契約論、假設性思考與公共道德的規範性

Contract Theory, Hypothetical Thinking, and the Normativity of Public Morality

假設契約論面臨標準批評：假設契約不是契約，如此，假設契約論不能證成規範實際政治社會的公共道德原則，也不能對實際的人加上有約束力的公共道德義務。本文論說羅爾斯式的假設契約論的方法──原初處境式的假設性思考的方法能適當且合理地回應前述批評。而且，這種假設性思考的方法在實踐規範性有兩面：一是公共道德原則的規範性是客觀的，另一是規範現實的人對於公共道德議題的實踐思慮。如此，假設契約論的方法論也合理說明現實中的人有理由與動機採納這種假設性思考的方法來思考、處理公共道德的困惑與爭論。

Hypothetical contract theory commonly faces the standard objection that because hypothetical contracts are not contracts at all, the theory is both unable to justify the fundamental principles of public morality for actual political societies. Also, it is arguably incapable of imposing obligations of public morality on real people. I shall argue that a Rawlsian type of hypothetical contract theory is capable of providing adequate and reasonable responses to the standard objection, and that the original-position type of hypothetical thinking has two important normative functions for our practical matters. One: it explains how this method of hypothetical thinking produces objective principles of public morality. Two: it provides guidance by giving reasons and motives to comply with the principles of public morality produced by the hypothetical approach.