“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.”

“Pyscho-history dealt not with man, but with man-masses. It was the science of mobs; mobs in their billions. It could forecast reactions to stimuli with something of the accuracy that a lesser science could bring to the forecast of a rebound of a billiard ball. The reaction of one man could be forecast by no known mathematics; the reaction of a billion is something else again.”

“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.”

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

“A "simple aspect of science" may be defined as one which, through good fortune, I happen to understand.”

“Give us but the chance and a new generation of Earthmen would grow to maturity, lacking insularity and believing wholeheartedly in the oneness of Man.”

“In all the known history of Mankind, advances have been made primarily in physical technology; in the capacity of handling the inanimate world about Man. Control of self and society has been left to to chance or to the vague gropings of intuitive ethical systems based on inspiration and emotion. As a result no culture of greater stability than about fifty-five percent has ever existed, and these only as the result of great human misery.”