牟宗三先生對「為何道德」的議論初探

「為何道德」(Why be moral?)的問題，是後設倫理學(meta-ethics)的一個主要問題。本文會從英美關於「為何道德」的討論開始，檢視經驗進路的問題及缺憾，而這缺憾又如何逼出形上領域的探討。牟宗三先生認為儒家的道德的形上學，才能貫通形上形下的世界，為道德提供堅實的基礎。他以儒家的本心本性說明道德的普遍必然性，以至使人「無可逃於天地之間」。本文除了闡述此點外，更指出道德哲學與形上學在何種意義下，有着緊密的關聯。

The question of "Why Be Moral" is an important issue in meta-ethics. In this article I will start with the examination of the empirical approach to this question and its difficulties. I will then show that how the discussion is inevitably led to the sphere of metaphysics. Mou Tsung-san argued that only the Moral Metaphysics of Confucianism can provide a substantial ground for morality. He explained the universality and necessity of morals by the Confucian idea of original heart-mind and original nature. Apart from elaborating Mou's view, I also expound that in what sense there is a close relation between moral philosophy and metaphysics.