This dissertation examines the premise of methodological purity as a principle of Hans Kelsen´s Pure Theory of Law, in this perpetuation of the theoretical juristic common sense, revealing its mythic dimensions. A rereading of Kelsen is realized in the light of criticism of methodological purity developed by Luis Alberto Warat, principally in his work The Purity of Power. The study includes conceptual references of Roland Barthes, Gaston Bachelard and Antonio Negri, related to the proposals of creative illusory systems, such as immanent modernity and the transurrealism. That premise is contextualized in the modern paradigms as epistemological obstacles for the production of a critical wisdom which builds new objects of knowledge in the juridic field.