ABSTRACT When legal practice satisfies certain modest conditions of legitimacy, affirming the equal dignity of persons, the law is what it ought to be. It provides the morally appropriate basis for the resolution of disputes between people who may disagree about what justice, ideally conceived, requires. Specific rules or rulings are properly interpreted in accordance with legal and constitutional principle, which tracks the nature and boundaries of legitimate government. Procedural and substantive moral standards are encompassed within an appropriate conception of the rule of law. The law is thereby constituted the measure of justice for the political community: a public conception of justice is substituted for conflicting private ones. Our legal obligations are precisely the moral obligations we owe as citizens, faithful to that community. We honour the demands of justice by obedience to law – the law that obtains in virtue of adherence to the ideal of the rule of law.