The most exciting phrase to hear in science, the one that heralds new discoveries, is not 'Eureka!', but 'That's funny ...'

The saddest aspect of life right now is that science gathers knowledge faster than society gathers wisdom.

Outside intelligences, exploring the Solar System with true impartiality, would be quite likely to enter the Sun in their records thus: Star X, spectral class G0, 4 planets plus debris. Often misquoted as "Jupiter plus debris"

What I will be remembered for are the Foundation Trilogy and the Three Laws of Robotics. What I want to be remembered for is no one book, or no dozen books. Any single thing I have written can be paralleled or even surpassed by something someone else has done. However, my total corpus for quantity, quality and variety can be duplicated by no one else. That is what I want to be remembered for.

Science fiction writers foresee the inevitable, and although problems and catastrophes may be inevitable, solutions are not.

People are entirely too disbelieving of coincidence. They are far too ready to dismiss it and to build arcane structures of extremely rickety substance in order to avoid it. I, on the other hand, see coincidence everywhere as an inevitable consequence of the laws of probability, according to which having no unusual coincidence is far more unusual than any coincidence could possibly be.

Individual science fiction stories may seem as trivial as ever to the blinder critics and philosophers of today — but the core of science fiction, its essence, the concept around which it revolves, has become crucial to our salvation if we are to be saved at all.

It is change, continuing change, inevitable change, that is the dominant factor in society today. No sensible decision can be made any longer without taking into account not only the world as it is, but the world as it will be

I am an atheist, out and out. It took me a long time to say it. I've been an atheist for years and years, but somehow I felt it was intellectually unrespectable to say one was an atheist, because it assumed knowledge that one didn't have. Somehow, it was better to say one was a humanist or an agnostic. I finally decided that I'm a creature of emotion as well as of reason. Emotionally, I am an atheist. I don't have the evidence to prove that God doesn't exist, but I so strongly suspect he doesn't that I don't want to waste my time. Free Inquiry (Spring 1982)

If my doctor told me I had only six minutes to live, I wouldn’t brood. I’d type a little faster.

Imagine the people who believe such things and who are not ashamed to ignore, totally, all the patient findings of thinking minds through all the centuries since the Bible was written. And it is these ignorant people, the most uneducated, the most unimaginative, the most unthinking among us, who would make themselves the guides and leaders of us all; who would force their feeble and childish beliefs on us; who would invade our schools and libraries and homes. I personally resent it bitterly. 1994

Creationists make it sound as though a "theory" is something you dreamt up after being drunk all night.

I don't believe in an afterlife, so I don't have to spend my whole life fearing hell, or fearing heaven even more. For whatever the tortures of hell, I think the boredom of heaven would be even worse.

Violence is the last refuge of the incompetent.

It pays to be obvious, especially if you have a reputation for subtlety.

A fire eater must eat fire even if he has to kindle it himself.

Never let your sense of morals prevent you from doing what is right.

There's something about a pious man such as he. He will cheerfully cut your throat if it suits him, but he will hesitate to endanger the welfare of your immaterial and problematical soul.

Now any dogma, based primarily on faith and emotionalism, is a dangerous weapon to use on others, since it is almost impossible to guarantee that the weapon will never be turned on the user.

A robot may not injure a human being, or, through inaction, allow a human being to come to harm. "The First Law of Robotics"