But robots aside, why bother making a computer that compact? The units that make up a computer have been getting smaller and smaller, to be sure-from vacuum tubes to transistors to tiny integrated circuits and silicon chips. Suppose that, in addition to making the units smaller, we also make the whole structure bigger.

A brain that gets too large would eventually begin to lose efficiency because nerve impulses don't travel very quickly. Even the speediest nerve impulses travel at only about 3.75 miles a minute. A nerve impulse can flash from one end of the brain to the other in one four-hundred-fortieth of a second, but a brain 9 miles long, if we could imagine one, would require 2.4 minutes for a nerve impulse to travel its length. The added complexity made possible by the enormous size would fall apart simply because of the long wait for information to be moved and processed within it.

Computers, however, use electric impulses that travel at more than 11 million miles per minute. A computer 400 miles wide would still flash electric impulses from end to end in about one four-hundred-fortieth of a second. In that respect, at least, a computer of that asteroidal size could still process information as quickly as the human brain could.

If, therefore, we imagine computers being manufactured with finer and finer components, more and more intricately interrelated, and also imagine those same computers becoming larger and larger, might it not be that the computers would eventually become capable of doing all the things a human brain can do?

Is there a theoretical limit to how intelligent a computer can become?

I've never heard of any. It seems to me that each time we learn to pack more complexity into a given volume, the computer can do more. Each time we make a computer larger, while keeping each portion as densely complex as before, the computer can do more.

Eventually, if we learn how to make a computer sufficiently complex and sufficiently large, why should it not achieve a human intelligence?

Some people are sure to be disbelieving and say, "But how can a computer possibly produce a great symphony, a great work of art, a great new scientific theory?"

The retort I am usually tempted to make to this question is, "Can you?" But, of course, even if the questioner is ordinary, there are extraordinary people who are geniuses. They attain genius, however, only because atoms and molecules within their brains are arranged in some complex order. There's nothing in their brains but atoms and molecules. If we arrange atoms and molecules in some complex order in a computer, the products of genius should be possible to it; and if the individual parts are not as tiny and delicate as those of the brain, we compensate by making the computer larger.

Some people may say, "But computers can only do what they're programmed to do."

The answer to that is, "True. But brains can do only what they're programmed to do-by their genes. Part of the brain's programming is the ability to learn, and that will be part of a complex computer's programming."

In fact, if a computer can be built to be as intelligent as a human being, why can't it be made more intelligent as well?

Why not, indeed? Maybe that's what evolution is all about. Over the space of three billion years, hit-and-miss development of atoms and molecules has finally produced, through glacially slow improvement, a species intelligent enough to take the next step in a matter of centuries, or even decades. Then things will really move.

But if computers become more intelligent than human beings, might they not replace us? Well, shouldn't they? They may be as kind as they are intelligent and just let us dwindle by attrition. They might keep some of us as pets, or on reservations.

Then too, consider what we're doing to ourselves right now-to all living things and to the very planet we live on. Maybe it is time we were replaced. Maybe the real danger is that computers won't be developed to the point of replacing us fast enough.

Think about it!*

*I present this view only as something to think about. I consider a quite different view in "Intelligences Together" later in this collection.

The Laws Of Robotics It isn't easy to think about computers without wondering if they will ever "take over."

Will they replace us, make us obsolete, and get rid of us the way we got rid of spears and tinderboxes?

If we imagine computerlike brains inside the metal imitations of human beings that we call robots, the fear is even more direct. Robots look so much like human beings that their very appearance may give them rebellious ideas.

This problem faced the world of science fiction in the 19208 and 19308, and many were the cautionary tales written of robots that were built and then turned on their creators and destroyed them.

When I was a young man I grew tired of that caution, for it seemed to me that a robot was a machine and that human beings were constantly building machines. Since all machines are dangerous, one way or another, human beings built safeguards into them.

In 1939, therefore, I began to write a series of stories in which robots were presented sympathetically, as machines that were carefully designed to perform given tasks, with ample safeguards built into them to make them benign.

