Your assumptions are your windows on the world. Scrub them off every once in a while, or the light won’t come in.

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...

I tell you it’s deadly when you start thinking your wife might be right.

Violence is the last refuge of the incompetent.

Society is much more easily soothed than one’s own conscience.

I have never, in all my life, not for one moment, been tempted toward religion of any kind. The fact is that I feel no spiritual void. I have my philosophy of life, which does...

Civilizations have always been pyramidal in structure. As one climbs toward the apex of the social edifice, there is increased leisure and increasing opportunity to pursue hapiness. As one climbs, one finds also fewer and...

To [the government] it didn’t matter what happened to the American people as long as america in the abstract was kept strong.

A subtle thought that is in error may yet give rise to fruitful inquiry that can establish truths of great value.

It was obvious that bigotry was never a one-way operation, that hatred bred hatred!

Jokes of the proper kind, properly told, can do more to enlighten questions of politics, philosophy, and literature than any number of dull arguments.

The Imperial forces must keep their hands off, but they find that they can do much even so. Each sector is encouraged to be suspicious of its neighbors. Within each sector, economic and social classes...

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 — has become crucial to our salvation, if...

These are facts which, with the self-evident proposition that no being can create another being superior to itself, smashes your silly hypothesis to nothing.

For a wise man, I have been told, once said, ‘Gratitude is best and most effective when it does not evaporate in empty phrases.’ But alas, my lady, I am but a mass of empty...

…We now know the basic rules governing the universe, together with the gravitational interrelationships of its gross components, as shown in the theory of relativity worked out between 1905 and 1916. We also know the...

Human beings sometimes find a kind of pleasure in nursing painful emotions, in blaming themselves without reason or even against reason.

All roads lead to Trantor, and that is where all stars end.

There is a single light of science, and to brighten it anywhere is to brighten it everywhere.

The laws of history are as absolute as the laws of physics, and if the probabilities of error are greater, it is only because history does not deal with as many humans as physics does...

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

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...

It seems to me, Golan, that the advance of civilization is nothing but an exercise in the limiting of privacy.

Bible: Various portions of it, when properly interpreted, contain a code of behaviour which many men consider best suited to the ultimate happiness of mankind.

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.

All right, Schwartz, tackle my mind now. Go as deep as you want. I was born on Baronn in the Sirius Sector. I lived my life in an atmosphere of anti-Terrestrialism in the formative years,...

Suppose that we are wise enough to learn and know—and yet not wise enough to control our learning and knowledge, so that we use it to destroy ourselves? Even if that is so, knowledge remains...

There is nothing your knife handlers can do in the way of rioting and demonstrating that will have any permanent effect as long as, in the extremity, there is an army equipped with kinetic, chemical,...

And [Asimov]’ll sign anything, hardbacks, softbacks, other people’s books, scraps of paper. Inevitably someone handed him a blank check on the occasion when I was there, and he signed that without as much as a...

I grow grandiose, which is a good sign I should become prosaic.

Any technological advance can be dangerous. Fire was dangerous from the start, and so (even more so) was speech – and both are still dangerous to this day – but human beings would not be...

What would you consider a good job?” Answered as follows:”A good job is one in which I don’t have to work, and get paid a lot of money.”When I heard that I cheered and yelled...

How to enforce peace? Not by reason, certainly, nor by education.If a man could not look at the fact of peace and the fact of war and choose the former in preference to the latter,...

Well, sir to say that when the impossible has been eliminated, whatever remains, however improbable, is the truth, is to make the assumption, usually justified, that everything that is to be considered has indeed been...

Never let your sense of morals get in the way of doing what’s right.

To test a perfect theory with imperfect instruments did not impress the Greek philosophers as a valid way to gain knowledge.

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

Above all, never think you’re not good enough. Never think that. In life people will take you at your own reckoning.

In all the known history of Mankind, advances have been made primarily in physical technology; in the capacity of handling the inanimate world about Man. Control of self and society has been left to to...

It is not so much that I have confidence in scientists being right, but that I have so much in nonscientists being wrong.

It is not only the living who are killed in war.

I made up my mind long ago to follow one cardinal rule in all my writing—to be clear. I have given up all thought of writing poetically or symbolically or experimentally, or in any of...

Old men tend to forget what thought was like in their youth; they forget the quickness of the mental jump, the daring of the youthful intuition, the agility of the fresh insight. They become accustomed...

How often people speak of art and science as though they were two entirely different things, with no interconnection. An artist is emotional, they think, and uses only his intuition; he sees all at once...

Some readers may realize that this story, first published in 1956, has been overtaken by events. In 1965, astronomers discovered that Mercury does not keep one side always to the Sun, but has a period...

It is the obvious which is so difficult to see most of the time. People say ‘It’s as plain as the nose on your face.’ But how much of the nose on your face can...

One might accept death reasoningly, with every aspect of the conscious mind, but the body was a brute beast that knew nothing of reason.

One might suppose that reality must be held to at all costs. However, though that may be the moral thing to do, it is not necessarily the most useful thing to do. The Greeks themselves...

It has been my philosophy of life that difficulties vanish when faced boldly.

It was a long time since he’d done any actual clinical work, and obviously his sojourn among the academics at Saro University had attenuated the professional detachment that allows members of the healing arts to...