證立道德規範性：康德式建構論之嘗試

Abstract

在這篇論文裡，我主張，柯思嘉的康德式建構論能證立道德規範性。首先，我論證，實在論者禁不起她的批評，即他們要嘛無理地拒絕回答規範性問題，要嘛因困宥於自己的規範概念觀而無法說明道德法則為何對我們有規範力。再者，我論證，柯思嘉的構成論能顯示「類行動者」不可能是實踐推理者，所以我們沒有必要回答「我們為何有理由行動？」這個無意義的問題。但是，她的構成論會因無法把道德法則指認為行動的構成原則、因無法解決保留壞行動的可能性所衍生的麻煩，終究無法建立道德法則的規範性。最後，我論證，柯思嘉的先驗論證能顯示道德法則確實約束著所有理性行動者。在回應幾個關鍵的反對意見後，根據本文對理由的公共性的理解和柯思嘉的行動哲學，我構作了一個版本的私有理由論證去鞏固先驗論證的結論：看重所有理性行動者是行動的可能性條件，而行動是我們不可逃避的任務。

In this thesis, I claim that Christine Korsgaard’s Kantian constructivism can justify moral normativity. First, I argue that her criticisms of moral realism are convincing in that moral realists either unreasonably refuse to answer the normative question or fail to explicate why morality has normative force for us due to their conception of normative concepts. Second, I defend that Korsgaard’s constitutivism can confirm that it is impossible for a “shmagent” to be a practical reasoner, and, as a result, the question of “Why do I have reasons to act?” is meaningless. However, her constitutivism can neither identify moral law with the constitutive principle of acting nor cope with the trouble derived from her attempt to leave room for bad action. Therefore, her establishment of moral normativity by means of the constitutivist approach fails. Last, I demonstrate that Korsgaard’s transcendental argument can show that moral law binds all rational agents. Upon addressing some crucial objections, I construct a version of the private reason argument based on my understanding of the publicity of reasons and Korsgaard’s philosophy of action in order to consolidate the conclusion of the transcendental argument: valuing all rational agents is the condition of the possibility of acting, and acting is our, as human beings, inescapable task.