The correspondence between Pliny the Younger and Emperor Trajan provides a fascinating material for research into the genesis of the contemporary and modern legal norms. Interestingly, the scholars studying the roots of the principle of audiatur et altera pars have so far omitted that source, even though in one of the letters one can find quite a revealing imperial directive, that is audita utraque parte. The latter is even semantically close to the expressions of later origins, such as audi partem alteram and audiatur et altera pars. Nevertheless, taking into account the whole content of the correspondence, it is hard to accept the view that at the beginning of the 2nd century AD the Romans used the rules whose meaning would correspond to the contemporary legal reg- ulations. What stood in the way of such an advancement of Roman law was the political climate of the principate, together with the "constitutional" omnipotence of the emperor. Thus, in so far as the actions of the rulers and their representatives could be subject to ethical evaluation, on the other hand, they eluded any verification from the legal perspective.