Robert A. Heinlein

"Aside from mathematics, just two things worth doing—kill a man and love a woman. He had done both; he was rich."

"What good is the race of man? Monkeys, he thought, monkeys with a spot of poetry in them, cluttering and wasting a second-string planet near a third-string star. But sometimes they finish in style."

"Earth, seen from space, looked as it had looked in color-stereo pictures, but he found that the real thing is as vastly more satisfying as a hamburger is better than a picture of one."

"“Funny sort of science! I guess they were pretty ignorant in those days.” “Don’t go running down our grandfathers. If it weren’t for them, you and I would be squatting in a cave, scratching fleas. No, Bub, they were pretty sharp; they just didn’t have all the facts. We’ve got more facts, but that doesn’t make us smarter.”"

"“I don’t like cats.” “Ever lived with a cat? No, I see you haven’t. How can you have the gall not to like something you don’t know anything about? Wait till you’ve lived with a cat, then tell me what you think. Until then...well, who told you you were entitled to an opinion?” “Huh? Why, everybody is entitled to his own opinion!” “Nonsense, Bub. Nobody is entitled to an opinion about something he is ignorant of. If the Captain told me how to bake a cake, I would politely suggest that he not stick his nose into my trade...contrariwise, I never tell him how to plan an orbit to Mars.”"

"Hundred dollar bills have a hypnotic effect on a person not used to them."

"Hans had courage to burn. If he had been willing to knuckle under to the Nazis he would have stayed at Kaiser Wilhelm Institute. But Hans was a scientist. He wouldn’t trim his notion of truth to fit political gangsters."

"“I was just trying to show you,” he went on, “just how insubstantial a ‘common sense’ idea can be when you pin it down. Neither ‘common sense’ nor ‘logic’ can prove anything. Proof comes from experiment, or to put it another way, from experience, and from nothing else.”"

"“You know the answers, but just between ourselves, that sketch smells a bit. It’s sloppy.” “I never did have any artistic talent,” Art said defensively. “I’d rather take a photograph any day.” “You’ve taken too many photographs, maybe. As for artistic talent, I haven’t any either, but I learned to sketch. Look, Art—the rest of you guys get this, too—if you can’t sketch, you can’t see. If you really see what you’re looking at, you can put it down on paper, accurately. If you really remember what you have looked at, you can sketch it accurately from memory.” “But the lines don’t go where I intend them to.” “A pencil will go where you push it. It hasn’t any life of its own. The answer is practice and more practice and thinking about what you are looking at. All of you lugs want to be scientists. Well, the ability to sketch accurately is as necessary to a scientist as his slipstick. More necessary, you can get along without a slide rule.”"

"The door dilated."

"I think that science fiction, even the corniest of it, even the most outlandish of it, no matter how badly it's written, has a distinct therapeutic value because all of it has as its primary postulate that the world does change. I cannot overemphasize the importance of that idea."