"A society that put more emphasis on birth than ability was likely to breed ability out of its ruling class."

“He was going to die. His mind flinched back in horror from that, but it was still there, grinning, implacable. His body would rot under the ground, while delicious things were still happening in the sunlight.”

“No progress, either moral or material, can be made in a world which is frozen, like ours, into a rigid mold of suppression of liberties.”

“Eagles had made a realist of him. He believed in facts, and in altering your viewpoint to fit them, no matter what they were. That was the way you survived and stayed sane; it was hard, it meant sacrifices—he had already lost many things that he valued deeply—but it was the only way.”

“Voluntary birth control methods only work on the people who choose to use ’em. A population check that doesn’t work on everybody doesn’t work at all, because it simply breeds out the ones who use it. The only population check that really works is one that affects everybody, like a limit of space or food.”

““Don’t lose your temper,” said Ruell evenly. “It’s your worst fault, except for ignorance.”

“Science fiction … means what we point to when we say it.”