本文通過研究羅欽順（1465－1547）、王廷相（1474－1544）、劉宗周（1578－1645）三大明代哲學家的氣論，探討整體宋明氣論的哲學意義，定位此系統在儒家道德哲學中是否可以成立。羅欽順的理氣論並未離開朱熹（1130－1200）的框架，他是以「理氣一物」解決朱子理氣二元的問題；王廷相的學說是真正的氣論，且他的氣有陷於物質性的嫌疑；劉宗周的氣並非形而下，而是形而上的氣，他的氣論是為一種「心氣流行」的型態。本文由上述研究得出結論，即氣論體系從形而下的氣中是無法尋到道德之源的，從形而下論氣，必定會陷於道德動力不足，以及道德主體性無法挺立的問題。

This article explores the philosophical meaning of qi 氣 in Neo-Confucianism through an analysis of the positions advanced by Luo Qinshun 羅欽順, Wang Tingxiang 王廷相 and Liu Zongzhou 劉宗周. It moreover discusses whether their theories of qi can provide a foundation for Confucian moral philosophy. First, it is argued here that Luo Qinshun did not discard Zhu Xi's 朱熹system, and that he advanced the idea that ＂principle and qi are united＂ (理氣一物) to solve the problem of Zhu Xi's principle-qi dualism (理氣二元). Second, Wang Tingxiang's philosophy is identified as a qi-centered discourse (氣本論) as his conception of qi tends toward materiality. And third, the article maintains that Liu Zongzhou's notion of qi is not physical but spiritual, and thus his theory of qi is properly classified as one in which ＂qi and mind flow together＂ (心氣流行). Finally, the article concludes that qi cannot serve as the source of morality (道德之源), and that a moral philosophy based in qi would provide insufficient moral motivation (道德動力).