做為康德道德哲學最後一本主要的著作，《道德底形上學》一書長期以來一直受到康德研究者們的忽視。許多論者們認為，〈法權論〉做為《道德底形上學》一書中的第一部份，其中的許多觀點與康德道德哲學中的理念並不一致。然而，在本論文中，筆者即試圖捍衛〈法權論〉的道德地位，以及《道德底形上學》一書的重要性。是故，本論文有兩個主要的論點：第一，康德的〈法權論〉並不會與其道德哲學理念產生衝突，相對的，法權的法則必須由定言令式演繹而來，而法權的系統本身也未違反自律的原則；第二，《道德底形上學》一書扮演了「道德義務學」及「道德實踐學」的角色，從而與《道德底形上學之基礎》及《實踐理性批判》共同構成康德道德哲學系統中不可或缺的重要部份。 / As the last major work of Kant’s morality, the Metaphysics of Morals has long been neglected in Kantian literatures. Many Scholars argue that the Rechtslehre, or Doctrine of Right, as the first part of Metaphysics of Morals, is not consistent with Kant’s moral theory. This research intends to defend the moral status of Rechtslehre and the importance of Metaphysics of Morals in Kant’s moral philosophy. There are two main arguments - firstly, Rechtslehre does not conflict with Kant’s moral theory; instead, the laws of Right should be derived from categorical imperative, and the system of Right does not contradict to the principle of autonomy. Secondly, the Metaphysics of Morals can be regarded as the “doctrine of moral duties” and the “doctrine of practical morality”, and, together with the Groundwork of the Metaphysics of Morals and the Critique of Practical Reason, constitutes an essential part in Kant’s moral philosophy.