This book centres on a broadened view of complexity that will enrich engagement with complexity in the social sciences. The key idea is to employ complexity theory to develop a holistic account of practice, agency and expertise. In doing so, the book acknowledges and builds upon the relational character of reductive accounts. It draws upon recent theoretical work on complexity, emergence and relationality to develop a novel account of practice, agency and expertise in and for workplaces. Biological, psychological and social aspects of these are integrated. This novel account overcomes problems in current views of practice, agency and expertise, which suffer from reductive, or fragmented, analyses, based upon individuals, groups, or networks. In retrieving the experiential richness of human activity often esteemed as the basis of generative and creative life this book shows how complexity both emerges from, and is, a non-reductive feature of, human experience, especially in daily work. an ambitiously wide-ranging volume, questioning the key tenets of respected approaches .. and offering .. novel accounts, which draw on features of complexity thinking. But they go further than any of us in their argument that: whatever reductive moves are made, they flow from holistic accounts of relationality which have already affectively engaged the purposes of a co-present group. This is the intellectual contribution that is built consistently and persuasively across the chapters. Professor Emerita Anne Edwards, Oxford University "Hager and Beckett have written a book that will challenge more commonly held notions of agency, practice, skills, and learning. Centering their argument on complexity theory or, as they prefer, complexity thinking, Hager and Beckett argue that it is through relations that we raise questions about, gather data from, and make working sense of the complexity that surrounds us. Groups then, particularly small groups, hold and implement agentive power. And what the authors call co-present groupsones in which holistic relationality occurs socially, and affectively in distinctive placesdraw us closer to each other, and harness our normativity by enabling negotiability and reason-giving. If your field of study involves anything remotely sociocultural in nature or if you are just interested in the complex ways we engage as humans with our worlds, you should find a place for this book in your library." Bob Fecho, Teachers College, Columbia University, New York NY, USA.