Cicero, On the Laws
3.13.30 (tr. Niall Rudd):
For just as the whole state is apt to be
infected by the vicious desires of its leaders, so it is healed and
set right by their restraint.
Ut enim cupiditatibus
principum et vitiis infici solet tota civitas, sic emendari et corrigi
If you're prepared to go back over
the records of history, it is plain that the state has taken its
character from that of its foremost men. Whatever changes have
taken place in the conduct of its leaders have been reproduced in
the lives of the people.
licet videre, si velis replicare memoriam temporum: qualescumque summi civitatis
viri fuerint, talem civitatem fuisse; quaecumque mutatio morum in principibus
exstiterit, eandem in populo secuturam.
secuturam APεL: securam B: secutam ς