A Formal Account of Self-Knowledge and Action

Abstract

In this paper, we propos_e a formal theory of knowledge and action that accommodates indexical knowledge and reflects the dependence of action upon it. The model-theoretic semantics of belief given characterizes an agent's belief state not only in terms of the ways the world might be if his beliefs are true, but also in terms of how the world must look from his perspective. We then propose a specification of the conditions under which an agent is able to achieve a goal by doing an action that does not require the agent to know in an absolute sense who he is or what time it is. Finally, we show through an example how actions can be characterized in an agent-relative way within the theory, so as to avoid requiring the agent to know which objects are acted upon, and how such a characterization can be used to prove that an agent is able to achieve a goal by doing an action if he knows certain facts.