朱熹受二程觀點的影響，認定《中庸》為「道統之傳」的本文，並指出《中庸》是「十六字心傳」之展開。本文以朱熹《中庸章句》及《中庸章句序》為主要文獻依據，分別解析了「心」、「中」的系統與朱熹「道統」構建之密切關係。從哲學構建的層面上看，朱熹多層次、多方面規定了「心」的涵義，「心」為「道統」之構建提供了認識論上的保證；又以「中庸」、「中和」為「中」的主體範疇，「中」為「道統」之構建提供了本體論、心性論上的支援。從現實的層面看，朱熹指出，「心」、「中」範疇又體現在日用倫常中並最終將之落實在「天理」「人欲」上，這從道德和實踐上提供了最基礎的體「道」的方法。最後，筆者以余英時「道學—道統」之辨為切入點，以《中庸章句序》為文獻依據，指出「道學」的主體內容是內聖之學，「道學」重在「術」。「道統」重在「道」之「傳」，是「道學」之外化，體現的是儒學的「正統」史。

Zhu Xi was influenced by er cheng (i.e. Cheng Hao & Cheng Yi); he regarded The Doctrine of the Mean as the text of “Confucian Orthodoxy” and as the unfoldment of his “Sixteen-word Mind-to-Mind Instruction”. Based on Zhu Xi’s Commentary on The Doctrine of the Mean and Preface to the Book of Commentary on The Doctrine of the Mean, this paper analyses the close relationship between the system of “Mind” and “Zhong” and Zhu Xi’s construction of “Confucian Orthodoxy”. From the perspective of philosophical construction, Zhu Xi defined “Mind” as multifaceted and having multi-layered meanings, which provided the epistemological guarantee for his view that “mind” was a construct of “Confucian Orthodoxy”. Moreover, using “Zhongyong” (i.e. middle way, balance) and “Zhonghe” (i.e. harmony) as the main subject categories of “Zhong” (i.e. bent neither one way or another), Zhu Xi provided ontological and temperamental support for the view that “Zhong” was also a construct of Confucian Orthodoxy. From a realistic point of view, Zhu Xi maintained that categories of “Mind” and “Zhong” were embodied in our daily moral principles and ultimately implemented in the “heavenly principles” and “human desires”, which provided the most basic way of learning “Dao” at both ethical and practical levels. In the end, the author takes Yu Yingshi’s “Daoxue—Confucian Orthodoxy” debate as a starting point to argue that the main content of “the Confucian studies of ethics” is the study of inner sanctification. “Daoxue” focuses on “theory”, whereas “Confucian orthodoxy” focuses on the inheritance of orthodoxy, which can be seen as the externalisation of the Confucian studies of ethics and part of the “orthodox” history of Confucianism.