In a story I wrote in October 1941, I finally presented the safeguards in the specific form of "The Three Laws of Robotics. " (I invented the word robotics, which had never been used before.) Here they are: 1. A robot may not injure a human being or, through inaction, allow a human being to come to harm.

2. A robot must obey the orders given it by human beings except where those orders would conflict with the First Law.

3. A robot must protect its own existence except where such protection would conflict with the First and Second Law.

These laws were programmed into the computerized brain of the robot, and the numerous stories I wrote about robots took them into account. Indeed, these laws proved so popular with the readers and made so much sense that other science fiction writers began to use them (without ever quoting them directly-only I may do that), and all the old stories of robots destroying their creators died out.

Ah, but that's science fiction. What about the work really being done now on computers and on artificial intelligence? When machines are built that begin to have an intelligence of their own, will something like the Three Laws of Robotics be built into them?

Of course they will, assuming the computer designers have the least bit of intelligence. What's more, the safeguards will not merely be like the Three Laws of Robotics; they will be the Three Laws of Robotics.

I did not realize, at the time I constructed those laws, that humanity has been using them since the dawn of time. Just think of them as "The Three Laws of Tools," and this is the way they would read: 1. A tool must be safe to use.

(Obviously! Knives have handles and swords have hilts. Any tool that is sure to harm the user, provided the user is aware, will never be used routinely whatever its other qualifications.) 2. A tool must perform its function, provided it does so safely.

3. A tool must remain intact during use unless its destruction is required for safety or unless its destruction is part of its function.

No one ever cites these Three Laws of Tools because they are taken for granted by everyone. Each law, were it quoted, would be sure to be greeted by a chorus of "Well, of course!"

Compare the Three Laws of Tools, then, with the Three Laws of Robotics, law by law, and you will see that they correspond exactly. And why not, since the robot or, if you will, the computer, is a human tool?

But are safeguards sufficient? Consider the effort that is put into making the automobile safe-yet automobiles still kill 50,000 Americans a year. Consider the effort that is put into making banks secure-yet there are still bank robberies in a steady drumroll. Consider the effort that is put into making computer programs secure-yet there is the growing danger of computer fraud.

Computers, however, if they get intelligent enough to "take over," may also be intelligent enough no longer to require the Three Laws. They may, of their own benevolence, take care of us and guard us from harm.

Some of you may argue, though, that we're not children and that it would destroy the very essence of our humanity to be guarded.

Really? Look at the world today and the world in the past and ask yourself if we're not children-and destructive children at that-and if we don't need to be guarded in our own interest.

If we demand to be treated as adults, shouldn't we act like adults? And when do we intend to start?

Future Fantastic In the past, three fundamental advances in human communication evolved that altered every facet of our world enormously and permanently. The first advance was speech, the second writing, and the third printing.

Now we face a fourth advance in communication every bit as important as the first three-the computer. This fourth revolution will enable most human beings to be more creative than they've ever been before. And provided we do not destroy the world by nuclear warfare, overpopulation or pollution, we will have a world of the technochild-a world as different from our present one as today's is from the world of the caveman. How will the lives of the next generation be different from their parents and grandparents?

One immediate response is to view the computer merely as another form of amusement, rather like a super-TV. It can be used for complex games, for making contact with friends, or for various trivial pursuits. Still, such things can change the world. For one thing, communication by computer networks can wipe out the feeling of distance. It can make the globe seem like a neighborhood, and this can have important consequences-the development of the concept of humanity as a single society, not as a collection of endlessly and inevitably warring social segments. The world might develop a global lingua franca, a language (no doubt something quite close to today's English) that everyone can understand, even though people would retain their individual languages for local use.

Then, too, since communication will be so easy and since mechanical and electronic devices can be controlled remotely (telemetering, for example, makes it possible even now for engineers to send instructions to-and obtain obedience from-devices sailing past planets billions of miles away), computers will reduce the necessity of using physical transportation to gain or gather information.

