摘要
道德的理由是道德哲學的核心問題。懷疑論者可能會質疑，當道德與利益發生衝突時，人還有非得遵守道德的理由嗎？除此之外，道德的成敗也會受到運氣所影響，不像一般所以為的那麼穩固。那麼我們還有理由要有道德嗎？我在這篇論文裡要回應懷疑論者會提出的這兩個挑戰。我要論證人要有道德的證成理由，不在於能夠獲得利益，而在於行為者的意圖本身。我同意懷疑論者在第一個批評上占有優勢，道德與利益確實無法調和。但是如果我們考慮到人是什麼樣的存有者，我們其實還是有理由要求人要有道德。這個理由就是行為者的意圖。而且，即使在運氣的影響下，意圖仍是人要有道德最穩固的證成理由。 在考慮到人實際上是如何掌握應然規範時，需要適當的道德心理學模型。透過本文中所採取的「雙重歷程模式」，可以發現人們在提出道德判斷的時候，包含了個人內在思索以及社會互動兩個方面。我論證了意圖能夠在這兩方面都被當成為證成人應該要有道德的理由。意圖不只解釋了手段目的之間的關係，更是行為者行動時的決定性考量。而且，正因為行為者是有意圖去做這件事，我們可以說意圖是道德行動的內在理由。另一方面，意圖還有客觀的一面。個人會透過社會文化脈絡所建立的基模去辨識、指認行為者的意圖。但成功辨識意圖需要滿足客觀性的要求，包括具有公開性、真實性，並且要與他人共享同一個脈絡。因此，意圖確實可作為要求人要有道德的外在理由。而且，意圖的內容雖然會受到運氣影響，但是行為者總是把意圖當作證成理由。因此，在道德運氣的影響之下，意圖仍會是最為穩固的理由。
並列摘要
The question “Why be moral?” has long been a debate in moral philosophy. Skeptics have attempted to undermine the foundation of morality by arguing that morality cannot be reconciled with self-interests, and that the solidity of morality is jeopardized by luck. I contend that their first challenge is well held. Nevertheless, if we look deeper into the understanding of what kind of normative beings we are, we will find that the solidest ground of why being moral just lies within our intention to be good. To argue for this position, I develop a psychological model of moral judgment. As the model shows, the intention of the agent justifies being moral both in introspection and social interaction. On introspecting, agents take their intentions to be the decisive factor in prompting their actions. And on social interacting, people are inculcated to praise or to blame others’ deeds by identifying their intentions within the cultural contexts. Moral norms are thus done and abided not as alien things but as our nature. Appreciating intentions in this way, I shall conclude that we can confidently ward off skeptics’ challenges on why being moral.