Scott Shapiro has recently argued that Ronald Dworkin posed a new objection to legal positivism in Law\u27s Empire, to which positivists, he says, have not adequately responded. Positivists, the objection goes, have no satisfactory account of what Dworkin calls theoretical disagreement about law, that is, disagreement about the grounds of law or what positivists would call the criteria of legal validity. I agree with Shapiro that the critique is new but disagree that it has not been met. Positivism cannot offer an explanation that preserves the Face Value of theoretical disagreements, because the only intelligible dispute about the criteria of legal validity is an empirical or head count dispute, that is, a dispute about what judges...