Context-Dependent Epistemic Logic : A Formal System

• Main Authors: Yuan-Ho Yao, 姚元和
• Other Authors: Wen-Fang Wang
• Format: Others
• Language: en_US
• Published: 2016
• Online Access: http://ndltd.ncl.edu.tw/handle/44636904816737288348

碩士 === 國立陽明大學 === 心智哲學研究所 === 104 === The main aim of this paper is to give a formal characterization of context, and to define what knowing a proposition in a specific context is. To keep knowledge closure principles and to satisfy intuitions in relevant alternatives theories simultaneously, the knowing operators are given tags in this system. There are two kinds of knowledge operators Km, Kc and a semi-knowledge operator Kc-. Kc phi means that the subject knows that phi in context c. Km phi means that knowing phi in the minimum context of phi. If a context c doesn't contain the minimum context of phi, we can only have semi-knowledge Kc- phi of phi in such context. A model of context-dependent epistemic logic is a 5-tuple, which contains a function C assigning value to each context. This system has PC and T axioms for all contexts. The K axiom is valid if all premises are in the same context. There are also frames for KK axiom for a fixed context or the minimum context. There is also some applications for context-dependent epistemic logic. I will give a solution to the paradox of the skepticism about the external world. Then I will provide some possible solutions to other epistemic paradoxes, like Fitch's paradox of knowability.