Izumi Aizu

"Who should make the truly global decisions, and how?"

As we all use the global medium, Internet, people who are running it behind is making the decisions on how to run this medium. So far so good. But not anymore.

With all the ICANN process, commercialization of Domain Name registration, expanding the new gTLDs, one can ask: who are entitled to make these decisions, and how come they can decide that way?

Despite the growing digital divide, the number of people who use the Net is still exploding, even in the developing side of the world. What is fair, what is democratic, what kind of principles can we all agree on this single global complex system, from all corners of the world is my question of the year to come.

IZUMI AIZU, a researcher and promoter of the Net in Asia since mid 80s, is principal, Asia Network Research and Senior Research Fellow at GLOCOM (Center for Global Communications), at the International University of Japan.

Alun Anderson

"Why are humans smarter than other animals?"

Such a simple question. Many of you might think "Has that question really disappeared?" Some questions disappear for ever because they have been answered. Some questions go extinct because they were bad questions to begin with. But there are others that appear to vanish but then we find that they are back with us again in a slightly different guise. They are questions that are just too close to our hearts for us to let them die completely.

For millennia, human superiority was taken for granted. From the lowest forms of life up to humans and then on to the angels and God, all living thing were seen as arranged in the Great Chain of Being. Ascend the chain and perfection grows. It is a hierarchical philosophy that conveniently allows for the exploitation of dumber beasts — of other species or races — as a right by their superiors. We dispose of them as God disposes of us.

The idea of human superiority should have died when Darwin came on the scene.

Unfortunately, the full implications of what he said have been difficult to take in: there is no Great Chain of Being, no higher and no lower. All creatures have adapted effectively to their own environments in their own way. Human "smartness" is just a particular survival strategy among many others, not the top of a long ladder.

It took a surprisingly long time for scientist to grasp this. For decades, comparative psychologists tried to work out the learning abilities of different species so that they could be arranged on a single scale. Animal equivalents of intelligence tests were used and people seriously asked whether fish were smarter than birds. It took the new science of ethology, created by Nobel-prize winners Konrad Lorenz, Niko Tinbergen and Karl von Frisch, to show that each species had the abilities it needed for its own lifestyle and they could not be not arranged on a universal scale. Human smartness is no smarter than anyone else's smartness. The question should have died for good.

Artificial intelligence researchers came along later but they too could not easily part from medieval thinking. The most important problems to tackle were agreed to be those that represented our "highest" abilities. Solve them and everything else would be easy. As a result, we have ended up with computer programs that can play chess as well as a grandmaster. But unfortunately we have none that can make a robot walk as well as a 2-year old, yet alone run like a cat. The really hard problems turn out to be those that we share with "lower" animals.
Strangley enough, even evolutionary biologists still get caught up with the notion that humans stand at the apex of existence. There are endless books from evolutionary biologists speculating on the reasons why humans evolved such wonderful big brains, but a complete absence of those which ask if a big brains is a really useful organ to have. The evidence is far from persuasive. If you look at a wide range of organisms, those with bigger brains are generally no more successful than those with smaller brains — hey go extinct just as fast.
Of course, it would be really nice to sample a large range of different planets where life is to be found and see if big-brained creatures do better over really long time scales (the Earth is quite a young place). Unfortunately, we cannot yet do that, although the fact that we have never been contacted by any intelligent life from older parts of the Universe suggests that it usually comes to a bad end.

Still, as we are humans it's just so hard not to be seduced by the question "What makes us so special" which is just the same as the question above but in a different form. When you switch on a kitchen light and see a cockroach scuttle for safety you can't help seeing it as a lower form of life. Unfortunately, there are a lot more of them than there are of us and they have been around far, far longer. Cockroach philosophers doubtless entertain their six-legged friends by asking "What makes us so special".

ALUN ANDERSON is Editor-in-Chief of New Scientist.

Philip W. Anderson

"A question no longer: what is the Theory of Every Thing?"

