This edited volume of chapters from leading international authors aims to make explicit the extent to which social work turns on competing social science theories and philosophical commitments. Each chapter is a short interpretative analysis that outlines the contributions made to social work by contemporary theorists, theories or perspectives. The book outlines key theoretical and methodological ideas that have been formed within social work and shows how these have been adopted and critiqued by social workers. A select bibliography of each thinker or approach is provided at the end of each chapter as a learning aid for students. A glossary is also given at the end of each chapter that defines key concepts, with links to theorists and perspectives and a timeline of influential journal articles and books is also provided. To 'think social work' is to engage with and against contemporary and past theorists and theoretical concepts. This volume sees theorizing as essential engagement, to counter the new state of pragmatics in a post-9/11 world that encograges a severing of thought from practice. To this end, the book reflects on ways in which major theorists, theories and perspectives in social work may be brought together to take social work beyond familiar domains and prevent slippage into pragmatic quiescence.