Procedural Information and the Dynamics of Belief

The point of departure for modern epistemic and doxastic logic is Jaakko Hintikka’s seminal book Knowledge and Belief: An Introduction to the Logic of the Two Notions (1962)1. While Hintikka’s project sparked some discussion among mainstream epistemologists (especially regarding the “KK Principle”: Does knowing something imply that one knows that one knows it?2), much of the work on epistemic and doxastic logic was taken over by game theorists (Aumann, 1999) and computer scientists (Fagin et al., 1995) in the 1990s3. As a result, the field of Epistemic Logic developed into an interdisciplinary area no longer immersed only in the traditional questions of mainstream epistemology. Much recent work focuses on explicating epistemic issues in, for example, game theory (Brandenburger, 2007), economics (Samuelson, 2004), computer security (Halpern and Pucella, 2003; Ramanujam and Suresh, 2005), distributed and multiagent systems (Halpern and Moses, 1990; van der Hoek and Wooldridge, 2003), and even the social sciences (Parikh, 2002; Gintis, 2009). This focus on different “application” areas has pushed the analysis beyond the basic epistemic logic of Hintikka (1962) and Aumann (1999) (representing an agent’s “hard” information) to “softer” informational attitudes that may be revised. Recent work by epistemic logicians has identified and analyzed a rich repertoire of informational attitudes. Examples that have been subjected to a logical analysis include different flavors of belief, such as “strong” and “safe” belief (van Benthem, 2007; Baltag and Smets, 2006); “syntactic” notions, such