重估氣質之性，是明儒對朱子學的質疑。楊東明（晉菴，1548～1624）身為北方王門的代表者之一，對義理之性與氣質之關係，是承繼陽明「性即氣，氣即性」的基本立場。但在論述型態上，則有別於王畿（龍溪，1498～1583）、鄒守益（東廓，1491～1562）等人，採取氣化宇宙論的表述方式，主張「義理須在氣上始見」。相較王門諸子，他正面肯定「氣質之性」，認為正是「性」字提點出「氣質」之存有意義。人稟氣質而存，其目的是為了實現人性中當然不容已的「義理」而活。又由於「義理」非「氣質」不見，故主張「氣質之外無性」。由於他在論述型態上，與王廷相（浚川，1474～1544）等明代氣學家相似。因此有學者將他歸為氣學陣營。本文於此有不同看法。故在闡明晉菴「氣質之外無性」之要旨後，嘗試辨析他與明代氣學家之異。

The re-evaluation of pure human nature in relation to temperament was a question raised by Confucian scholars in the Ming dynasty in response to Zhu Xi's studies. Yang Tongming (Jin-an, 1548-1624), a representative of the Northern Yangming school, inherited Wang Yangming's basic stance on the relationship between pure human nature and temperament, arguing that "pure human nature is "Qi," and "Qi" is pure human nature." However, Yang Tongming's adoption of "Qi"-based cosmology and his advocacy that "argumentation must first be seen in 'Qi,'" set his discussion apart from that of Wang Ji (Lung-hsi, 1498-1583), Zou Shouyi (Dong-kuo, 1491-1562), and others. Compared with many scholars of the Yangming school, Yang Tongming positively affirmed the pure human nature of temperament and believed it was pure human nature that revealed the meaning of existence of temperament. He argued that human beings exist according to their temperament, and their purpose is to realize the necessary "moral and value (yili)" within pure human nature. Since moral and value can only be perceived through temperament, Yang Tongming asserted that "there is no pure human nature outside of temperament." Given that his exposition is similar to that of Wang Tingxang (Jun-chuan,1474- 1544) and the scholars of the school of "Qi" in the Ming dynasty, some researchers have classified Yang Tongming as a scholar of the school of "Qi." The author of this paper disagrees with this classification and intends to identify the differences between Yang Tongming and the scholars of school of "Qi" in the Ming dynasty by elucidating Yang Tongming's thesis that "there is no pure human nature other than temperament."