In his rich discussion of the rule of law in Reciprocal Freedom, Ernest Weinrib observes that the prospectivity central to the rule of law seems incompatible with the apparent retroactivity of adjudication, for “parties to litigation are held to a norm of which they had no specific notice when the impugned conduct occurred.” Weinrib offers a deflationary response. Insofar as the legal materials from which any judicial opinion is crafted exist antecedently, parties are in fact on notice prior to the adjudication of their dispute. All a judicial decision does, on Weinrib’s view, is make “definitive what ought to and could have been done earlier on the basis of the law as it existed earlier.” This, I argue, does not take seriously the choices that judges face in resolving cases, for while they are constrained by existing legal materials, those materials seldom demand only one resolution, and so the problem of retroactivity remains.