Clarke's Law of Evolution: It has yet to be proven that intelligence has any survival value.

Clarke's First Law: When a distinguished but elderly scientist states that something is possible, he is almost certainly right. When he states that something is impossible, he is very probably wrong.

Clarke's Second Law: The only way of discovering the limits of the possible is to venture a little way past them into the impossible.

Clarke's Third Law:. Any sufficiently advanced technology is indistinguishable from magic.

A hundred years ago, the electric telegraph made possible—indeed, inevitable—the United States of America. The communications satellite will make equally inevitable a United Nations of Earth; let us hope that the transition period will not be equally bloody.

Anything that is theoretically possible will be achieved in practice, no matter what the technical difficulties are, if it is desired greatly enough.

As three laws were good enough for Newton, I have modestly decided to stop there.
Commenting on Clarke's own three laws.

At the present rate of progress, it is almost impossible to imagine any technical feat that cannot be achieved, if it can be achieved at all, within the next five hundred years.

Human judges can show mercy. But against the laws of nature, there is no appeal.

I'm sure we would not have had men on the Moon if it had not been for Wells and Verne and the people who write about this and made people think about it. I'm rather proud of the fact that I know several astronauts who became astronauts through reading my books.

If we have learned one thing from the history of invention and discovery, it is that, in the long run—and often in the short one—the most daring prophecies seem laughably conservative.

In physics, mathematics, and astronautics [elderly] means over thirty; in the other disciplines, senile decay is sometimes postponed to the forties. There are, of course, glorious exceptions; but as every researcher just out of college knows, scientists of over fifty are good for nothing but board meetings, and should at all costs be kept out of the laboratory!
Defining 'elderly scientist' as in Clarke's First Law.

Information is not knowledge, knowledge is not wisdom, and wisdom is not foresight. Each grows out of the other, and we need them all.

It may be that the old astrologers had the truth exactly reversed, when they believed that the stars controlled the destinies of men. The time may come when men control the destinies of stars.

Politicians should read science fiction, not westerns and detective stories.

Science can destroy religion by ignoring it as well as by disproving its tenets. No one ever demonstrated, so far as I am aware, the nonexistence of Zeus or Thor—but they have few followers now.

The inspirational value of the space program is probably of far greater importance to education than any input of dollars... A whole generation is growing up which has been attracted to the hard disciplines of science and engineering by the romance of space.

There is hopeful symbolism in the fact that flags do not wave in a vacuum.

Clarke's First Law - Corollary: When, however, the lay public rallies round an idea that is denounced by distinguished but elderly scientists and supports that idea with great fervor and emotion—the distinguished but elderly scientists are then, after all, probably right.