“Correspondence” (dang 當) and “Cultivating Perfectness” (Yang Zheng 養正): On the Concept of Perfectness (zheng 正) in the Yijing

“Properness, correctness and uprightness” (zheng 正) refers to a common and significant concept in Chinese philosophy. In Chinese philosophical discourse, zheng embodies moral ideals. To date, scholarly attention has focused on compound concepts incorporating zheng, such as “central and zheng” (zhongzheng 中正), “the position of zheng” (zhengwei 正位), and “make the family in accordance with zheng” (zhengjia 正家), as their research objects. However, the independent philosophical meaning of zheng in the Yijing 易經 remains underexplored. Through etymological research and textual analysis, this study reveals three philosophical dimensions of the Yijing. First, it distinguishes zheng from “in correspondence to” (dang 當). It shows that dang refers to a judgment about physical alignment with time and position in theoretical situations, lacking strong moral force. Second, it argues that zheng in the Yijing originates from a metaphysical concept of a perfect ideal, broadly referring to the ideal perfect way (zheng dao 正道). The Yijing emphasizes the metaphysical level of zheng (in accordance with the perfect way), and possesses zheng as a strong moral binding force for continuing self-improvement. However, zheng does not directly function as the presupposed rationale for moral judgments and choices. Third, it examines the way of cultivating zheng (yang zheng zhi dao 養正之道) as a theory of moral cultivation (gongfu 工夫). This practical path, articulated through the hexagrams Meng 蒙 and Yi 頤, is interpreted as a form of purifying the heart/mind (xin 心) to align with the cosmic heart/mind. The study demonstrates that the moral source and moral cultivation process in the Yijing refers to a theory of “cultivating one’s heart/mind (xin 心) through practice”. It provides a perspective for understanding the moral perfectness, heart/mind and morality in the Yijing.