There will, of course, be no bar to travel. You can still be a tourist or visit friends or family in person rather than by closed-circuit television. But you will not have to battle hordes of people merely to carry or receive information that can be transferred by computer.

This means that the technochildren of tomorrow will be accustomed to living in a decentralized world, to reaching out in a variety of ways from their homes-or wherever they are-to do what needs doing. At one and the same time, they will feel both entirely isolated and in total contact.

The children of the next generation-and the society they will create-will see the greatest impact from computers in the area of education. Currently our society is intent on educating as many children as possible. The limit in the number of teachers means that students learn in mass. Every student in a school district or state or nation is taught the same thing at the same time in more or less the same way. But because each child has individual interests and methods of learning, the experience of mass education turns out to be unpleasant. The result is that most adults resist the learning process in postschool life; they've had enough of it.

Learning could be pleasant, even all-absorbingly fascinating, if children studied something that specifically interested them individually, on their own time and in their own way. Such study is currently possible through public libraries. But the library is a clumsy tool. One must go there, borrowing is limited to a few volumes, and books must be returned after a short time.

Clearly the solution is to move libraries into the home. Just as record players brought home the concert hall and television brought home the movie theater, the computer can bring home the public library. Tomorrow's technochildren will have a ready means of sating their curiosity. They will know at an early age how to command their computers to give listings of materials. As their interests are aroused (and guided, it is to be hoped, by their teachers at school), they will learn more in less time and find new byways to follow.

Education will have a strong component of self-motivation added to it. The ability to follow a personal path will encourage the technochild to associate learning with pleasure and grow into a lively technoadult-eager, curious, and ready to expand the mental environment for as long as his or her brain remains physically undulled by the ravages of old age.

This new approach to education can also influence another area of life: work. Until now, most human beings have worked at jobs that seriously underutilized the brain. In the ages when work consisted largely of brutish physical labor, few ever had the chance to lift their eyes to the stars or ponder abstractions. Even when the Industrial Revolution brought machinery that could lift the load of physical labor from the backs of humanity, meaningless "skilled" work took its place. Today employees on the assembly line and in offices still perform jobs that require little thought.

For the first time in history, skilled machines, or robots, will be able to do those mindless jobs. Any job that is so simple and repetitive that a robot can do it as well as, if not better than, a person is beneath the dignity of the human brain. As technochildren turn into adults and move into the work world, they will have time to exercise more creativity, to work in the fields of drama, science, literature, government, and entertainment. And they will be ready for this kind of work as a result of the computerized revolution in education.

Some might believe that it's simply impossible to expect people to be creative in large numbers. But that thinking comes from a world in which only a few escape the mental destruction of jobs that don't use the brain. We've been through this before: It was always assumed that literacy, for example, was the province of the few who had minds peculiarly adapted to the complicated task of reading and writing. Of course, with the advent of printing and mass education, it turned out that most human beings could be literate.

What does all this mean? That we will be dealing with a world of leisure. Once computers and robots are doing the dull, mechanical work, the world will start running itself to a far greater extent than ever before. Will there be more "Renaissance people" as a result? Yes. Currently leisure is a small segment of life that is used narrowly because of lack of time, or is wasted on doing nothing in a desperate attempt to get far away from the hated workaday world. With leisure filling most of one's time, there will be no sensation of racing the clock, no compulsion to enter into a wild spree against the slavery of hateful work. People will sample a variety of interests without haste, become skillful or knowledgeable in a number of areas, and cultivate different talents at various times.

This is not just guesswork. There have been eras in history when people had slaves-the brutalized, human version of the computer-to do the work for them. Others have had patrons to support them. When even a few people have had ample leisure time to pursue their interests, the result has been an explosion of variegated culture. The Golden Age of Athens in the late fifth century B.C. and the Italian Renaissance in the 14th to 16th centuries are the most famous examples.

