The paper deals with the argument against Dworkin’s interpretative turn put forward by Andrei Marmor. Mamor's claim is the following: a constructive theory of the interpretation and the identification of law is falsified by the conception of legitimate authority proposed by Joseph Raz. That argument consists in two passages. The first passage is concerned to show that Dworkin necessarily has to refute, out of a need for consistency within his theory of law, the communication-intention model of interpretation. The second passage affirms that Raz’s conception of legitimate authority makes the alternative model of interpretation and identification of law, the constructive model, not fitting in the legal sphere. The conclusion is that if Dworkin’s theory of law implies the constructive model and the latter does not adequately account for interpretative praxis in the legal sphere, then Dworkin’s conception of law cannot aspire to represent a way of going beyond legal positivism. The aim of this paper is to show some serious weaknesses of Marmor's argumentative strategy.