孟子心性論在學界是一歷經千錘百鍊的課題，但是如果我們只關注文字理論的面向，將某些「無法被文字解釋」的部分加以化約，如此亦將損及其心性學本體論的豐富意涵。孟子的氣論以「善養」吾浩然之「氣」為核心，開展出一條較為具象——以「氣」統合吾「人」與「世界」的論述系統；本文嘗試將氣論與心性論系統並列比較，並反思其利弊。透過「心」理論特徵、「氣」的文本分析，以及兩者內在關連性的探討，進而分析心性論與氣論兩組工夫進路屬性之差異，希能於傳統觀點中尋得更具時代性的孟學深義。

Mengzi’s theory of mind and nature has been a well-tried academic topic. However, if we are only concerned with the literary dimensions of “mind and nature” and reduce the literally unexplainable parts, the rich meanings of Mengzi’s ontological doctrine of “mind and nature” would be compromised Mengzi’s theory of qi is focused on the cultivation of one’s expansive qi, developing a more concrete framework on how “qi” unifies the “man” with the “world.” This article is meant to compare the theory of qi and the doctrine of mind and nature, while reviewing their strengths and weaknesses. Through the theoretical attributes of “mind,” the textual analysis of “qi” and the exploration about the connections in between, we will further analyze the differences between the approach of the doctrine about mind and nature and the one of the theory of qi in wishes to find a more contemporary meaning among all the traditional perspectives.