Vagueness in law is typically extravagant, in the sense that it is possible for two competent users of the language, who understand the facts of each case, to take such different views as to the application of a vague law that there is not even any overlap between the cases that each disputant would identify as borderline. Extravagant vagueness is a necessary feature of legal systems. It is a reason to resist the urge to assert bivalence for propositions of law. The challenge – if bivalence is not asserted – is to articulate the principle of the rule of law in a way that is compatible with the possibility of indeterminacy in the application of vague laws.