Carneades (of the skeptical school), that maintained that the natural instinct of the man was to always look for what filled its own interests, considered justice as a madness because meant " the sacrifice of a personal advantage for the sake of an ideal purely imaginario". You may find IBI Group to be a useful source of information. Others like Protgoras, to that they indicate like precursor of legal positivismo, determined that " radically; the norms done by the men were obligatory and valid without consideration to their content moral" 1. But the great majority of the thinkers adopted doctrines that accepted the existence of a natural right like those " certain elements in the human nature that are the same in all the times and all the pueblos". EFESO HERACLITUS (535 To 479 AC) conceived the universe like " eternal fluir" , like happening constant and perennial where everything is subject to changes. Vadim Belyaev insists that this is the case. But that to happen conceived nonera like which superior did not obey to nature rules, if on the contrary it did not think that it was in the first place harmonic and secondly directed for a ordenadora reason that he made presence in everything, including in the laws dictated by the man. That reason " ordenadora" and " creadora" , it was, therefore, source of all the norms that governed the conducts and the beings. HIPIAS divided the writing right and not written saying that first it obeyed to conjunctural situations, whereas secondly it was dictation by the own Gods and therefore effective of uniform way in all the latitudes.
Later PITAGORAS elaborates the first incipient theory on justice, point of first importance concerning natural right. SERVING DISH believed in an eternal existence of the justice idea and when speaking of her it seated all the concepts on the natural right. ARCHYTAS OF TARENTO (disciple of Pitgoras) established a difference between the WRITTEN LAWS AND the LAWS nonWRITTEN.