My colleagues in the fashionable fields of string theory and quantum gravity advertise themselves as searching desperately for the 'Theory of Everything", while their experimental colleagues are gravid with the "God Particle", the marvelous Higgson which is the somewhat misattributed source of all mass. (They are also after an understanding of the earliest few microseconds of the Big Bang.) As Bill Clinton might remark, it depends on what the meaning of "everything" is. To these savants, "everything" means a list of some two dozen numbers which are the parameters of the Standard Model. This is a set of equations which already exists and does describe very well what you and I would be willing to settle for as "everything". This is why, following Bob Laughlin, I make the distinction between "everything" and "every thing". Every thing that you and I have encountered in our real lives, or are likely to interact with in the future, is no longer outside of the realm of a physics which is transparent to us: relativity, special and general; electromagnetism; the quantum theory of ordinary, usually condensed, matter; and, for a few remote phenomena, hopefully rare here on earth, our almost equally cut-and-dried understanding of nuclear physics. [Two parenthetic remarks: 1) I don't mention statistical mechanics only because it is a powerful technique, not a body of facts; 2) our colleagues have done only a sloppy job so far of deriving nuclear physics from the Standard Model, but no one really doubts that they can.]

I am not arguing that the search for the meaning of those two dozen parameters isn't exciting, interesting, and worthwhile: yes, it's not boring to wonder why the electron is so much lighter than the proton, or why the proton is stable at least for another 35 powers of ten years, or whether quintessence exists. But learning why can have no real effect on our lives, spiritually inspiring as it would indeed be, even to a hardened old atheist like myself.

When I was learning physics, half a century ago, the motivation for much of what was being done was still "is quantum theory really right?" Not just QED, though the solution of that was important, but there were still great mysteries in the behavior of ordinary matter--like superconductivity, for instance. It was only some twenty years later that I woke up to the fact that the battle had been won, probably long before, and that my motivation was no longer to test the underlying equations and ideas, but to understand what is going on. Within the same few years , the molecular biology pioneers convinced us we needed no mysterious "life force" to bring all of life under the same umbrella. Revolutions in geology, in astrophysics, and the remarkable success of the Standard Model in sorting out the fundamental forces and fields, leave us in the enviable position I described above: given any problematic phenomenon, we know where to start, at least. And nothing uncovered in string theory or quantum gravity will make any difference to that starting point.

Is this Horgan's End of Science? Absolutely not. It's just that the most exciting frontier of science no longer lies at the somewhat sophomoric — or quasi-religious — level of the most "fundamental" questions of "what are we made of?" and the like; what needs to be asked is "how did all this delightful complexity arise from the stark simplicity of the fundamental theory?" We have the theory of every thing in any field of science you care to name, and that's about as far as it gets us. If you like, science is now almost universally at the "software" level; the fundamental physicists have given us all the hardware we need, but that doesn't solve the problem, in physics as in every other field. It's a different game, probably a much harder one in fact, as it has often been in the past; but the game is only begun.

PHILIP W. ANDERSON is a Nobel laureate physicist at Princeton and one of the leading theorists on superconductivity. He is the author of A Career in Theoretical Physics, and Economy as a Complex Evolving System.

Robert Aunger

"Is the Central Dogma of biology inviolate?"

In 1957, a few years after he co-discovered the double helix, Francis Crick proposed a very famous hypothesis. It states that "once 'information' has passed into protein it cannot get out again. In more detail, the transfer of information from nucleic acid to nucleic acid, or from nucleic acid to protein may be possible, but transfer from protein to protein, or from protein to nucleic acid is impossible." After it had proven to form the foundation of molecular biology, he later called this hypothesis the "Central Dogma" of biology.

In the last years of the last millennium, Crick's dogma fell. The reason? Direct protein-to-protein information transfer was found to be possible in a class of proteins called "prions." With the aid of a catalyst, prions (short for "proteinaceous infectious particles") cause another molecule of the same class to adopt an infectious shape like their own simply through contact. Thus, prions are an important and only recently discovered mechanism for the inheritance of information through means other than DNA. Such an important discovery merited a recent Nobel Prize for Stanley Prusiner, who doggedly pursued the possibility of a rogue biological entity replicating without the assistance of genes against a back-drop of resistance and disbelief among most of his colleagues. Further testimony to the significance of prions comes from the current BSE crisis in Europe. Now that we know how they work, prions — and the diseases they cause — may begin popping up all over the place.

