We live in 'knowledge societies' and work in 'knowledge economies', but accounts of social change treat knowledge as homogeneous and neutral. While knowledge should be central to educational research, it focuses on processes of knowing and condemns studies of knowledge as essentialist. This book unfolds a sophisticated theoretical framework for analysing knowledge practices: Legitimation Code Theory or 'LCT'. By extending and integrating the influential approaches of Pierre Bourdieu and Basil Bernstein, LCT offers a practical means for overcoming knowledge-blindness without succumbing to essentialism or relativism. Through detailed studies of pressing issues in education, the book sets out the multi-dimensional conceptual toolkit of LCT and shows how it can be used in research. Chapters introduce concepts by exploring topics across the disciplinary and institutional maps of education: -how to enable cumulative learning at school and university -the unfounded popularity of 'student-centred learning' and constructivism -the rise and demise of British cultural studies in higher education -the positive role of canons -proclaimed 'revolutions' in social science -the 'two cultures' debate between science and humanities -how to build cumulative knowledge in research -the unpopularity of school Music -how current debates in economics and physics are creating major schisms in those fields. LCT is a rapidly growing approach to the study of education, knowledge and practice, and this landmark book is the first to systematically set out key aspects of this theory. It offers an explanatory framework for empirical research, applicable to a wide range of practices and social fields, and will be essential reading for all serious students and scholars of education and sociology.