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

“all the suffering that humanity ever knew can be traced to the one fact that no man in the history of the Galaxy, until Hari Seldon, and very few men thereafter, could really understand one another. Every human being lived behind an impenetrable wall of choking mist within which no other but he existed. Occasionally there were the dim signals from deep within the cavern in which another man was located - so that each might grope toward the other. Yet because they did not know one another, and could not understand one another, and dared not trust one another, and felt from infancy the terrors and insecurity of that ultimate isolation - there was the hunted fear of man for man, the savage rapacity of man toward man.”

“Every man's position on Earth is restricted to the distance he can walk.'-- "The Last Trump”

“I am trying now to re-create in my mind the picture of the man as I saw him in 1939- he, the revered author of Sinister Barriers, I the novice. I think I can rely on my near-photographic memory for the purpose. (I call it "near-photographic" because I can only remember things that happen to be lying around near photographs.)Let's see, as I recall, he is six-feet seven-inches tall (when he is sitting down, that is) with a long and majestic English face. Then, too, I distinctly remember, there was a small flashing golden aura about his head, the occasional play of hissing flashes when he moved it suddenly, and the distant rumble of thunder when he spoke.”

“The most hopelessly stupid man is he who is not aware he is wise.”

“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.”

“You are a military man and should know better. If there is one science into which man has probed continuously and successfully, it is that of military technology. No potential weapon would remain unrealized for ten thousand years.”