A nation can survive its fools, and even the ambitious. But it cannot survive treason from within. An enemy at the gates is less formidable, for he is known and carries his banner openly. But the traitor moves amongst those within the gate freely, his sly whispers rustling through all the alleys, heard in the very halls of government itself.
But if you should take the bond of goodwill out of the universe no house or city could stand, nor would even the tillage of the fields abide. If that statement is not clear, then you may understand how great is the power of friendship and of concord from a consideration of the results of enmity and disagreement. For what house is so strong, or what state so enduring that it cannot be utterly overthrown by animosities and division?
A careful physician . . . before he attempts to administer a remedy to his patient, must investigate not only the malady of the man he wishes to cure, but also his habits when in health, and his physical constitution.
When you wish to instruct, be brief; that men's [children's] minds take in quickly what you say, learn its lesson, and retain it faithfully. Every word that is unnecessary only pours over the side of a brimming mind.
Socrates, indeed, when he was asked of what country he called himself, said, "Of the world"; for he considered himself an inhabitant and a citizen of the whole world.