Socially Extended Epistemology explores the epistemological ramifications of one of the most important research programmes in contemporary cognitive science: distributed cognition. In certain conditions, according to this programme, groups of people can generate distributed cognitive systems that consist of all participating members. This volume brings together a range of distinguished and early career academics, from a variety of different perspectives, to investigate the very idea of socially extended epistemology. They ask, for example: can distributed cognitive systems generate knowledge in a similar way to individuals? And if so, how, if at all, does this kind of knowledge differ from normal, individual knowledge? The first part of the volume examines foundational issues, including from a critical perspective. The second part of the volume turns to applications of this idea, and the new theoretical directions that it might take us. These include the ethical ramifications of socially extended epistemology, its societal impact, and its import for emerging digital technologies.