Agent, Epistemology, and AI Satoshi Tojo Japan Advanced Institute of Science and Technology Abstract In this talk, I will show how our knowledge and belief are changed by agent communication. We apply dynamic epistemic logic to subtle differences of the result of agent communication, e.g., what is informed, what is known to each other, and what is aware of for each agent. En route, we discuss the reliability of information source, including the notion of communication channel. Thereafter, we apply the idea to analyze several legal cases, and try to explain the relation between the suspect’s intention, the result, and his/her predictability of causality in them. Copyright © by the paper’s authors. Copying permitted for private and academic purposes. In: T. Ågotnes, B. Liao, Y.N. Wang (eds.): Proceedings of the first Chinese Conference on Logic and Argumentation (CLAR 2016), Hangzhou, China, 2-3 April 2016, published at http://ceur-ws.org 4