Richard Posner discusses the structure and behaviour of the legal profession; constitutional theory; interdisciplinary approaches to law; the nature of legal reasoning; and legal pragmatism. Although written by a sitting judge, the book does not avoid controversy, and contains frank appraisals of feminist and critical race theories, the behaviour of the German and British judiciaries in wartime, and the excesses of social constructionist theories of sexual behaviour. Throughout, the book is unified by Posner's stance, which is pragmatic in philosophy, economic in methodology, and liberal (in the sense of John Stuart Mill's liberalism) in politics. Eschewing jargon and technicalities, it should make a contribution to the debate about the role of law in our society.