如果從工夫論觀點詮釋心性論與理氣論，我必須強調將會得到這樣的詮釋結果：心與氣本具性或理，是能實現其性或理的實現主體，即道德實踐主體，此是一種道德的執行者；性或理是創生道德的道德之理，必須依氣而實現，此為一種道德的立法者，同時為道德實踐的根據。人通過修養工夫而變化氣質，心與性、氣與理能夠關聯地合一而成道德生命，成為所謂「道德主體」。如此的朱子道德實踐哲學成為「關聯合一的自律道德」形態。;The main focus of this thesis is to study Zhu-xi’s moral philosophy. According to traditional Confucianism, the aim of Zhu-xi’s moral philosophy is to become a sage. In Zhu-xi’s theory, everyone, before being a sage, must keep doing the practice of cultivating himself or herself. Even if the agent has become a sage, he or she still has to keep practicing to maintain or ensure the rightness of his/her act. The approach of this thesis is to regard Zhu-xi’s moral cultivation theory as the ground to interpret his Li-Qi theory（理氣論） and Xin-Xing theory（心性論）. I believe this different approach is helpful for us to understand the practical meaning of Zhu-xi’s moral philosophy.
There are two premises of Zhu-xi’s moral cultivation theory. First, Xin and Qi can affect the actualization of moral commands are both practical subjects. Second, the Xin and Qi practical subjects, Xin and Qi, are easily influenced and limited by human desire, and under the influence and limitation, the practical subjects won’t act in accordance with the moral commands. Due to these two premises, Zhu-xi emphasized that for agents, only through moral practice to cultivate themselves, they can overcome the seducement of human desire, and after the accomplishment of moral practice including cultivation they could purify moral mind and finally become a sage. Zhu-xi’s theory of moral cultivation is constructed of two parts, which are “investigation of reason to the utmost”(Qiong-li, 窮理)and “respectfulness”(Ju-jing, 居敬). The function of Qiong-li(窮理), also called “Ko-wu chih-chih(格物致知, attaining knowledge through investigation of things and matters)”, and its goal(not the final end) is to understand the moral laws and transform the understanding into true knowledge(Chen-chih, 真知). The function of Ju-jing(居敬) is to cultivate the practical subject, Xin, and transform our human desire before we act so that we will act morally and actualize our moral personality as a sage. Zhu-xi claimed that agents can purified their mind to follow the moral commands through Qiong-li(窮理) and Ju-jing(居敬).
According to my moral cultivation interpretative approach, regarding moral cultivation as the primordial element to re-interpret Zhu-xi’s Xin-Xing theory and Li-Qi theory, I must emphasis that the result and the argument are, first, “Xin houses Li(心本具理)” and “Qi houses Li(氣本具理)”. Hence, we have reason to say that Xin together with Qi is a moral agent which could have sufficient capacity to carry out the moral commands. Second, Xing and Li have moral creativity, thus, they are the basis of moral practice. Agent can transform his heat/mind or consciousness from normality to morality through moral cultivation, and through the cultivation, Xin and Xing(as well as Li and Qi) can be rendered identical in the sense of practical unity of agent and principle in relatedness within one body. Third, If the last two points could be justified, Xin and Qi will constitute us as a “moral subject”, and the agent will become a “moral agent”. Therefore, the Zhu-xi’s moral philosophy could be classified as a kind autonomous theory in the sense of unity of Xin and Xing in practical relatedness, or for short, “related identical autonomy”.