Thus, Plato created a system of low social mobility, but to allow the promotion and degradation of citizens in its merits. Portrait of a form of meritocracy, which can be understood as the first criterion for the Justice of the city-state Republican, also be used as a criterion to occupy the places mentioned in the society, the natural capabilities of each individual by measuring skills with the skills developed in each State or private. Therefore, according to this idea, platonic Justice proposes that the man is dedicated to his work, and the fundamental principles of the division of labour (social skills) were present since the formation of the City-State. He stressed the commitment to equality in Plato the intention, the main premise of his concept of justice. Maintain the stability of the State, through legal norms to ensure the effectiveness of the division of tasks which could be questioned by the principle of freedom, ends up being suffocated by law. Kelsen identifies an insurmountable problem in theory formulated by Plato, the absence of a material content of the law, i.e.

the notion of Justice is based on metaphysical criteria. Material of the law is absent in the thinking of the Greek philosopher and Kelsen aims not to justice, therefore, a simple rule of proof in the Constitution is not enough to achieve justice alone. Kelsen reveals that the Constitution, do not represent Plato law, but only the production method to govern on the basis of education. The Constitution has a platonic pedagogical content much more than legal or political. Afer also applies to double between good and bad for Plato is a tonic to define her idea of Justice, as well as noted Kelsen, Plato does not recognize through the perception of the senses. The object of knowledge is beyond the senses, or is outside the scope of the dialectic is experience.