Abstract: This article primarily examines the proposition of “xing yi” (“性一”，same nature) discourse and its efficacy,while also reconsidering and reinterpreting the textual issues in the chapter on “The Nature of Sages” in Cheng Zhi Wen Zhi(《成之闻之》).This manuscript should be studied in conjunction with the manuscript Xing Zi Ming Chu(《性自命出》),as both support the doctrine of “xing yi,” in contrast to the theory of self-cultivation.The proposition of “xing yi” is based on this contrast.Moreover,the proposition of “xing yi” has its metaphysical foundation,which is the idea of “Nature emerging from Mandate” or “The mandate of heaven is what is called nature”.The premise of this is the exclusion of quantitative differences in the endowment of qi,considering only the qualitative aspects of innate endowments.The central focus of “xing yi” lies in its efficacy,and there are two modes of manifestation: one is contrasting,as seen in the “Nature–Teaching” doctrine in Xing Zi Ming Chu and Cheng Zhi Wen Zhi,and the other is sequential,as seen in the human nature theories of Gaozi,Mencius,and Xunzi.The former involves significant tension,while the latter dissolves the “xing yi” doctrine within their judgments of good and evil in human nature.The transition of the efficacy of the “xing yi” doctrine from contrast to sequential conformity marks a significant advancement in intellectual history.Both the “xing yi” and “close nature” doctrines may have been advocated by Confucius,with the latter serving as a step toward the former,while the former represents a breakthrough over the latter.The former is the formal doctrine,while the latter is a provisional explanation.The essence of both doctrines is the same,as they both point to moral cultivation and self-reflection in the practice of self-cultivation.