本文對於船山論孟子學的「心」義做一解說，特別鎖定在心與性之間的關連，蓋因為船山此文是中年的作品，故於架構上都是以朱子學為主，而朱子學以「性即理」（此概念從伊川而來）與「心統性情」兩大架構以詮釋孟子。而船山對於「心統性情」的講法特別鍾情，而面對楊龜山的一席「正人心」之說，有所不滿，視之為無法概括孟子全書之心義。蓋因為孟子言心，不皆需正之，因為孟子言心，有求放心、盡心等，心中有性，性善故心亦善，此時的心則不用正之。此乃統性情之心本亦正也，不需待外以正之。此船山依著朱子的格物致知、誠意正心的架構以詮釋孟子。然他對於朱子學有所繼承，亦有所修正，吾人此文便對於此中，三、四層的意思（孟子一層、朱子的孟子學第二層，船山的孟子學又是一層，其中龜山的講法亦可視為一層），做一解說。

This paper elaborates the interpretation of ”mind” in Mencius, as suggested by Wang Chuanshan, and focuses on the connection between ”mind” and ”nature”. The reason for it is that Wang's commentary was completed in his middle age, and thus, the framework of his thought was based on the interpretation of Zhu Xi. Zhu Xi interprets Mencius by two main aspects, ”nature is reasoning” and ”mind dominates disposition”. Wang preferred that ”the mind dominates disposition”, while was dissatisfied with ”direction of human heart” of Yang Guishan. Wang suggested that Yang's statement cannot complete the meaning of Mencius. Mind suggested by Mencius is not necessarily directed. Mencius' Mind refers to relaxation and devotion. When nature is in mind, nature and mind both will be righteous; it is not necessary to direct the mind. Mind which dominates the disposition is righteous. Wang interpreted Mencius in according to ”study of the nature of things” and ”righteous mind” of Zhu Xi. However, he followed and modified the learning of Zhu Xi. This paper explains the issue in four aspects (the first is Mencius, the second is Zhu Xi's interpretations of Mencius, the third is the interpretations of Mencius by Wang, and the statement of Yang is the fourth aspect).