本文首先就朱、王二家對於《繫辭上傳》所云：「一陰一陽之謂道」1的詮解析論二家在本體論中論「陰陽」與「道」的關係，並推衍至「理」、「氣」概念在二家本體論中之意涵及關係，總結出二者理論之異同。在「陰陽」與「道」的關係中，朱熹強調了「道」作為「所以然」、「使之然」的本體義，與現象界的陰陽有本體與現象的區別；在體用關係上，其以「道」為體，以「陰陽」為用，體、用是殊別的，是以朱熹之學，實有判析「道」、「陰陽」為二的涵意，在「理、氣」關係上，亦是析「理」、「氣」為二，而以「理」為本。船山則主張「陰陽」是存在的實體，而「道」作為其運行規律，乃存在於陰陽二氣變化運動中，而非獨立於「陰陽」之外，可謂以「陰陽（氣）」為本，又主張「道器無異體」之說，在「理、氣」關係上，雖主張以「氣」為本，然其最重要的特徵在於「道、器」、「理、氣」的統一而非析別。

Based on Zhu’s and Wang’s interpretations and commentaries of the passage from Xi Ci I, “the successive movement of yin and yang constituting tao,” this article analyzes how they addressed ontologically the relationship between “yin-yang” and “tao,” infers the meanings of “li” and “qi” as well as the relationship between them in their respective ontological doctrines, and then concludes with the similarities and differences between Zhu and Wang. With regards to the relationship between “yin-yang” and “tao,” Zhu emphasized how “tao” as an ontological entity differed from “yin-yang” as a phenomenological entity. Regarding the body-application relationship, Zhu somewhat separated “tao” as the body from “yin-yang” as the application. In terms of the relationship between “li’ and “qi,” Zhu also saw them as two different things, while “qi” was based on “li.” On the other hand, Wang saw “tao” as the law of the movement of “yin-yang,” while the latter is a real entity, that is to say, “tao” is unified with rather than separated from yin-yang (qi). Therefore, regarding the relationship between “li” and “qi,” Wang maintained that “li” was based on “qi.” However, what really characterized Wang was the unity rather than distinction of “tao and qi” and “li and qi.”