question of whether the relevant moral principle was already part of the law before it was cited to justify a holding is an interesting one, but not much turns on it; in particular, answering that question will not tell us anything about the morality of the content of the law. In fact, I dont think positivism can tell us anything of interest about what judges or legislators should do. Those questions are left to theories of legitimacy to answer. Positivism is a theory of legality (i.e., what counts as law), and not a theory of legitimacy (i.e., what qualities law has to have to be legitimately enforced by coercive means). I take it, following Austin, that the question of what the content of the law is and the question of what the content of the law should be are two distinct questions that require different methodologies to answer.3 Many students and professors of legal philosophy in Brazil are not familiar with the exclusive/inclusive dispute in contemporary legal positivism. Can you give us a brief characterization of each position and your personal reasons to believe that inclusive legal positivism is a superior conception of law?The conceptual foundation of legal positivism consists in three commitments: the Social Fact Thesis, the Conventionality Thesis, and the Separability Thesis. The Social Fact Thesis asserts that the existence of law is made possible by certain kinds of social fact. The Conventionality Thesis claims that the criteria of validity are conventional in character. The Separability Thesis, at the most general level, denies that there is necessary overlap between law and morality.While the Separability Thesis thus implies that there are no necessary moral criteria of legal validity, it leaves open the question of whether there are possible moral criteria of validity. Inclusive legal positivists (also known as soft positivists and incorporationists) believe there can be such criteria; that is, they believe there are conceptually possible legal systems in which the criteria for legal validity include (or incorporate) moral principles. Prominent inclusive positivists include H.L.A. Hart, Jules Coleman, W.J. Waluchow, and Matthew Kramer. Exclusive legal positivists (also known as hard positivists) deny there can be moral criteria of validity. Exclusive positivists, like Joseph Raz, Scott Shapiro, and Andrei Marmor, claim the existence and content of law can always be determined by reference to social sources.The inclusive positivist position is a very weak one, and the exclusive positivist position is a very strong one. The inclusivist says no more than that it is possible for a legal system to have moral criteria of legality; in other words, the inclusivist claims that the idea of moral criteria of legality is not incoherent (in the sense that the idea of a married bachelor is incoherent). That is a very weak claim: out of the uncountably infinite number of possible worlds there are, at least one has moral criteria of legality. The exclusivist claim is much stronger: none of the uncountably large number of possible worlds in logical space has moral criteria of legality.I think that none of the exclusivist arguments against inclusive positivism works