In the third book of the Annales Tacitus offers an extraordinary parenthesis of juridical history, explaining how the degradation of customs has made legislative provisions proliferate in a vicious and unstoppable circle, with the parallel increase of crimes and the consequent need for further coercive instruments. The lex, a necessary instrument for maintaining social order, in the hands of the rulers becomes an organ of oppression, a weapon used not so much to exercise justice, but to impose violence. If on a moral level the reasons of political expediency cannot overpower the sovereignty of the law, on the other hand the historian shows how Tiberius, autocratic and dissimulator, tries in every way to persuade the Roman people to reduce crucial events, such as the death of Germanicus, from the perspective that «princes are mortal, only the State is eternal» (III, 6, 3).
Keywords: Tacitus, Tiberius, Principate, Rome, Laws.
