As in the "Histories", Tacitus maintains his thesis of the necessity of the principate. He says again that Augustus gave and warranted peace to the state after years of civil war, but on the other hand he shows us the dark side of life under the Caesars. He analyzes the characters of the Caesars as occasions arise, for example, when the narrative happened to be aiming at the undertakings of Tiberius. The history of the beginning of the principate is also the history of the end of the political freedom that the senatorial aristocracy, which Tacitus viewed as morally decadent, corrupt, and servile towards the emperor, had enjoyed during the republic. During Nero's reign there had been a widespread diffusion of literary works in favor of this suicidal "exitus illustrium virorum" ("end of the illustrious men"). Again, as in his "Agricola", Tacitus is opposed to those who chose useless martyrdom through vain suicides.