There are a dozen different ways of delivering destruction in impersonal wholesale, via ships or missiles of one sort or another, catastrophes so widespread, so unselective that the war is over because that nation or planet has ceased to exist. What we do is entirely different. We make war as personal as a punch in the nose. We can be selective, applying precisely the required amount of pressure at the specified point at a designated time. We've never been told to go down and kill or capture all left-handed redheads in a particular area, but if they tell us to, we can. We will.

Physicians had gone to their graves calling Pasteur a liar, a fool, or worse—without examining evidence which their “common sense” told them was impossible.

Geniuses and supergeniuses always make their own rules about sex as on everything else; they do not accept the monkey customs of their lessers.

Butterflies are self propelled flowers.

Nor would anybody suspect. If was one thing all people took for granted, was conviction that if you feed honest figures into a computer, honest figures come out. Never doubted it myself till I met a computer with a sense of humor.

Men rarely if ever dream up a god superior to themselves. Most gods have the manners and morals of a spoiled child.

He never gave up his search for the Door into Summer.