Not only will people have the freedom to pursue hobbies and interests and dreams, but a great number of them will also want to share their talents. So many of us have a bit of the ham in us. We sing in the shower, take part in amateur theatrical productions, or love to swing along in parades. It is my guess that the 21st century may see a society in which one-third of the population will be engaged in entertaining the other two-thirds.

And there are bound to be new forms of entertainment that one can now foresee only dimly. Three-dimensional TV is easy to forecast. And space may become a new arena for activity. In near-zero gravity, for example, the manipulation of balls may produce far more complicated forms of tennis or soccer. Ballet and even social dancing may become incredibly startling and require a new kind of coordination that's delightful to watch, as it will be as easy to move up and down as it is to move forward and backward or left and right.

What about those people who choose not to share their bents and interests and instead retire into worlds of their own? Someone who is interested, for example, in learning about the history of costumes and who is capable of exploring the libraries of the world from an isolated comer might simply stay there. Might we, then, find ourselves in a society in which an unprecedented number of people are intellectual hermits? Might we breed a race of introverts?

I think the chances are slim. People who grow ferociously interested in one aspect of knowledge or expertise are quite likely to be filled with missionary zeal. They will want to share their knowledge with others. Even today, someone who has an obscure field of interest is far more likely to want to explain it to everyone he or she meets than to sit silently in a comer. If there's any danger, it's that an arcane interest will nurture a loquacious bore rather than a hermit.

We must not forget the tendency of those who share interests to wish to get together, to form a temporary subuniverse that is a haven of concentrated special fascination. In the 19708, for example, someone had the idea of organizing a convention for Star Trek fans, expecting a few hundred at most to attend. Instead, fans poured in by the thousands (and television was supposed to be an isolating medium!). On-line gatherings, in which the computer is the medium and people are actively involved, will experience similarly high levels of participation.

And in between the formal get-togethers, there will be a kaleidoscope of people linked into global communities by computerized communication. Perpetual conventions will take place, in which individuals continually drop in and out, bringing in findings or ideas and leaving stimulated. There will be a constant melange of teaching and learning.

What I foresee is a society in intense creative ferment, people reaching out to others, new thoughts arising and spreading at a speed never before imagined, change and variety filling the planet (to say nothing of the smaller, artificial worlds that will be constructed in space). It will be a new world that will look back at earlier centuries as having been only half alive.

The Machine And The Robot To a physicist, a machine is any device that transfers a force from the point where it is applied to another point where it is used and, in the process, changes its intensity or direction.

In this sense it is difficult for a human being to make use of anything that is not part of his body without, in the process, using a machine. A couple of million years ago, when one could scarcely decide whether the most advanced hominids were more humanlike than apelike, pebbles were already being chipped and their sharp edges used to cut or scrape.

And even a chipped pebble is a machine, for the force applied to the blunt edge by the hand is transmitted to the sharp end and, in the process, intensified. The force spread over the large area of the blunt end is equal to the force spread over the small area of the sharp end. The pressure (force per area) is therefore increased, and without ever increasing the total force, that force is intensified in action. The sharp-edge pebble could, by the greater pressure it exerts, force its way through an object, as a rounded pebble (or a man's hand) could not.

In actual practice, however, few people, other than physicists at their most rigid, would call a chipped pebble a machine. In actual practice, we think of machines as relatively complicated devices, and are more likely to use the name if the device is somewhat removed from direct human guidance and manipulation.

The further a device is removed from human control, the more authentically mechanical it seems, and the whole trend in technology has been to devise machines that are less and less under direct human control and more and more seem to have the beginning of a will of their own. A chipped pebble is almost part of the hand it never leaves. A thrown spear declares a sort of independence the moment is its released.

The clear progression away from direct and immediate control made it possible for human beings, even in primitive times, to slide forward into extrapolation, and to picture devices still less controllable, still more independent than anything of which they had direct experience. Immediately we have a form of fantasy-which some, defining the term more broadly than I would, might even call science fiction.

