A Davidsonian Approach to Weakness of Will and Practical Rationality

• Main Authors: Ya-Ting Chang, 張雅婷
• Other Authors: Chin-Mu Yang
• Format: Others
• Language: en_US
• Published: 2018
• Online Access: http://ndltd.ncl.edu.tw/handle/jw3ubs

博士 === 國立臺灣大學 === 哲學研究所 === 106 === This dissertation concerns two main questions about weakness of will. The first question is: “To what extent is weakness of will possible?”. The second question is: “Must weakness of will be practically irrational?”. This dissertation is thus divided into two parts, corresponding to these two questions. These two questions did not emerge until the publication of Donald Davidson’s influential paper “How is Weakness of the Will Possible?”, in which Davidson argues for two theses. Firstly, he argues that weakness of will is possible because it is possible to act intentionally against one’s all things considered evaluative judgment. Secondly, he argues that weakness of will is a paradigm of practical irrationality. The aforementioned two questions are raised by the critics of Davidson as challenges to these two theses. However, Davidson has never directly offered full responses to the challenges. This dissertation thus aims to offer a complete reply on behalf of Davidson by constructing a Davidsonian approach. The approach is Davidsonian because I will stick to Davidson’s main theses regarding weakness of will, intentional action, and practical rationality, while my arguments may appeal to resources found in recent two decades. In Chapter 1, I give an overview of Davidson’s causal theory of action and how Davidson amends it to cope with the possibility of weakness of will. The aim of this chapter is to lay sufficient groundwork for discussions in the following chapters. Chapter 2 and 3 are devoted to answering the first question. In Chapter 2, I reconstruct a Davidsonian theory of evaluative judgment in order to defend judgment internalism in virtue of resources found in Davidson’s investigation of the basic relation between evaluation and language. I focus on the question about why strict akrasia is impossible in Chapter 3. In Chapter 4 and 5 I then take up the issue about whether weakness of will is paradigmatically irrational. In Chapter 4, I defend the Davidsonian position that it must be irrational in virtue of a study of practical reasons. In Chapter 5, I scrutinize several theories of practical reason and argue that only the Davidsonian approach can offer satisfactory explanation to the practical irrationality of weakness of will. Discussions in this dissertation are based on four intuitive and widely accepted assumptions. First of all, I assume the standard conception of intentional action, the view that an intentional action is an action done for a reason. Secondly, I assume that a weak-willed action is an intentional action. Thirdly, I assume that weakness of will is must be practically irrational. My last assumption is that reasons for action are grounded on practical rationality. I conclude that if we accept these four assumptions altogether, we must accept the Davidsonian view that a practical reason must play two different roles in order to explain the irrationality of weakness of will—that it serves as a reason that explains the intentional dimension of a weak-willed action and that it serves as a cause that explains the irrational dimension of it.