“There had been a popular joke on Freedom, started by a man named Calder. Looking down from space, he had said, the dominant life forms on Earth were obviously the cereals and other grasses. They occupied all the most desirable and fertile land; and they had tamed insects and animals to care for them. In particular, they had domesticated the bipeds to nurture and cultivate them and to save and plant their seed. Now, watching the farmers, Alex could easily imagine that they were worshiping and genuflecting before their masters.”

“Long ago, Louis Wu had stood at the void edge of Mount Lookitthat. The Long Fall River, on that world, ends in the tallest waterfall in known space. Louis's eyes had followed it down as far as they could penetrate the void mist. The featureless white of the void itself had grasped at his mind, and Louis Wu, half hypnotized, had sworn to live forever. How else could he see all there was to see?Now he reaffirmed that decision.”

“For two hundred and fifty years the kzinti had not attacked human space. They had nothing to attack with. For two hundred and fifty years men had not attacked the kzinti worlds; and no kzin could understand it. Men confused them terribly.”

“The Product of Freedom and Security is a constant (F X S = k). Giving up freedom for security is beginning to look naive.”

“There were timelines branching and branching, a mega-universe of universes, millions more every minute. Billions? Trillions? The universe split every time someone made a decision. Split, so that every decision ever made could go both ways. Every choice made by every man, woman, and child was reversed in the universe next door.”

“Spray a book with insect spray, drop it in a bag, add some mothballs and seal it. Put it in another bag and seal it. Another. The packages piled up on the floor, each a book sealed in four plastic envelopes.”

“The dinosaurs became extinct because they didn't have a space program. And if we become extinct because we don't have a space program, it'll serve us right!”