Dworkin's theoretical disagreement argument, developed in Law's Empire, is presented in that work as the motivator for his interpretive account of law. Like Dworkin's earlier arguments critical of legal positivism, the argument from theoretical disagreement has generated a lively exchange with legal positivists. It has motivated three of them to develop innovative positivist positions. In its original guise, the argument from theoretical disagreement is presented as ‘the semantic sting argument’. However, the argument from theoretical disagreement has more than one version. (...) This article briefly discusses two versions and the leading replies to them, then focuses on the most influential version, directed at Hartian positivism. The article surveys the leading positivist rejoinders to the recast version, indicating key Dworkinian replies or assessing the strength of these rejoinders, and concludes with a rejoinder of its own, making a new case that the argument from theoretical disagreement isn't fatal for Hartian legal positivism. (shrink)