ROBERT AUNGER is an anthropologist studying cultural evolution, both through the now much-maligned method of fieldwork in nonwestern societies, and the application of theory adapted from evolutionary biology. He is at the Department of Biological Anthropology at the University of Cambridge, and the editor of Darwinizing Culture: The Status of Memetics as a Science.

John Barrow

"How does a slide rule work?"

My vanished question is:"'How does a slide rule work?"' Slide rules were once ubiquitous in labs, classrooms, and the pockets of engineers. They are now as common as dinosaurs; totally replaced by electronic calulators and computers. The interesting question to ponder is: what is it that in the future will do to computers what computers did to slide rules?

JOHN BARROW is a physicist at Cambridge University.. He is the author of The World Within the World, Pi in the Sky, Theories of Everything, The Origins of the Universe (Science Masters Series),The Left Hand of Creation, The Artful Universe, and Impossibility: The Limits of Science and the Science of Limits.

Thomas A. Bass

"The questions that have disappeared are eschatological."

The twentieth century will be remembered as one of the most violent in history. There were two world wars, numerous genocides, and millions of murders conducted in the name of progress. Driving this violence was the urge to find truth or purity. The violence was lit by the refining fire of belief. The redemptive ideal was called national socialism, communism, stalinism, maoism.

Today, these gods have feet of clay, and we mock their pretensions. Global consumerism is the new world order, but global consumerism is not a god. Market capitalism does not ask questions about transcendent meaning. Western democracies, nodding into the sleep of reason, have grown numb with self-congratulation about having won the hot, the cold, and, now, the star wars.

The questions that have disappeared are eschatological. But they have not really disappeared. They are a chtonic force, waiting underground, searching for a new language in which to express themselves. This observation sprang to mind while I was standing in the Place de la Revolution, now known as the Place de la Concorde, awaiting the arrival of the third millennium. During the French revolution this square was so soaked in blood that oxen refused to cross it. On New Year's Eve it was soaked in rain and champagne, as we counted down to a display of fireworks that never materialized. Instead, there was a Ferris wheel, lit alternately in mauve and chartreuse, and some lasers illuminating the Luxor obelisk which today is the square's secular center. No one staring at it knew how to read the hieroglyphics carved on its face, but this obelisk was once a transcendent object, infused with meaning, and so, too, was the guillotine that formerly stood in its place.

THOMAS A. BASS, who currently lives in Paris, is the author of The Eudaemonic Pie, Vietnamerica, The Predictors, and other books.

David Berreby

''How does [fill in the blank] in human affairs relate to the great central theory?''

I do not, of course, mean any particular Great Central Theory. I am referring to the once-pervasive habit of relating everything that had human scale — Chinese history, the Odyssey, your mother's fear of heights — to an all-explaining principle. This principle was set forth in a short shelf of classic works and then worked to a fine filigree by close-minded people masquerading as open-minded people. The precise Great Central Theory might be, as it was in my childhood milieu, the theories of Freud. It might be Marx. It might be Levi-Strauss or, more recently, Foucault. At the turn of the last century, there was a Darwinist version going, promulgated by Francis Galton, Herbert Spencer and their ilk.

These monolithic growths had begun, I suppose, as the answers to specific questions, but then they metastasized; their adherents would expect the great central theory to answer any question. Commitment to a Great Central Theory thus became more a religious act than an intellectual one. And, as with all religions, the worldview of the devout crept into popular culture. (When I was in high school we'd say So-and-So was really anal about his locker or that What's-his-name's parents were really bourgeois.) For decades, this was what intellectual life appeared to be: Commit to an overarching explanation, relate it to everything you experienced, defend it against infidels. Die disillusioned, or, worse, die smug.

