"It takes a particular kind of a man to endure the shattering immensities of space and the paranoid-inducing stresses of threats from the unknown. It takes a man with a large and impervious ego and a consistently high degree of aggressive self-confidence. It takes a kind of a nut."

"Everything in space obeys the laws of physics. If you know these laws, and obey them, space will treat you kindly. And don't tell me that man doesn't belong out there. Man belongs wherever he wants to…"

"…People who know about these things say that the short story is the most challenging form, much more so than the novel, because of the precision required; sometimes you have to achieve as much as a no…"

"Power is so pleasant that men quickly learn to be greedy in the enjoyment of it, and to flatter themselves that patriotism requires them to be imperious."

"Our present knowledge of human perception leaves no doubt as to the general form of any theory which is to do justice to such knowledge: a theory of perception must be a field theory. By this we mean …"