本篇論文的主要重點就在於通過亞里斯多德與儒家中庸概念的比較而奠立差別化原理與其形而上學的基礎，在亞里斯多德哲學與儒家哲學裡，「中庸」此概念解釋之為將認識或判斷原理的「中」與實踐原理的「庸」合而成為人生的技術（techne），就儒家哲學而言，「中」和「庸」兩個獨立辭彙的結合把中庸的哲學性意義更為明顯出來，不過在西方的哲學概念中只有「中」，而沒有與「庸」相比的用語，「庸」是哲學的實踐原理。從亞里斯多德的觀點看，「庸」是與「中」隔離的原理，就是相應於習慣化。我要特地從形而上學的、認識論的、倫理學的角度比較亞里斯多德與儒家的中庸概念。第一，從形而上學的觀點比較中庸概念的適用原理與其範圍。亞里斯多德的中庸概念就是限於人而說的，然儒家卻把中庸的含意擴充到宇宙而說之。就是說，天是一種形而上學的原理，代表萬物的根源和倫理的源泉。所以儒家則與亞里斯多德不同，認為中庸是形而上學的原理，也是倫理的原理。第二，從倫理學的觀點比較亞里斯多德和儒家對感情的哲學性態度。依亞里斯多德看，中庸則意指限於與靈魂之非理性的部分有關的品性之德（virtue），就表示適切且妥當地發揮感情的。儒家針對人的感情說出「喜怒哀樂之未發，謂之中；發而皆中節，謂之和。」亞里斯多德和儒家都指出與非理性的部分有關的中庸。然而儒家則進一步而說通過「誠」與「慎獨」能「致中和，天地位焉；萬物育焉。」「中和」的意含就從倫理的層次擴充到存在論的層次。這是儒家與亞里斯多德有區別的一面。第三，從認識論的觀點探討亞里斯多德的「中的」與儒家的「時中」，同時要檢討對中庸在認識上的難處。所謂中庸就在每一個情況都有不同地表現，因而不容易認識到何者為適切的，對此判斷也難。亞里斯多德與儒家都認為對中庸的認識與判斷是不容易的，但主張為了實踐中庸需要不斷訓練與努力。這一點是兩人相為一致的。

This paper is aimed to find the principles of differentiation and the metaphysical basis by comparing Aristotle’s the Mean with Confucianism’s ZhongYong. These concepts show a very important attitude in the way of life. In Confucianism, the combination of two independent terms, “Zhong” and “Yong,” make the philosophical meaning of the Mean more clearly and abundantly. In the Aristotle’s the Mean, there is no term corresponding to “Yong,” but this aspect of the Mean is explained independently in his virtue ethics. Above all, this study will compare Aristotle’s the Mean with Confucianism’s ZhongYong on the systems of metaphysics, ethics, and epistemology. First, on a metaphysical point of view, Confucianism applies the Mean not only to humans, but also to the whole universe unlike Aristotle. Aristotle also mentions the term “middle (meson)” in his works of natural science. But it relates to “the Mean relative to objects,” not “the Mean relative to us” mentioned in Aristotle’s Nicomachean Ethics. Secondly, on an “ethical” perspective, Aristotle’s the Mean and Confucianism’s ZhongYong have a certain sort of similarity and difference. On the one hand, the Mean and ZhongYong are similar in that they all relate to human emotions. In this case Confucianism use the concept of “ZhongHe” (中和) instead. “He” (和) is the state of harmony. The Mean and ZhongHe implies a state in which feelings can rise appropriately. On the other hand, the Mean and ZhongHe differ in that they have different applicable scopes. Unlike Aristotle, Confucianism’s ZhongHe is also the principle of universal harmony. Thirdly, on an epistemological point of view, both Aristotle and Confucianism claim that the Mean and ZhongYongis not one and the same for all. It is very difficult to recognize exactly what the mean is in each circumstance. Aristotle used the concept of “hitting the mark” (stochastic), and Confucianism used the concept of “acting on proper time” (時中). They argue that it is difficult to conceive the Mean and ZhongYong. In fact, it is hard for us to find the most appropriate feelings and actions, because we can’t consider nor understand everything completely.