There can never be a man so lost as one who is lost in the vast and intricate corrdiors of his own lonely mind, where none may reach and none may save. There never was a man so helpless as one who cannot remember.

I accept nothing on authority. A hypothesis must be backed by reason, or else it is worthless.

Q. You do not consider your statement a disloyal one? A. No, sir. Scientific truth is beyond loyalty and disloyalty. Q. You are sure that your statement represents scientific truth? A. I am.

Victories over ingrained patterns of thought are not won in a day or a year.

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.

I don't say it was deliberate fraud. He was probably madly sincere, and sincerely mad.

An unpleasant nest of nasty, materialistic and aggressive people, careless of the rights of others, imperfectly democratic at home though quick to see the minor slaveries of others, and greedy without end.

It was the addition of status that brought the little things: a more comfortable seat here, a better cut of meat there, a shorter wait in line at the other place. To the philosophical mind, these items might seem scarcely worth any great trouble to acquire.Yet no one, however philosophical, could give up those privileges, once acquired, without a pang. That was the point.

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

There was no denying that he would always be conscious of the fact that an Earthman was an Earthman. He couldn't help that. That was the result of a childhood immersed in an atmosphere of bigotry so complete that it was almost invisible, so entire that you accepted its axioms as second nature. Then you left it and saw it for what it was when you looked back.

Just you think first, and don't bother to speak afterward, either.

The fall of Empire, gentlemen, is a massive thing, however, and not easily fought. It is dictated by a rising bureaucracy, a receding initiative, a freezing of caste, a damming of curiosity, a hundred other factors. It has been going on, as I have said, for centuries, and it is too majestic and massive a movement to stop.

Goodbye, friend Elijiah, and remember that, although people apply the phrase to Aurora, it is, from this point on, Earth itself that is the true World of the Dawn.

An atom blaster is a good weapon, but it can point both ways.

The newsmen were writing down sentences busily as Hoskins spoke to them. They did not understand and they were sure their readers would not, but it sounded scientific and that was what counted.

Trantor could win even such a war, but perhaps not without paying a price that would make victory only a pleasanter name for defeat.

There are degrees of justice, Elijah. When the lesser is incompatible with the greater, the lesser must give way.

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

Nonsense. You are a military man and should know better. If there is one science into which man has probed continuously and successfully, it is that of military technology. No potential weapon would remain unrealized for ten thousand years.

Milton Ashe is not the type to marry a head of hair and a pair of eyes.

Well, then, arrest him. You can accuse him of something or other afterward.

The work of each individual contributes to a totality and so becomes an undying part of the totality. That totality of human lives - past and present and to come - forms a tapestry that has been in existence now for many thousands of years and has been growing more elaborate and, on the whole, more beautiful in all that time. Even the Spacers are an offshoot of the tapestry and they, too, add to the elaborateness and beauty of the pattern. An individual life is one thread in the tapestry and what is one thread compared to the whole?

It is no one's privilege to despise another. It is only a hard-won right after long experience.

First, there must be an end to war and national rivalry and only then could one turn to the internal miseries that, after all, had external conflict as their chief cause.

A robot, the man had said, is logical but not reasonable.

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.

The Autarch maintained his indifferent calm, but a certain lack of certainty was gathering, and he did not like to experience a lack of certainty. He liked nothing which made him aware of limitations. An Autarch should have no limitations, and on Lingane he had none that natural law did not impose.

The machine is only a tool after all, which can help humanity progress faster by taking some of the burdens of calculations and interpretations off its back. The task of the human brain remains what it has always been; that of discovering new data to be analyzed, and of devising new concepts to be tested.

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

The same man who could not find it in his conscience to curb his curiosity into the nuclear studies that might someday kill half of Earth would risk his life to save that of an unimportant fellow man.

It's funny the respectable names you can give to superstition.

No one is so modest as not to believe himself a competent amateur sleuth.

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 happiness. As one climbs, one finds also fewer and fewer people to enjoy this more and more. Invariably, there is a preponderance of the dispossessed. And remember this, no matter how well off the bottom layers of the pyramid might be on an absolute scale, they are always dispossessed in comparison with the apex.So there is always social friction in ordinary human societies. The action of social revolution and the reaction of guarding against such revolution or combating it once it has begun are the causes of a great deal of the human misery with which history is permeated.

The whole business is the crudest sort of stratagem, since we have no way of foreseeing it to the end. It is a mere paying out of rope on the chance that somewhere along the length of it will be a noose.

I see your vile implication. My only explanation for it is that you are criminally insane.

There is nothing so eternally adhesive as the memory of power.

Courtiers don't take wagers against the king's skill.

To the rest of the Galaxy, if they are aware of us at all, Earth is but a pebble in the sky. To us it is home, and all the home we know.

It built itself up endlessly, like a chess game, and the telemetrists began to use a computer to program the computer that designed the program for the computer that programmed the robot-controlling computer.

Junz found revulsion growing strong within him. A planet full of people meant nothing against the dictates of economic necessity!

If one thing goes without saying, almost anything can.

I was once being interviewed by Barbara Walters [...] In between two of the segments she asked me [...] "But what would you do if the doctor gave you only six months to live?" I said, "Type faster." This was widely quoted, but the "six months" was changed to "six minutes," which bothered me. It's "six months."

There is more to a science fiction story than the science it contains.

The Dantean conceptions of Inferno were childish and unworthy of the Divine imagination: fire and torture. Boredom is much more subtle. The inner torture of a mind unable to escape itself in any way, condemned to fester in its own exuding mental pus for all time, is much more fitting. Oh, yes, my friend, we have been judged, and condemned, too, and this is not Heaven, but hell.

Of all the books I have ever worked on, I think Asimov's Guide to Shakespeare gave me the most pleasure, day in, day out. For months and months I lived and thought Shakespeare, and I don't see how there can be any greater pleasure in the world, any pleasure, that is, that one can indulge in for as much as ten hours without pause, day after day indefinitely.

Scientific theories can always be improved and are improved. That is one of the glories of science. It is the authoritarian view of the Universe that is frozen in stone and cannot be changed, so that once it is wrong, it is wrong forever.

Consider the most famous pure dystopian tale of modern times, 1984, by George Orwell (1903-1950), published in 1948 (the same year in which Walden Two was published). I consider it an abominably poor book. It made a big hit (in my opinion) only because it rode the tidal wave of cold war sentiment in the United States.

Earth governments in moments of stress are not famous for being reasonable.

All mankind, right down to those you most despise, are your neighbors.

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?