines on exphcitness and implicitness, the transformation of qi, human nature, human emotion, poetry and language.