論穆爾（G.E.Moore）的「非自然主義倫理學」

On G.E. Moore's Non-naturalism

本文以穆爾的《倫理學原理》為主要研究對象，旨在剖析穆爾對傳統規範倫理學中的自然主義倫理學的批評與他所提出的非自然主義倫理學觀點。首先，穆爾釐清何謂自然主義倫理學，然後再指出自然主義倫理學的種類及其所犯之謬誤。例如：效益主義與快樂論等傳統倫理學家，欲將倫理學上的「善」概念等同「自然現象」穆爾稱之是犯了「自然主義的謬誤」。因為「善」是一單純、簡單、不能也無法被定義的概念。再者，形而上的倫理學也同自然主義倫理學一樣地犯了「善」不能被定義的相同錯誤，他舉康德的倫理原則為例：因為康德將「善」定義為「被意志的」，但穆爾認為「被意志的」並無法跟「這件事物是善的」這個命題劃上等號。總之，善是單純概念，自然主義倫理學要給善下定義是無法實現的，穆爾以「開放問題的論證」來作為反駁——無論誰給「善」下任何定義，總是會成為一個開放沒有結果的問題，因為所給的定義不僅不是真正的答案，並且還會造成無限的問句延續下去。

This essay is based on G E. Moore's Principia Ethica, and is aimed at investigating how Moore shows the critiques of naturalistic Ethics and illustrates his point of view about Non-naturalistic Ethics. Moore explains what naturalistic Ethics is. Secondly, Moore points out naturalistic ethical philosophers, for instance, traditional ethical philosophers like Utilitarianistic and Hedonistic philosophers, who want to definite ethical 'good' as 'natural things' will make a mistake, what Moore called 'naturalistic fallacy', because ethical 'good' is, according to Moore, a pure, simple and indefinable concept. It is the same fault as Kant's Metaphysical ethics does, because it was wholly in the wrong to define 'good' as 'be willed'. It is not right to define 'good' as something or anything. To sum up, we can not define 'good' in any case, and, if you do so, Moore will refute with 'open question argument'. In short, whoever wants to define 'good' will leave these questions open. For these are not the exact answers, and the questions will bring about endless circular arguments.