“Do not forget that a traitor within our ranks, known to us, can do more harm to the enemy than a loyal man can do good to us.”

“Jokes of the proper kind, properly told, can do more to enlighten questions of politics, philosophy, and literature than any number of dull arguments.”

“People who think they know everything are a great annoyance to those of us who do.”

“Those people who think they know everything are a great annoyance to those of us who do.”

“The Imperial forces must keep their hands off, but they find that they can do much even so. Each sector is encouraged to be suspicious of its neighbors. Within each sector, economic and social classes are encouraged to wage a kind of war with each other. The result is that all over Trantor it is impossible for the people to take united action. Everywhere, the people would rather fight each other than make a common stand against the central tyranny and the Empire rules without having to exert force.”

“Old men tend to forget what thought was like in their youth; they forget the quickness of the mental jump, the daring of the youthful intuition, the agility of the fresh insight. They become accustomed to the more plodding varieties of reason, and because this is more than made up by the accumulation of experience, old men think themselves wiser than the young.”

“Galaxy! When can a man know he is not a puppet? How can a man know he is not a puppet?”