José Renato Gaziero Cella, Marlus Heriberto Arns de Oliveira

Eugenio Bulygin, in one of  his first published work, dated 1965 (Der Begriff der Wirkamkeit), considers the concept of effectiveness, in which it develops a critique of the theory of Alf Ross and, in order to clarify this criticism, reflects on the design of Hans Kelsen on the effectiveness of Law. From that moment it gave a true debate between Bulygin and Ross, but it was not news, by the year 2002, nearly 20 years after the death of Kelsen (1881-1973), any response to this Bulygin respect of that article 1965 until the Hans Kelsen Institute of Vienna located a manuscript, probably written between 1967 and 1970, in which Kelsen polemic with Bulygin on the subject of the validity and effectiveness of the Law, so that only recently Bulygin could present its rejoinder the debate in question. The article addresses this debate between Bulygin and Kelsen, where it comes to issues such as the justification of the judgment and logic deductibility of legal rules; the idea of judicial competence; applicability; the distinction between legal system and order. Anyway, we have from this debate an important key to the refinement of the pure theory of Law, their logical relations, their intangible basic premises as legal positivism, ethical skepticism, the separation between “is” (Sein) and “ougth” (Sollen) and neutrality scientific.