效益、效益，多少罪惡假汝之名而行---論效益主義與日常道德規則的衝突

Abstract

許多效益主義者的批評者認為只要殺人、偷竊、搶劫或是違背諾言可以促進最大幸福的實現，那麼這些行為都是效益主義者所允許的，這似乎顯得效益主義不夠尊重日常道德規則。這種批判如果成立，對於效益主義而言，自然是一大威脅。在筆者的研究中，筆者將論證，這種對於效益主義的批判乃是一種誤解，效益主義事實上有理論上的資源可以解釋日常道德規則。為了支持這個論點，筆者將效益主義區分為三種不同的版本: 行為效益主義、規則效益主義以及黑爾的雙層理論。 行為效益主義認為行為者在道德上有義務P進幸福。雖然這是一個很崇高的理想，但這也表示只要某些令人憎惡的行為有助於最大幸福的實現，那麼行為效益主義就會要求行為者去做那些行為。簡而言之，行為效益主義有可能違反日常道德規則。相對而言，規則效益主義者認為行為者在任何情況下都必須遵守日常道德規則，雖然採取這種觀點似乎對規則效益主義者有利，但事實上它也有它的缺陷。畢竟，為了維護日常道德規則，而捨棄對於最大幸福的追求，這似乎流於對規則的盲目崇拜，而且也似乎有違道德促進幸福的宗旨。黑爾的雙層理論可以彌補規則效益主義的缺陷。其理論主張，雖然日常道德規則在大多數的情況下都應被行為者所遵守，但這些規則絕非如規則效益者所宣稱，具有一種神聖而不可侵犯的地位。筆者的研究將探討黑爾的雙層理論要如何與行為效益主義及規則效益主義兩者區分，並且探討雙層理論要如何解釋日常道德規範。本研究的原創性在於對黑爾的雙層理論提出一個新的闡釋，以回應長久以來效益主義所遭受到的批判。

Many critics of utilitarianism claim that it would condone killing, stealing, robbing, and breaking promises whenever these actions are found to be expedient for the promotion of maximal happiness. It seems that utilitarianism does not take our commonsensical moral rules seriously enough. This charge is a serious one that threatens the plausibility of utilitarianism. In my research, I will argue that utilitarianism, contrary to its critics’ (mis)conception, has theoretical resources to take full account of commonsensical moral rules. I defend this thesis by distinguishing three types of utilitarianism: act-utilitarianism, rule-utilitarianism, and Hare’s two-level theory. Act-utilitarianism maintains that the agent is morally required to promote happiness. While it has a noble goal to achieve, it may indeed prescribe abhorrent actions whenever they are necessary for the realization of maximal happiness. In short, it may run afoul of commonsensical moral rules. In contrast, rule-utilitarianism insists that the commonsensical moral rules must be strictly followed by all means. Although this position might seem to be a merit to rule-utilitarianism, it has its flipside. Abandoning the pursuit of the maximal happiness for the preservation of commonsensical moral rules, it smacks of rule-worship and seems to contradict the welfare-promoting purpose of morality. Hare’s two level theory serves as a remedy for the defect of rule-utilitarianism. It maintains that while the commonsensical moral rules must be adhered to in most situations, they are never sacred and inviolable in a way rule-utilitarianism claims them to be. My research investigates how Hare’s two-level theory is to be distinguished from both act-utilitarianism and rule-utilitarianism and how it can fully accommodate commonsensical moral rules. It is original research in the sense that a new perspective on Hare’s two-level theory is provided to offer a solution to a long-standing problem that plagues utilitarianism.