道德義務的第二人稱規範性：基於共同立法作為自我建構之先驗條件的辯護

Abstract

道德義務的「規範性問題（normative question）」問的是：我們能對道德義務被聲稱具有的權威提供什麼樣的證成。本文討論的是當代關於規範性問題的理論中，可視為康德式理論的內部爭論：規範性的來源是第一人稱（first-personal），還是第二人稱（second-personal）的？柯斯嘉（Christine Korsgaard）認為，規範性最終源於理性行動者對自己採取某些觀點並透過選擇實踐身分自我立法；因此規範性來源是第一人稱的，只要行動者會自問「我該如何行動？」，他便具有以義務約束自身的能力。而達沃（Stephen Darwall）則認為道德的規範性來源是第二人稱的⸺來自具有適當權威的他人對行動者提出的要求，在第一人稱的觀點中沒有什麼能讓我們理解並確保道德義務被假定具有的那種能於主體之間相互要求、負責的規範性。然而，第二人稱規範性可能面臨被化約為第一人稱，或從第一人稱觀點而言可選的風險。本文目的在於釐清兩種理論的爭點，並為第二人稱的理論辯護。最終本文主張柯斯嘉的第一人稱規範性必須具有第二人稱的形式，且不能預設自身或任何特定行動者作為該形式的主體。這顯示了道德義務的規範性來源是所有理性行動者之共同立法的構成性條件，因此是第二人稱，而非第一人稱的。

The “normative question” about moral obligations is that how and why their alleged authority over us can ever be justified. The issue discussed in this essay is an internal dispute between Kantians on their theories of normativity: is the source of normativity first-personal or second-personal? Christine Korsgaard argues that normativity is derived ultimately from the rational agent who takes some point of view of himself and self-legislates by adopting some practical identity. Therefore, the source of normativity is first-personal, an agent has the capacity to obligate himself as long as he can ask himself, “How should I act?” On the contrary, Stephen Darwall argues that the source of moral normativity is second-personal, it is derived from the demands and claims addressed by others with legitimate authority over an agent. Nothing from our first-person perspective enables us to understand and justify the alleged normativity of moral obligations that can be mutually addressed between agents and make us responsible to each other. However, second-personal normativity may face the risk of being reduced to first-personal normativity, or being optional from the first-person standpoint. The aim of this essay is to clarify the respective arguments in these two theories and defend the second-person theory. In the end, I argue that only by second-personal form can Korsgaard’s first-personal normativity gain its alleged binding force, and one cannot presuppose a reflecting self or any particular agent as the subject of this form. This means that the source of normativity of moral obligations is a constitutive condition of common legislation among all rational agents, and thus it is second-personal rather than first-personal.