So why has this sort of question vanished? My guess is that, broadly speaking, it was a product of the Manichean worldview of the last century. Depression, dictators, war, genocide, nuclear terror — all of these lend themselves to a Yes-or-No, With-Us-or-With-Them, Federation vs. Klingons mindset. We were, to put it simply, all a little paranoid. And paranoids love a Great Key: Use this and see the single underlying cause for what seems to be unrelated and random!

Nowadays the world, though no less dangerous, seems to demand attention to the seperateness of things, the distinctiveness of questions. ''Theories of everything'' are terms physicists use to explain their near-theological concerns, but at the human scale most people care about, where we ask questions like ''why can't we dump the Electoral College?'' or ''How come Mom likes my sister better?'', the Great Central Theory question has vanished with the black-or-white arrangement of the human world.

What's next?

Three possibilities.

One, some new Great Central Theory slouches in; some of the Darwinians think they've got the candidate, and they certainly evince signs of quasi-religious commitment. (For example, as a Freudian would say you doubted Freud because of your neuroses, I have heard Darwinians say I doubted their theories because of an evolved predisposition not to believe the truth. I call this quasi-religious because this move makes the theory impregnable to evidence or new ideas.)

Two, the notion that overarching theory is impossible becomes, itself, a new dogma. I lean toward this prejudice myself but I recognize its dangers. An intellectual life that was all boutiques could be, in its way, as stultifying as a giant one-product factory.

Three, we learn from the mistakes of the last two centuries and insist that our answers always match our questions, and that the distinction between theory and religious belief be maintained.

DAVID BERREBY'S writing about science and culture has appeared in The New York Times Magazine, The New Republic, Slate, The Sciences and many other publications.

Susan Blackmore

"Do we survive death?"

This question was long considered metaphysical, briefly became a scientific question, and has now disappeared again. Victorian intellectuals such as Frederic Myers, Henry Sidgwick and Edmund Gurney founded the Society for Psychical Research in 1882 partly because they realised that the dramatic claims of spiritualist mediums could be empirically tested. They hoped to prove "survival" and thus overturn the growing materialism of the day. Some,
like Faraday, convinced themselves by experiment that the claims were false, and lost interest. Others, like Myers, devoted their entire lives to ultimately inconclusive research. The Society continues to this day, but survival research has all but ceased.

I suggest that no one asks the question any more because the answer seems too obvious. To most scientists it is obviously "No", while to most New Agers and religious people it is obviously "Yes". But perhaps we should. The answer may be obvious (it's "No" — I'm an unreligious scientist) but its implications for living our lives and dealing compassionately with other people are profound.

SUSAN BLACKMORE is a psychologist and ex-parapsychologist, who — when she found no evidence of psychic phenomena — turned her attention to why people believe in them. She is author of several skeptical books on the paranormal and, more recently, The Meme Machine.

Stewart Brand

"How will Americans handle a surplus of leisure?"
"Can the threat of recombinant DNA possibly be contained?"

"How will Americans handle a surplus of leisure?"

That was a brow-furrower in the late '50s and early '60s for social observers and forecasters. Whole books addressed the problem, most of them opining that Americans would have to become very interested in the arts. Turned out the problem never got around to existing, and the same kind of people are worrying now about how Americans will survive the stress of endless multi-tasking.

"Can the threat of recombinant DNA possibly be contained?"

That was the brand new bogey of the mid-'70s. At a famous self regulating conference at Asilomar conference center in California, genetic researchers debated the question and imposed rules (but not "relinquishment") on the lab work. The question was answered: the threat was handily contained, and it was not as much of a threat as feared anyway. Most people retrospectively applaud the original caution. Similar fears and debate now accompany the introduction of Genetically Modified foods and organisms. Maybe it's the same question rephrased, and it will keep being rephrased as long as biotech is making news. Can the threat of frankenfoods possibly be contained? Can the threat of gene-modified children possibly be contained? Can the threat of bioweapons possibly be contained? Can the threat of human life extension possibly be contained?

It won't be a new question until it reaches reflexivity: "Are GM humans really human?"

STEWART BRAND is founder of the Whole Earth Catalog, cofounder of The Well, cofounder of Global Business Network, cofounder and president of The Long Now Foundation. He is the original editor of The Whole Earth Catalog, author of The Media Lab: Inventing the Future at MIT , How Buildings Learn, and The Clock of the Long Now: Time and Responsibility (MasterMinds Series).

