Kelsen´s juridical system, through a heterodox perspective, could be seen as an efficient model for the emerging paradigm, based upon the belief that the criticism of this author is due to misunderstanding of his proposals and/or hypothesis. The metatheoretical analysis is one of the methods that reconduct Kelsen`s thoughts not as something antique, but as a breaktrough that could be used at the service of Post-Modernity. Still within the Modern paradigm, Kelsen´s hypothesis are associated with a theoretical referential that is away of the language`s conception as a representation of the real, highlighting, in Law´s Pure Theory, a partial critique to Modernity. Kelsen, even not having the proposal of asserting at some areas due to epistemic reasons, left blank spaces in his theory that, using some new insights of areas such as psychoanalysis, could be used as tools of a complete, not partial, critique to Modernity. Using a metapsychological analysis of Kelsen`s political theory concepts of liberty and equality and updating his concept of human nature, there is a new perspective through which is possible to have a proper reading of Law´s Pure Theory, where sense`s ethics is an explicit condition to validation of juridical ordering and tool, non obsolete, to deal with the problems of contemporaniety.