AbstractThis paper makes a conceptual prescription: it argues that judges and lawyers should adopt a positivist concept of law, on normative grounds. The positivist view, I will argue, is more consistent with reasonable disagreement and majority rule than nonpositivist views, offers a better view of law’s moral standing, and is more consistent with what Dworkin called ‘integrity’ than non-positivism. As the paper explains, this is an argument about what I call the ‘operative’ concept of law. As such, the argument avoids potential problems for conceptual prescription, and shows why even those who adopt non-positivist views about the nature of law might accept it.