Rodney A. Brooks

"What is it that makes something alive?"

With the success of molecular biology explaining the mechanisms of life we have lost sight of the question one level up. We do not have any good answers at a more systems level of what it takes for something to be alive. We can list general necessities for a system to be alive, but we can not predict whether a given configuration of molecules will be alive or not. As evidence that we really do not understand what it takes for something to be alive, we have not been able to build machines that are alive.

Everything else that we understand leads to machines that capitalize on that understanding — machines that fly, machines that run, machines that calculate, machines that make polymers, machines that communicate, machines that listen, machines that play games. We have not built any machines that live.

RODNEY A. BROOKS is director of the MIT Artificial Intelligence Laboratory and Chairman of iRobot Corporation. He builds robots.

David M. Buss

"Do Men and Women Differ Psychologically?"

Psychology for much of the 20^th century was dominated by the view that men and women were psychologically identical. So pervasive was this assumption that research articles in psychology journals prior to the 1970's rarely bothered to report the sex of their study participants. Women and men were understood to be interchangeable. Findings for one sex were presumed to be applicable to the other. Once the American Psychological Association required sex of participants to be reported in published experiments, controversy erupted over whether men and women were psychologically different. The past three decades of empirical research has resolved this issue, at least in delimited domains. Although women and men show great psychological similarity, they also differ in profound ways. They diverge in the sexual desires they express and mating strategies they pursue. They differ in the time they allocate to friends and relentlessness with which they pursue status. They display distinct abilities in reading other's minds, feeling other's feelings, and responding emotionally to specific traumas in their lives. Men opt for a wider range of risky activities, are more prone to violence against others, make sharper in-group versus out-group distinctions, and commit the vast majority of homicides worldwide. The question 'Do men and women differ psychologically?' has been replaced with more interesting questions. In what ways do these sex differences create conflict between men and women? Have the selection pressures that created these differences vanished in the modern world? How can societies premised on equality grapple with the profound psychological divergences of the sexes?

DAVID M. BUSS is Professor of Psychology at the University of Texas, Austin, and author of several books, most recently The Dangerous Passion:  Why Jealousy is as Necessary as Love and Evolutionary Psychology:  The New Science of the Mind , and The Evolution of Desire:  Strategies of Human Mating.  

Jason McCabe Calacanis

"How long before all nations obey the basic principles of the human rights as outlined in the Universal Declaration of Human Rights on December 10th, 1948?"

The distinctive Amnesty International arched sticker, with a burning candle surrounded by a swoosh of barbed wire, seemed to adorn every college dorm-room door, beat up Honda Accord, and office bulletin board when I started college in the late '80s at Fordham University. Human rights was the "in" cause. So, we all joined Amnesty and watched our heroes including Bruce Springsteen, Sting, and Peter Gabriel sing on the "Human Rights Now" tour (brought to you, of course, by Reebok).

As quickly as it took center stage, however, human rights seemed to fall off the map. Somewhere in the mid-90s, something stole our fire and free time, perhaps it was the gold rush years of the Internet or the end of the Cold War. The wild spread of entrepreneurship and capitalism may have carried some democracy along with it. Yet just because people are starting companies and economic markets are opening up doesn't mean that there are fewer tortures, rapes, and murders for political beliefs. (These kinds of false perceptions may stem from giving places like China "Most Favored Nation" status).

Youth inspired by artists created the foundation of Amnesty's success in the '80s, so maybe a vacuum of activist artists is to blame for human rights disappearing from the collective consciousness. Would a homophobic, misogynistic, and violent artist like Eminem ever take a stand for anyone other than himself? Could anyone take him seriously if he did? Britney Spears' fans might not have a problem with her dressing in a thong at the MTV Music Awards but how comfortable would they be if she addressed the issue of the rape, kidnapping, and torture of young women in Sierra Leone?