Man can move on his feet by direct and intimate control; or on horseback, controlling the more powerful animal muscles by rein and heel; or on ship, making use of the invisible power of the wind. Why not progress into further etherealization by way of seven-league boots, flying carpets, self-propelled boats. The power used in these cases was "magic," the tapping of the superhuman and transcendental energies of gods or demons.

Nor did these imaginings concern only the increased physical power of inanimate objects, but even increased mental power of objects which were still viewed as essentially inanimate. Artificial intelligence is not really a modern concept.

Hephaistos, the Greek god of the forge, is pictured in the Iliad as having golden mechanical women, which were as mobile and as intelligent as flesh-and-blood women, and which helped him in his palace.

Why not? After all, if a human smith makes inanimate metal objects of the base metal iron, why should not a god-smith make far more clever inanimate metal objects of the noble metal gold? It is an easy extrapolation, of the sort that comes as second nature to science fiction writers (who, in primitive times, had to be myth-makers, in default of science).

But human artisans, if clever enough, could also make mechanical human beings. Consider Talos, a bronze warrior made by that Thomas Edison of the Greek myths, Oaedalus. Talos guarded the shores of Crete, circling the island once each day and keeping off all intruders. The fluid that kept him alive was kept within his body by a plug at his heel. When the Argonauts landed on Crete, Medea used her magic to pull out the plug and Talos lost all his pseudoanimation.

(It is easy to ascribe a symbolic meaning to this myth. Crete, starting in the fourth millennium B.C., before the Greeks had yet entered Greece, had a navy, the first working navy in human history. The Cretan navy made it possible for the islanders to establish an empire over what became the nearby islands and mainland. The Greek barbarians, invading the land, were more or less under Cretan dominion to begin with. The bronze-armored warriors carried by the ships guarded the Cretan mainland for two thousand years-and then failed. The plug was pulled, so to speak, when the island of Thera exploded in a vast volcanic eruption in 1500 B.C. and a tsunami greatly weakened the Cretan civilization-and the Greeks took over. Still, the fact that a myth is a sort of vague and distorted recall of something actual does not alter its function of indicating a way of human thinking.) From the start, then, the machine has faced mankind with a double aspect. As long as it is completely under human control, it is useful and good and makes a better life for people. However, it is the experience of mankind (and was already his experience in quite early times) that technology is a cumulative thing, that machines are invariably improved, and that the improvement is always in the direction of etherealization, always in the direction of less human control and more auto-control-and at an accelerating rate.

As the human control decreases, the machine becomes frightening in exact proportion. Even when the human control is not visibly decreasing, or is doing so at an excessively low rate, it is a simple task for human ingenuity to look forward to a time when the machine may go out of control altogether, and the fear of that can be felt in advance.

What is the fear?

The simplest and most obvious fear is that of the possible harm that comes from machinery out of control. In fact, any technological advance, however fundamental, has the double aspect of good/harm and, in response, is viewed with a double aspect of love/fear.

Fire warms you, gives you light, cooks your food, smelts your ore-and, out of control, burns and kills. Your knives and spears kill your animal enemies and your human foes and, out of your control, are used by your foes to kill you. You can run down the list and build examples indefinitely and there has never been any human activity which, on getting out of control and doing harm, has raised the sigh among many of, "Oh, if we had only stuck to the simple and virtuous lives of our ancestors who were not cursed with this new-fangled misery."

Yet is this fear of piecemeal harm from this advance or that the kind of deep-seated terror so difficult to express that it finds its way into the myths?

I think not. Fear of machinery for the discomfort and occasional harm it brings has (at least until very recently) not moved humanity to more than that occasional sigh. The love of the uses of machinery has always far overbalanced such fears, as we might judge if we consider that very rarely in the history of mankind has any culture voluntarily given up significant technological advance because of the inconvenience or harm of its side effects. There have been involuntary retreats from technology as a result of warfare, civil strife, epidemics, or natural disasters, but the results of that are precisely what we call a "dark age" and the population suffering from one does its best over the generations to get back on the track and restore the technology.

