朱子倫理學是理由內在論嗎？

Is Zhu Xi's Ethics a case of Internalism of Reasons?

本文從理由論的角度切入探問朱子倫理學究竟是理由內在論還是外在論。文章首先釐清內在論與外在論的正確意涵，而其中威廉斯的「內在理由理論」與王陽明的「知行合一」說代表著內在論的兩種典型。本文據此主張對朱子倫理學的內在論詮釋並不成立，並接著以牟宗三判定朱子學中的「性理」是「只存有而不活動」為線索，進一步轉換到理由論的脈絡中，從而得出「性理」只是行動的證成理由而非驅動力之源，就此確定朱子倫理學是一種理由外在論，並將之與麥克道爾式外在論作一對比，經此我們更能了解朱子式外在論因為其「格物致知」程序比麥克道爾式外在論更為精緻，從而突顯出朱子倫理學的實踐意涵。

This paper explores whether Zhu Xi's Ethics, viewed from the perspective of theories of reasons, is a case of internalism or externalism of reason. The meaning of internalism and externalism is first clarified. I identify Bernard Williams' Internal Reason Theory and Wang Yangming's Doctrines of the Unity of Moral Knowledge and Action as two paradigms of internalism. Based on the standard of these two paradigms, I argue that Zhu Xi's ethics is not a case of internalism. In this paper, I also apply the result of Mou Zongsan's analysis, namely that the xingli (Nature-Reason) of Zhu's philosophy is ''merely an ontological Being without activity'', onto the context of theories of reason and argue that xingli is a ground of the justification of action rather than a motivational force. Thus, Zhu Xi's ethics represents a version of externalism. Finally, in comparison with John McDowell's externalism, Zhu Xi's procedure of ''Investigating Things and Extending Knowledge'' proves to be more sophisticated in so far as it is a theory of moral practice.