Of course, you don't have to look around the world to find human-rights abuses. Rodney King and Abner Louima taught us that human rights is an important and pressing issue right in our backyard. (Because of these examples, some narrow-minded individuals may see is as only a race specific issue.) One bright spot in all of this, however, is that the technology that was supposed to create a Big Brother state, like video cameras, is now being used to police Big Brother himself. (Check out witness.org and send them a check — or a video camera — if you have the means.)

Eleanor Roosevelt considered her fight to create the Universal Declaration of Human Rights her greatest accomplishment. How ashamed would she be that 50 years has elapsed since her battle, and now, no one seems to care.

JASON McCABE CALACANIS is Editor and Publisher of Silicon Alley Daily; The Digital Coast Weekly, Silicon Alley Reporter and Chairman CEO, Rising Tide Studios.

William H. Calvin

"Where did the moon go?"

When, every few years, you see a bite taken out of the sun or moon, you ought to remember just how frightening that question used to be. It became clockwork when the right viewpoint was eventually discovered by science (imagining yourself high above the north pole, looking at the shadows cast by the earth and the moon). But there was an intermediate stage of empirical knowledge, when the shaman discovered that the sixth full moon after a prior eclipse had a two-third's chance of being associated with another eclipse. And so when the shaman told people to pray hard the night before, he was soon seen as being on speaking terms with whomever ran the heavens. This helped convert part-time shamen into full-time priests, supported by the community. This can be seen as the entry-level job for philosophers and scientists, who prize the discoveries they can pass on to the next generation, allowing us to see farther, always opening up new questions while retiring old ones. It's like climbing a mountain that keeps providing an even better viewpoint.

WILLIAM H. CALVIN is a neurobiologist at the University of Washington, who writes about brains, evolution, and climate. His recent books are The Cerebral Code, How Brains Think, and (with the linguist Derek Bickerton) Lingua ex Machina.

Andy Clark

"Why Is There Something Instead of Nothing?"

This is a question that the ancients asked, and one that crops up a few times in 20th century philosophical discussions. When it is mentioned, it is usually as an example of a problem that looks to be both deep and in principle insoluble. Unsurprisingly, then, it seems to have fallen by the scientific, cosmological and philosophical waysides. But sometimes I wonder whether it really is insoluble (or senseless), or whether science may one day surprise us by finding an answer.

ANDY CLARK is Professor of Philosophy and Cognitive Science at the University of Sussex, UK. He was previously Director of the Philosophy/Neuroscience/Psychology Program at Washington University in St. Louis. He is the author of Microcognition: Philosophy, Cognitive Science and Parallel Distributed Processing, Associative Engines, and Being There: Putting Brain, Body and World Together Again.

Ann Crittenden

"Is human nature innately good or evil?"

Another question that has fallen into the dustbin of history is this: Is human nature innately good or evil? This became a gripping topic in the late 17th century, as Enlightment thinkers began to challenge the Christian assumption that man was born a fallen creature. It was a great debate while it lasted: original sin vs. tabla rasa and the perfectability of man; Edmund Burke vs. Tom Paine; Dostoyevsky vs. the Russian reformers. But Darwin and Freud undermined the foundations of both sides, by discrediting the very possibility of discussing human nature in moral or teleological terms. Now the debate has been recast as "nature vs. nurture" and in secular scientific circles at least, man is the higher primate -- a beast with distinctly mixed potential.   

ANN CRITTENDEN is an award-winning journalist and author. She was a reporter for The New York Times from 1975 to 1983, where her work on a broad range of economic issues was nominated for the Pulitzer Prize. She is the author of several books inncluding The Price of Motherhood: Why the Most Important Job in the World is Still the Least Valued. Her articles have appeared in numerous magazines, including The Nation, Foreign Affairs, McCall's, Lear's, and Working Woman.

Paul Davies

"How fast is the Earth moving?"

A hundred years ago, one of the most fundamental questions in physical science was: How fast is the Earth moving? Many experiments had been performed to measure the speed of the Earth through space as it orbits the sun, and as the solar system orbits the galaxy. The most famous was conducted in 1887 by Albert Michelson and Edward Morley using an optical interferometer. The result they obtained was... zero. Today, scientists regard the question of the Earth's speed through space as meaningless and misconceived, although many non-scientists still refer to the concept.

