The present volume contains a selection of papers presented at the Fifth Conference on Collective Intentionality held at the University of Helsinki August 31 to September 2, 2006 and two additional contributions. The common aim of the papers is to explore the structure of shared intentional attitudes, and to explain how they underlie the social, cultural and institutional world. The contributions to this volume explore the phenomenology of sharedness, the concept of sharedness, and also various aspects of the structure of collective intentionality in general, and of the intricate relations between sharedness and normativity in particular. Concepts of Sharedness shows how rich and lively the philosophical research focused on the analysis of collective intentionality has become, and will provide further inspiration for future work in this rapidly evolving field.

The aim of this volume is to explore new approaches to the problem of the constitution of the various aspects of sociality and to confront these with received ideas. Therefore many of the contributions to this volume are devoted to a rather holistic and antireductionist conception of social objects, groups, joint actions and collective knowledge. The topics, that are dealt with are: a) the question of the ontological status of social objects and their relation to physical objects, b) collective agency and c) the question whether there can be shared knowledge and shared beliefs - a rather new topic in the discussion of the social aspects of personal life.