"We convinced her of that. But forget it, chief. I'd rather not talk about it. Still, Allerton wasn't a born spaceman, and you know it. There's no such thing, except for extreme introverts, who aren't such good workers, anyway."
"We need spacemen. We need dedicated men who don't want to see their native planet. Either we control space or our enemy does."
"Then why don't you say it that way?"
"Well, because—"
"Because you're afraid to admit it even to yourself, that's why. Spacemen aren't born, chief. They are made. They are not particularly heroic or well-adjusted people. They are ordinary men with induced traumas and they don't want to go near Earth again, and we call them spacemen."
"It's for the security of the nation," said the government psychologist as he opened a new file....