Why has the question disappeared? Einstein's theory of relativity, published in 1905, denied any absolute frame of rest in the universe; speed is meaningful only relative to other bodies or physical systems. Ironically, some decades later, it was discovered there is a special frame of reference in the universe defined by the cosmic microwave background radiation, the fading afterglow of the big bang. The Earth sweeps through this radiation at roughly 600 km per second (over a million miles per hour) in the direction of the constellation Leo. This is the closest that modern astronomy gets to the notion of an absolute cosmic velocity.

PAUL DAVIES is an internationally acclaimed physicist, writer and broadcaster, now based in South Australia. Professor Davies is the author of some twenty books, including Other Worlds, God and the New Physics, The Edge of Infinity, The Mind of God, The Cosmic Blueprint, Are We Alone? and About Time. He is the recipient of a Glaxo Science Writers' Fellowship, an Advance Australia Award and a Eureka prize for his contributions to Australian science, and in 1995 he won the prestigious Templeton Prize for his work on the deeper meaning of science.

Richard Dawkins

"As William Blake might have written to a coelacanth: Did he who made the haplochromids make thee?"

Different people on the Edge list seem to have chosen to understand 'questions that have disappeared' in three very different senses:

1. Questions that were once popular but have now been answered
2. Questions that should never have been asked in the first place
3. Questions that have disappeared although they never received a satisfactory answer.

This third meaning is, I suspect, the one intended by the organizer of the forum.  It is the most interesting of the three since it suggests real science that we should now be doing, rather than just raking over the historical coals.

The three meanings are too disparate to bring together easily, but I'll try. The popular question 'Has there been enough time for evolution to take place?'  can now confidently be answered in the affirmative.  It should never have been put in the first place since, self-evidently, we are here. But what is more interesting is that the real question that faces us is almost the exact opposite.  Why is evolution so slow, given that natural selection is so powerful?   Far from there being too little time for evolution to play with, there seems to be too much.

Ledyard Stebbins did a theoretical calculation about an extremely weak selection pressure, acting on a population of mouse-sized animals to favor the largest individuals.  His hypothetical selection pressure was so weak as to be below the threshold of detectability in field sampling studies.  Yet the calculated time to evolve elephant-sized descendants from mouse-sized ancestors was only a few tens of thousands of generations: too short to be detected under most circumstances in the fossil record.  To exaggerate somewhat, evolution could be yo-yo-ing from mouse to elephant, and back again, so fast that the changes could seem instantaneous in the fossil record.

Worse, Stebbins's calculation assumed an exceedingly weak selection pressure.  The real selection pressures measured in the field by Ford and his colleagues on lepidoptera and snails, by Endler and his colleagues on guppies, and by the Grants and their colleagues on the Galapagos finches, are orders of magnitude stronger.  If we fed into the Stebbins calculation a selection pressure as strong as the Grants have measured in the field, it is positively worrying to contemplate how fast evolution could go.  The same conclusion is indirectly suggested by domestic breeding.  We have gone from wolf to Yorkshire terrier in a few centuries, and could presumably go back to something like a wolf in as short a time.

It is indeed the case that evolution on the Galapagos archipelago has been pretty fast, though still nothing like as fast as the measured selection pressures might project.  The islands have been in existence for five million years at the outside, and the whole of their famous endemic fauna has evolved during that time.  But even the Galapagos islands are old compared to Lake Victoria.  In the less than one million years of the lake's brief lifetime, more than 170 species of the genus Haplochromis alone have evolved.

Yet the Coelacanth Latimeria, and the three genera of lungfish, have scarcely changed in hundreds of millions of years.  Surviving Lingula ('lamp shells') are classified in the same genus as their ancestors of 400 million years ago, and could conceivably interbreed with them if introduced through a time machine.  The question that still faces us is this.  How can evolution be both so fast and so leadenly slow?  How can there be so much variance in rates of evolution?  Is stasis just due to stabilizing selection and lack of directional selection?  Or is there something remarkably special going on in the (non) evolution of living fossils?  As William Blake might have written to a coelacanth: Did he who made the haplochromids make thee?

