When trying a case [the famous judge] L. Cassius never failed to inquire "Who gained by it?" Man's character is such that no one undertakes crimes without hope of gain.
To give and receive advice - the former with freedom, and yet without bitterness, the latter with patience and without irritation - is peculiarly appropriate to geniune friendship.
The mind becomes accustomed to things by the habitual sight of them, and neither wonders nor inquires about the reasons for things it sees all the time.
The evil implanted in man by nature spreads so imperceptibly, when the habit of wrong-doing is unchecked, that he himself can set no limit to his shamelessness.
They who say that we should love our fellow-citizens but not foreigners, destroy the universal brotherhood of mankind, with which benevolence and justice would perish forever.