The dissertation examines the theory Egológica Carlos Cossio, considering the developments proposed by the paradigm of complexity, in a proposal for transdisciplinarity to identify the legal phenomenon. The approach used employs the theme revealing method as a tool for interpreting the law. The work examines the
formation of the theory egológica, understood from the analysis of human behavior as the center of legal effectiveness. Demonstrating that were developed in the field of cognitive psychology to understanding the parameters of the decision process of individuals
