摘要
何種事物是行動理由（reasons for action）? 行動理由是意欲（desires）和信念（beliefs）嗎？這些關聯到理由的性質之問題在行動哲學中十分重要。理由的心理主義（Psychologism）認為，行動理由是主體的心理狀態（mental states），即意欲的狀態與信念的狀態之結合。理由的事實主義（Factualism）認為行動理由不是心理狀態，而是事實（或即為真的信念）。本文的主要工作是，藉由重構與檢視史密斯（Michael Smith）的心理主義和艾瓦蕾茲（Maria Alvarez）的事實主義之論證，說明這兩種觀點如何了解理由的性質，以及鑒於理由的性質之理解如何去解釋行動中的規範性（normativity）與動機（motivation）。此外，我們將指出這兩種理論各自所具有的難題。具體而言，一方面我們將透過重構艾瓦蕾茲對於心理主義的反駁，來顯示心理主義所存在的難題。另一方面，我們也將指出，事實主義本身具有的原則也會導致一些困難，包括她對於假信念（false belief）處理方案會產生不一致。
關鍵字：行動理由、意欲、信念、事實、事實主義、心理主義
行動理由、意欲、信念、事實、事實主義、心理主義
Abstract
What kinds of things are reasons for action? Are reasons for action desires and beliefs? The questions concerned with the nature of reasons are essential in the philosophy of action. One conception of reasons for action is Psychologism which says reasons for action are agents’ mental states that are combinations of a state of desiring and a state of believing. Another conception is Factualism which says reasons for action are not mental states, but facts (true beliefs). First, in the essay, I shall examine and restructure both Michael Smith’s arguments on defending Psychologism and Maria Alvarez’s arguments on defending Factualism. With the examinations, I shall illustrate how Smith and Alvarez account for the nature of reasons for action and how they explain the normativity and motivation in action through their own understanding of reasons. Second, I shall point out the problems of both sides. For this purpose, I restructure Alvarez’s objections to Psychologism to present the difficulties of Psychologism and argue that the underlying principles of Factualism may also engender some problems, including the inconsistency in terms of her solution to the case of false belief.
Keywords：reasons for action, desire, belief, facts, Psychologism, Factualism Narrative, Tradition
MacIntyre, Virtue, Practice, Narrative, Tradition