Tacitus recognized the necessity for strong rulers but argued that more should be done to manage the succession of power and allow for the ascension of talent. He asserted that it was the dynastic ambitions of Rome's many emperors that caused the decline of moral and political life and precluded the possibility of recruiting leaders of real ability. Moreover, the dynastic temptation caused political instability because military force was now required for political change. His works point to the necessity of systematic institutional restraints on power for the preservation of liberty.