「法律是什麼?」這個問題，是法理論最核心的實質問題。但 是，在這個實質問題的背後，卻隱藏另一個關鍵問題，那就是有關「法理論的本質是什麼?」的方法論爭議。法實證主義者向來主張， 法律本質屬性的辨識與道德無必然關聯，同時也堅決認為，她(他)們的法理論，是一種道德中立的描述性理論。有鑑於此，本文嘗試對法理論本質的方法論議題進行檢討，審視法實證主義者捍衛其描述性立場所提出的兩種論據，亦即「詮釋學觀點」與「間接評價法理論」，是否為妥當可信的論據。故此，本文首先介紹「論述觀點」的方法論爭議，並詳述詮釋學觀點的要當;接著分析「間接評價法理論」的兩項主張，後設理論評價與社會理解命題;最後針對詮釋學觀點與社會理解命題，分別進行批判性的反省與檢討，進而主張描述性法理論的方法論論述，無法妥當證立其法理論為道德中立的理論。

The question about "What is law" is the central substantive issue of legal theory. Nevertheless, there is another critical issue behind this question, that is, the methodological controversy about "What is the nature of legal theory". Legal positivists usually argue that the identification of law's essential properties has no necessary connection with morals. They also argue that their legal theory is morally value-free and descriptive. Accordingly, this essay attempts to explore the methodological issue that concerns the nature of legal theory. Two arguments, the argument of hermeneutic viewpoint and the argument of indirectly evaluative legal theory, will be taken into account respectively to examine the plausibility of the positivist c1aimthat legal positivism is a descriptive theory. In this way, the essay first of all articulates the methodological. controversy about the "viewpoint of discourse" and the main theme of the hermeneutic point of view. Then, It further takes into account the "meta-theoretic evaluation" thesis and the "social understanding" thesis defended by indirectly evaluative legal theory. Finally, some critical reflections upon the incoherence of the above two theses are provided to dispute the methodological discourse that tries to justify descriptive legal theory as a morally value-free theory of law.