This is the first systematic philosophical and conceptual study of the notion of a social practice. Raimo Tuomela shows how social practices (for example customs and traditions) are "building blocks of society," and he offers a clear and powerful account of the way in which social institutions are constructed from these building blocks as established, interconnected sets of social practices. His book will be of interest to a wide range of readers in philosophy of mind, philosophy of social science, psychology and sociology.