明清之際儒學有股一元化的傾向，強調理與氣、心性與情等是一不是二，其極端者 甚至要把一切宋明儒學的概念分解取消，悉統而一之。本文旨在解釋此一元化傾 向，即其出現、形成、思想涵義及評價。必須指出，恰當理解這股思潮不但有助我 們更好地詮釋個別儒者的思想，如王陽明、湛甘泉、羅整菴、劉蕺山與黃梨洲等， 更可充分說明儒學在明清之際所經歷的義理轉型或曰典範轉移。本文除首節引言 外，第二節析論宋明儒學的一元化思想的五個不同意義，由此以見一元化傾向實乃 過度發揮一元化思想的某些意義所造成的思想混淆。第三節仔細考察一元化傾向的 形成過成，最後指出其如何促成明清之際儒學的義理轉型。

Some thinkers during the Ming-Qing transitional period tended towards monistic thought, which emphasized that li (principle) and qi (material force), xin (heart/mind) and qing (sentiment), and xing (nature) and qing are one rather than two. There were even those proposing extreme arguments that all the conceptual distinctions made by Song-Ming Confucian scholars could be eliminated and all pairs of concepts could be unified. This paper aims to illustrate this kind of thought in terms of its appearance, formation, theoretical meanings, and evaluation. An appropriate understanding of this kind of thought can help not only better interpret the philosophies of individual Confucian scholars, including Wang Yangming, Zhan Ganquan, Luo Zheng’an, Liu Jishan, and Huang Lizhou, but also explain the transformation of Confucianism (a paradigm shift) during the Ming-Qing transitional period. Section one of this paper is an introduction. Section two analyses five different meanings of the thought of oneness in Song-Ming Confucianism and points out that monistic thought is indeed a fault generated by an overemphasis of some meanings of the thought of oneness. Section three investigates the appearance and formation of monistic thought and the final section looks at its influence on the transformation of Confucianism.