The term Er’yan often appears in LiZhi’s writings. It is a concept that reveals his unique philosophy. Er’yan is the old vocabulary in the Book of Poems and the Mean, but until LiZhi’s time, its meaning had always been recognized as a trivial and meaningless language of common people. LiZhi linked this to his Childlike Mind theory and made the meaning into the true words of ordinary people. Eventually, called Er’yan got the meaning of truthful hearted language stood on the opposite side of hypocrisy, and in politics, it’s being interpreted as the means of Sage’s politic that reminiscent of today’s democracy. From the perspective of LiZhi’s Childlike Mind theory, Er’yan was discussed on both sides that are the moral as body and the political action as use. By the theory of Er’yan, LiZhi has also laid the foundation for the Holy Spirit theory and the Common Literature in the late Ming dynasty.