?This eminently readable book does a great job on two fronts. It opens up the issues of joint intentionality, group agency, and collective responsibility, introducing readers to the many perspectives found in this rapidly emerging field, and it offers a fine, accessible statement of the distinctive views that the author herself has developed on those issues.? Philip Pettit, Princeton University and the Australian National University ?In this outstanding new book, Deborah Tollefsen analyses group belief and agency while at each stage clearly articulating the relation between groups and individuals. She critically evaluates all the major philosophical theories of group cognition and develops her own novel, integrative framework anchored in our everyday practices of interpreting the actions of groups. Tollefsen?s accessible work has implications for ethics and the law, for psychology and for social theory, effectively bringing philosophy to life.? John Sutton, Macquarie University ?Deborah Tollefsen is well versed in the contemporary philosophical debates about, to put it broadly, the mentality of groups. This book is a thoughtful and clearly written introduction to these debates. Tollefsen also offers her own perspective, one which engages with the notion of mentality itself.? Margaret Gilbert, University of California, Irvine