"Not only can you not step into the same river twice; it is not even the same you who can’t step into the same river twice. Everything modifies everything. There is no niche in the past waiting for him to come back and occupy it. Nature will tolerate a paradox, but she abhors a vacuum."

“I’ll follow the reedy tenor of his excuses and blast them with the bellowy bass of irrefutable logic!”

“It was one hell of an inspection when you went around finding how many sane men you had left.”

“Even rulers, notoriously the slowest of men to change, realized that something had to be done.”

“Blaine remembered how strange, dark, atavistic and noble Hull’s lordly selection of death has seemed. Pretentious, of course; but then, life itself was a pretension in the vast universe of unliving matter.”

“In a way it made no difference, since nothing is permanent except our illusions.”

“After many centuries we have rediscovered nature’s way of keeping populations in hand. Nature does it the old-fashioned way, by killing people.”