Mankind has always chosen to counter the evils of technology, not by abandonment of technology, but by additional technology. The smoke of an indoor fire was countered by the chimney. The danger of the spear was countered by the shield. The danger of the mass army was countered by the city wall.

This attitude, despite the steady drizzle of backwardist outcries, has continued to the present. Thus the characteristic technological product of our present life is the automobile. It pollutes the air, assaults our eardrums, kills fifty thousand Americans a year and inflicts survivable injuries on hundreds of thousands.

Does anyone seriously expect Americans to give up their murderous little pets voluntarily? Even those who attend rallies to denounce the mechanization of modern life are quite likely to reach those rallies by automobile.

The first moment when the magnitude of possible evil was seen by many people as uncounterable by any conceivable good came with the fission bomb in 1945. Never before had any technological advance set off demands for abandonment by so large a percentage of the population.

In fact, the reaction to the fission bomb set a new fashion. People were readier to oppose other advances they saw as unacceptably harmful in their side effects-biological warfare, the SST, certain genetic experiments on micro-organisms, breeder reactors, spray cans.

And even so, not one of these items has yet been given up.

But we're on the right track. The fear of the machine is not at the deepest level of the soul if the harm it does is accompanied by good, too; or if the harm is merely to some people-the few who happen to be on the spot in a vehicular collision, for instance.

The majority, after all, escape, and reap the good of the machine.

No, it is when the machine threatens all mankind in any way so that each individual human being begins to feel that he, himself, will not escape, that fear overwhelms love.

But since technology has begun to threaten the human race as a whole only in the last thirty years, were we immune to fear before that-or has the human race always been threatened?

After all, is physical destruction by brute energy of a type only now in our fist, the only way in which human beings can be destroyed? Might not the machine destroy the essence of humanity, our minds and souls, even while leaving our bodies intact and secure and comfortable?

It is a common fear, for instance, that television makes people unable to read and pocket computers will make them unable to add. Or think of the Spartan king who, on observing a catapult in action, mourned that that would put an end to human valor.

Certainly such subtle threats to humanity have existed and been recognized through all the long ages when man's feeble control over nature made it impossible for him to do himself very much physical harm.

The fear that machinery might make men effete is not yet, in my opinion, the basic and greatest fear. The one (it seems to me) that hits closest to the core is the general fear of irreversible change. Consider: There are two kinds of change that we can gather from the universe about us. One is cyclic and benign.

Day both follows and is followed by night. Summer both follows and is followed by winter. Rain both follows and is followed by clear weather, and the net result is, therefore, no change. That may be boring, but it is comfortable and induces a feeling of security.

In fact, so comfortable is the notion of short-term cyclic change implying long-term changelessness, that human beings labor to find it everywhere. In human affairs, there is the notion that one generation both follows and is followed by another, that one dynasty both follows and is followed by another, that one empire both follows and is followed by another. It is not a good analogy to the cycles of nature since the repetitions are not exact, but it is good enough to be comforting.

So strongly do human beings want the comfort of cycles that they will seize upon one even when the evidence is insufficient-or even when it actually points the other way.

With respect to the universe, what evidence we have points to a hyperbolic evolution; a universe that expands forever out of the initial big bang and ends as formless gas and black holes. Yet our emotions drag us, against the evidence, to notions of oscillating, cyclic, repeating universes, in which even the black holes are merely gateways to new big bangs.

But then there is the other change, to be avoided at all costs-the irreversible, malignant change; the one-way change; the permanent change; the change-never-to-return.

What is so fearful about it? The fact is that there is one such change that lies so close to ourselves that it distorts the entire universe for us.

We are, after all, old, and though we were once young we shall never be young again. Irreversible! Our friends are dead, and though they were once alive, they shall never be alive again. Irreversible! The fact is that life ends in death and that is not a cyclic change and we fear that end and know it is useless to fight it.