A matter of trust: Dynamic attitudes in epistemic logic

While propositional attitudes-like knowledge and belief-capture an agent's opinion about a particular piece of information, dynamic attitudes, as understood in this dissertation, capture an agent's opinion about a particular source of information, more precisely: they represent the agent's assessment of (or opinion about) the reliability (or trustworthiness) of the source. The project of this dissertation is to study the latter notion from a general qualitative vantage point. The proposal of the thesis is to formally represent assessments of reliability by means of operations on information states: dynamic attitudes are encoded as strategies for belief change, capturing how an agent plans to "change her mind" once receiving a particular piece of information from a particular (type of) source. In this way, the dissertation establishes a connection to the rich existing literature on information dynamics, which has been a major focus of attention in belief revision theory, dynamic epistemic logic and dynamic semantics. The main focus of the work presented here is a study of the interplay between dynamic attitudes and the more well-known propositional attitudes.