The true discovery of America by mankind came when those first hunting bands crossed over from Siberia 25,000 years ago. This, however, never seems to count. When people speak of the "discovery of America" they invariably mean its discovery by Europeans.

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 is a systematic method for studying and working out those generalizations that seem to describe the behavior of the universe. It could exist as a purely intellectual game that would never affect the practical life of human beings either for good or evil, and that was very nearly the case in ancient Greece, for instance. Technology is the application of scientific findings to the tools of everyday life, and that application can be wise or unwise, useful or harmful. Very often, those who govern technological decisions are not scientists and know little about science.

Straightforward preaching spoils the effectiveness of a story. If you can't resist the impulse to improve your fellow human beings, do it subtly.

There is no way of being almost funny or mildly funny or fairly funny or tolerably funny. You are either funny or not funny and there is nothing in between. And usually it is the writer who thinks he is funny and the reader who thinks he isn't.

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.

I believe that only scientists can understand the universe. It is not so much that I have confidence in scientists being right, but that I have so much in nonscientists being wrong.

What, then, of human activities? Is humankind itself hastening its own end? Man has, for instance, been burning carbon-containing fuel — wood, coal, oil, gas — at a steadily accelerating rate. All these fuels form carbon dioxide. Some is absorbed by plants and the oceans but not as fast as it is produced. This means the carbon dioxide content of the air is going up — slightly but nevertheless up. Carbon dioxide retains heat, and even a small rise means a warming of the Earth's atmosphere. This may result in the melting of the polar ice caps with unusual speed, flooding the world before we have learned climate control. In reverse, our industrial civilization is making our atmosphere dustier so that it reflects more sunlight away and cools the Earth slightly — thus making possible a glacial advance in a few centuries, also before we have learned climate control.

The history of science is full of revolutionary advances that required small insights that anyone might have had, but that, in fact, only one person did.

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.