“A faith that cannot survive collision with the truth is not worth many regrets.”

“The rash assertion that "God made man in His own image" is ticking like a time bomb at the foundation of many faiths.”

“It has yet to be proven that intelligence has any survival value.”

“Imagine that you're an intelligent extraterrestrial, concerned only with verifiable truths. You discover a species that has divided itself into thousands - no, by now millions - of tribal groups holding an incredible variety of beliefs about the origin of the universe and the way to behave in it. Although many of them have ideas in common, even when there's 99% overlap, the remaining one percent's enough to set them killing and torturing each other, over trivial points of doctrine, utterly meaningless to outsiders. "How to account for such irrational behavior? (...) religion was the by-product of fear - a reaction to a mysterious and often hostile universe. For much of human prehistory, it may have been a necessary evil - but why was it so much more evil than necessary - and why did it survive when it was no longer necessary?”

“It is not easy to see how the more extreme forms of nationalism can long survive when men have seen the Earth in its true perspective as a single small globe against the stars.”

“But please remember: this is only a work of fiction. The truth, as always, will be far stranger.”

“Every revolutionary idea seems to evoke three stages of reaction. They may be summed up by the phrases: (1) It's completely impossible. (2) It's possible, but it's not worth doing. (3) I said it was a good idea all along.”