Kelsen s juridical system, through a heterodox perspective, could be seenas an efficient model for the emerging paradigm, based upon the belief that thecriticism of this author is due to misunderstanding of his proposals and/orhypothesis. The metatheoretical analysis is one of the methods that reconductKelsen s thoughts not as something antique, but as a breaktrough that could beused at the service of Post-Modernity. Still within the Modern paradigm, Kelsen´shypothesis are associated with a theoretical referential that is away of thelanguage`s conception as a representation of the real, highlighting, in Law´s PureTheory, a partial critique to Modernity. Kelsen, even not having the proposal ofasserting at some areas due to epistemic reasons, left blank spaces in his theorythat, using some new insights of areas such as psychoanalysis, could be used astools of a complete, not partial, critique to Modernity. Using a metapsychologicalanalysis of Kelsen s political theory concepts of liberty and equality and updatinghis concept of human nature, there is a new perspective through which is possibleto have a proper reading of Law´s Pure Theory, where sense s ethics is an explicitcondition to validation of juridical ordering and tool, non obsolete, to deal withthe problems of contemporaniety.