Ideas from theoretical computer science continue to have an important influence on areas of philosophy and linguistics. The papers contained in this volume by some of the most influential computer scientists, linguists, logicians and philosophers of today cover subjects such as channel theory, presupposition and constraints, the modeling of discourse, and belief. The contributors include: Jon Barwise, who shows how the ideas of channel theory fit in with non-monotonic logic; Jelle Gerbrandy shows how ideas from dynamic logic can be used to study the notion of common knowledge among groups of agents; Wiebe van der Hoek and Maarten de Rijke provide ideas from theoretical computer science to a more philosophical area, belief revision; Rohit Parikh proposes a solution to one of the problems of belief revision; Paul Skokowski discusses Fred Dretske's theory of content; and Thomas Ede Zimmermann discusses the notions of discourse referent and information states.