本論文的論旨是探討道德兩難這種道德情境的解題困難及其困難的道德或價值根源。首先，我將解題困難分為兩種類型，一種是我們在解決問題的過程中所面臨的解題障礙，另一種則是我們試圖架構問題時所面臨的困難。解題障礙有兩個，一個出現在我們理解問題的階段，稱為道德不確定性，另一個則出現在道德或價值判斷的階段，稱為價值不可共量與不可比較（AIV）。至於另一個類型的解題困難，則是前人研究對道德兩難的各種理解上和解題上的思想錯誤，本論文將之統稱為解題迷思。 在道德不確定性的部分，我指出道德考量正確性的不確定、相關性的不確定以及結果／後果的不確定這三種是造成道德兩難解題困難的道德不確定性類型。透過事例的論證，我發現有兩種情況會在道德理解的階段產生道德不確定性的問題，一種是概念模糊的情況，另一種是因科學或科技的發展而造成的無預期的新問題。從James Wallace的道德世界圖像中，我們知道解決問題就是成功地將舊知識調整為適合解決新問題的新知識。然而，我們的道德資源時而成功地進行調整與解題，時而調整失敗而殘留道德不確定性的問題。根據我的研究，主要的原因在於，當某個道德問題涉及到概念階層的徹底改變時，我們的道德資源就無法調整舊有的資源來整合這些新的現象。James Griffin認為，道德或倫理學的經驗性與社會性特質導致了它在處理跨越道德領域的道德問題時受限於問題視野的不足。最後，這一切導致了道德不確定性成為舊知識、舊思想在面對新的道德情境時，因人類還未發展出完整的新調和架構而處於的一個過渡狀態。 在探討AIV如何及為何造成道德兩難的解題困難的篇章中，我首先分析了價值不可共量（IV）與價值不可比較（ICV）的概念。在IV的部分，我將IV區分為數學意義與理論意義的IV。數學意義的IV的側重點在於否定內在價值判準的存在；而理論意義的IV則是揭示價值之間分屬不同的概念或價值架構。接著我的研究轉到ICV的概念分析，我認為目前西方學界認可的，來自Raz和Chang的兩大ICV定義並沒有把ICV的內涵真正釐清，因此我指出了它們各自的問題之後，提出了我所建議的ICV定義作為我的研究基礎。在第二節裡，我們發現ICV通常涉及不同類型的價值，透過群論與邏輯類型的理論架構，我將類型與其他相關概念的分類規則建立起來，並將上一節對價值比較與價值判準的研究銜接在價值類型的議題，最後得出的研究結果是：相同的類型意味相同的組織原則，也意味相同的價值判準，反之亦然。這就可以初步說明為什麼不同類型的價值與ICV的關係如此密切。最後，我以價值架構論來解釋ICV根源的理論架構，並說明了我們的價值世界如何存在兩個相互獨立的價值架構：道德價值架構與審慎價值架構。這兩大價值架構各自依循不同的組織原則，也因此，它們之間的衝突很難解決。 最後，我重新回到道德兩難論辯的脈絡來考察前人們是如何架構道德兩難這個問題。首先我分析他們各自對道德兩難的定義以及與其它相關概念的關係，接著我也分析了對道德兩難的解題脈絡非常重要的概念：「解決」。從上述的分析中，我發現可以將前人的研究取向區分為兩大解題架構類型，一個是「以原則或價值為中心的解題架構」，另一個則是「以道德行動者為中心的解題架構」。我嘗試以之前的概念架構為研究資源，重新建立這些解題架構的內在部分，也就是從中發現解題架構裡的解題模式、解題條件、解題進路。經由解題架構的剖析，我們發現了隱藏在這些解題架構內的各種思想或預設的錯誤。最後，我把觸角伸入檯面下的解題迷思，這些解題迷思是更加隱晦不明的思想盲點，因為它是我們所習而不察的理解問題與架構問題所依據的前提與假設。這兩種解題迷思引導前人往錯誤的方向去架構道德兩難，也導致道德兩難被貼上不可解決的標籤。 Moral dilemmas are considered to be the most difficult moral situation which we encountered in ordinary life. This thesis aims to examine the perplexity of this situation in details and profound way. Perplexity refers to the problems which prevent us from comprehending and resolving moral dilemmas. My main task in this thesis is to detect the problems and trying to trace back the sources which contribute to these problems. I divide the perplexity of moral dilemmas into two types: one is called the quandaries of resolution which appeared as the signal that moral dilemmas are irresolvable at all. The quandaries of resolution are considered as the main problems of the moral dilemmas. It can also be divided into two parts, namely, moral uncertainty and incommensurability and incomparability of values（AIV）. Another type of the perplexity refers to the ideas or assumptions which we possess without being aware of its wrongfulness or misguidance. These ideas or assumptions are generally called the myths of understanding, they mislead us to the problematic ways while we trying to constitute the framework of resolution. In chapter 2, I try to show that why moral uncertainty is hard to solve in certain ways, and that the source of its difficulty deriving from the change of the conceptual schemes to which we have not yet to prepare well to adjust our sources of understanding. In chapter 3, I construct a new definition of incomparability of values. After examining the connections between value types, incomparability of values and criterion of values, I found that different types of values have their own framework of values which determine their nature of criterion of values. By analyzing these frameworks of values, I conclude that the values which are subordinated to different frameworks, are difficult for us to compare their relative normative weight. If we try to resolve the moral dilemmas through comparing the conflicting values, different types of values will made the task harder or even fail. Finally, I explore the elements in moral dilemmas, and find out that there are two kinds of the frameworks of resolution; one is value-centered framework, while another is agent-centered framework. These frameworks reveal the diversity ways of how we understanding, designing and framing the resolution of moral dilemmas. However, they also manifest how we presupposing some wrong ideas about moral dilemmas which bring out a common belief that moral dilemmas are extremely difficult or even irresolvable. Those myths of thinking are considered to be the deepest sources of the perplexity of moral dilemmas.
