I joke sometimes to the effect that when I approach a part of a book where I must explain something I don't understand, I just type faster and faster and faster. Then, when I get to the part I don't understand, sheer inertia pushes me through. That's not literally true, of course, but there's something to it psychologically.

The fact is that I've never called myself a genius, and I think the term has been cheapened by overuse into meaninglessness. If other people want to call me that, that's their problem.

Writing is hard work. The fact that I love doing it doesn't make it less hard work. People who love tennis will sweat themselves to exhaustion playing it, and the love of the game doesn't stop the sweating. The casual assumption that writers are unemployed bums because they don't go to the office and don't have a boss is something every writer has to live with. I have never known a writer who hasn't suffered as a result of this, hasn't resented it, and hasn't dreamed of murdering the next person who says "Boy, you've sure got it made. You just sit there and toss off a story or something whenever you feel like it."

I am not a visual person. I have spent so many bounded years in my childhood that I have grown used to having books as my window on reality.

Scientists have pushed back the horizon of time from the biblical 6,000 years to 4,600,000,000 years for the age of Earth a 760,000-fold increase.

People don't stop things they enjoy doing just because they reach a certain age. They don't stop playing tennis just because they turn 40, they don't stop with sex just because they turn 40; they keep it up as long as they can if they enjoy it, and learning will be the same thing.

There are many aspects of the universe that still cannot be explained satisfactorily by science; but ignorance only implies ignorance that may someday be conquered. To surrender to ignorance and call it God has always been premature, and it remains premature today.

An optimistic view of the future would indicate that before long, the clear necessity of expanding humanity's horizons would cause ... space settlements to be built. The construction would also serve as a great project that not only would be clearly of great benefit, but might induce human cooperation in something large enough to fire the heart and mind, and make people forget the petty quarrels that have engaged them for thousands of years in wars over insignificant scraps of earthly territory.

Earth is a ball that is over 12,000 kilometres in diameter, and if it were modelled into an object the size of a billiard ball, with all its surface unevenness reproduced exactly to scale, the model would be smoother than an ordinary billiard ball and the ocean would be an all but unnoticeable mist of dampness over 70 percent of its surface.

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.

But suppose we were to teach creationism. What would be the content of the teaching? Merely that a creator formed the universe and all species of life ready-made? Nothing more? No details?

If one thing goes without saying, almost anything can.

The Bible and science agree in being unable to say anything certainly about what happened before the beginning. There is this difference. The Bible will never be able to tell us. It has reached its final form, and it simply doesn't say. Science, on the other hand, is still developing, and the time may come when it can answer questions that, at present, it cannot.

There is no version of primeval history, preceding the discoveries of modern science, that is as rational and as inspiring as that of the first eleven chapters of the Book of Genesis.

Religion is more conservative than any other aspect of human life.

No matter how outrageous a lie may be, it will be accepted if stated loudly enough and often enough.

It is by the Imperial Capital that contemporaries (and posterity, too) judge an Empire, and its magnificence impresses them mightily and leads them to judge the Emperor a great man and hero, even though it may all be based on robbery, and though the provinces of the Empire may be sunk in misery.

We can hope that the ways of peace will attract the Arabic nations, for their territory and opportunities are broad enough for immeasurable advance, if the energies vented in spleen, are turned instead to a modernisation of the technology, a restoration of the soil, and a renovation of the economic, social, and political structure of those great and venerable lands.

It is an odd fact that anyone who wishes to start a war must always make it appear that he is fighting in a just cause even if the real motive is naked aggression. Fortunately for the would-be aggressor, a "just cause" is very easy to find.

Probably, the most-often-repeated lesson in history is that foreigners who are called in to help one side in a civil war take over for themselves. It is a lesson that seems never to be learned despite endless repetition.

There has never been any custom, however useless it may become with changing conditions, that isn't clung to desperately simply because it is something old and familiar.

In the world of today can there be peace anywhere until there is peace everywhere?

Generals are usually a conservative force who can be relied on to oppose social change.

Often, writers on historical events tend to consider ... a loss of willingness to fight as a sign of "decadence," as though there were something despicable about not being a bully and not being willing to engage in mass murder. Perhaps we ought to feel instead that to cease to be warlike means to begin to be civilized and decent.

Start with a planet like the earth, with a complement of simple compounds bound to exist upon it, add the energy of a nearby sun, and you are bound to end with nucleic acids. You can't avoid it.

I don't believe in flying saucers... The energy requirements of interstellar travel are so great that it is inconceivable to me that any creatures piloting their ships across the vast depths of space would do so only in order to play games with us over a period of decades.

Private profit is often hidden under a careful coating of great patriotism.

History is a story without an end.

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.

An observer studying the Solar system dispassionately, and finding himself capable of bringing the four giant planets to his notice, could reasonably say that the Solar system consisted of one star, four planets, and some traces of debris.

It is the nature of science that answers automatically pose new and more subtle questions.

If, as I maintain and firmly believe, there is no objective definition of intelligence, and what we call intelligence is only a creation of cultural fashion and subjective prejudice, what the devil is it we test when we make use of an intelligence test?

My parents, both of whom spoke Russian fluently, made no effort to teach me Russian, but insisted on my learning English as rapidly and as well as possible. They even set about learning English themselves, with reasonable, but limited, success.In a way, I am sorry. It would have been good to know the language of Pushkin, Tolstoy, and Dostoevski. On the other hand, I would not have been willing to let anything get in the way of the complete mastery of English. Allow me my prejudice: surely there is no language more majestic than that of Shakespeare, Milton, and the King James Bible, and if I am to have one language that I know as only a native can know it, I consider myself unbelievably fortunate that it is English.

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

It is surely better to be wronged than to do wrong.

I wouldn't give an astrologer the time of day.

In memory yet green, in joy still felt, The scenes of life rise sharply into view. We triumph; Life's disasters are undealt, And while all else is old, the world is new.

I simply don't think it is reasonable to use IQ tests to produce results of questionable value, which may then serve to justify racists in their own minds and to help bring about the kinds of tragedies we have already witnessed earlier in this century.

Where any answer is possible, all answers are meaningless.

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.

Generals are, as a matter of course, allowed to be far more idiotic than ordinary human beings are permitted to be.

If you're going to write a story, avoid contemporary references. They date a story and they have no staying power.

Scientific writing is abhorrently stylized and places a premium on poor quality.

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.

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

Self-education is, I firmly believe, the only kind of education there is.