Let there be but two occasions for speech - when the subject is one which you thoroughly know and when it is one on which you are compelled to speak. On these occasions alone is speech better than silence; on all others, it is better to be silent than to speak.

Conduct yourself towards your parents as you would have your children conduct themselves towards you.

It is not fitting that the evil produced by men should be imputed to things; let those bear the blame who make an ill use of things in themselves good.

Oratory is good only if it has the qualities of fitness for the occasion, propriety of style, and originality of treatment, while in the case of letters there is no such need whatsoever.

Regard as your most faithful friends, not those who praise everything you say or do, but those who criticize your mistakes.

Those who directed the state in the time of Solon and Cleisthenes did not establish a polity which ... trained the citizens in such fashion that they looked upon insolence as democracy, lawlessness as liberty, impudence of speech as equality, and licence to do what they pleased as happiness, but rather a polity which detested and punished such men and by so doing made all the citizens better and wiser.

Spend your leisure time in cultivating an ear attentive to discourse, for in this way you will find that you learn with ease what others have found out with difficulty.