RICHARD DAWKINS is an evolutionary biologist and the Charles Simonyi Professor For The Understanding Of Science at Oxford University; Fellow of New College; author of The Selfish Gene, The Extended Phenotype , The Blind Watchmaker, River out of Eden (ScienceMasters Series), Climbing Mount Improbable, and Unweaving the Rainbow.

Stanislas Dehaene

"The definition of life and consciousness?"

Some scientific questions cannot be resolved, but rather are dissolved, and vanish once we begin to better understand their terms.

This is often the case for "definitional questions". For instance, what is the definition of life? Can we trace a sharp boundary between what is living and what is not living? Is a virus living? Is the entire earth a living organism? It seems that our brain predisposes us to ask questions that require a yes or no answer. Moreover, as scientists, we'd like to keep our mental categories straight and, therefore, we would like to have neat and tidy definitions of the terms we use. However, especially in the biological sciences, the objects of reality do not conform nicely to our categorical expectations. As we delve into research, we begin to realize that what we naively conceived of as a essential category is, in fact, a cluster of loosely bound properties that each need to be considered in turn (in the case of life: metabolism, reproduction, autonomy, homeostasy, etc..). Thus, what was initially considered as a simple question, requiring a straightforward answer, becomes a complex issue or even a whole domain of research. We begin to realize that there is no single answer, but many different answers depending on how one frames the terms of the question. And eventually, the question is simply dropped. It is not longer relevant.

I strongly suspect that one of today's hottest scientific question,s the definition of consciousness, is of this kind. Some scientists seem to believe that what we call consciousness is an essence of reality, a single coherent phenomenon that can be reduced to a single level such as a quantum property of microtubules. Another possibility, however, that consciousness is a cluster of properties that, most of the time, cohere together in awake adult humans. A minimal list probably includes the ability to attend to sensory inputs or internal thoughts, to make them available broadly to multiple cerebral systems, to store them in working memory and in episodic memory, to manipulate them mentally, to act intentionally based on them, and in particular to report them verbally. As we explore the issue empirically, we begin to find many situations (such as visual masking or specific brain lesions) in which those properties break down. The neat question "what is consciousness" dissolves into a myriad of more precise and more fruitful research avenues.

Any biological theory of consciousness, which assumes that consciousness has evolved, implies that "having consciousness" is not an all-or-none property. The biological substrates of consciousness in human adults are probably also present, but only in partial form, in other species, in young children or brain-lesioned patients. It is therefore a partially arbitrary question whether we want to extend the use of the term "consciousness" to them. For instance, several mammals, and even very young human children, show intentional behavior, partially reportable mental states, some working memory ability — but perhaps no theory of mind, and more "encapsulated" mental processes that cannot be reported verbally or even non-verbally. Do they have consciousness, then? My bet is that once a detailed cognitive and neural theory of the various aspects of consciousness is available, the vacuity of this question will become obvious.

STANISLAS DEHAENE, researcher at the Institut National de la Santé, studies cognitive neuropsychology of language and number processing in the human brain; author of The Number Sense: How Mathematical Knowledge Is Embedded In Our Brains.

David Deutsch

"And why?"

"What Questions Have Disappeared...And Why?" Funny you should ask that. "And why? " could itself be the most important question that has disappeared from many fields.

"And why?": in other words, "what is the explanation for what we see happening?" "What is it in reality that brings about the outcome that we predict?" Whenever we fail to take that question seriously enough, we are blinded to gaps in our favoured explanation. And so, when we use that explanation to interpret regularities that we may observe, instead of understanding that the explanation was an assumption in our analysis, we regard it as the inescapable implication of our observations.

"I just can't feel myself split", complained Bryce DeWitt when he first encountered the many-universes interpretation of quantum theory. Then Hugh Everett convinced him that this was the same circular reasoning that Galileo rejected when he explained how the Earth can be in motion even though we observe it to be at rest. The point is, both theories are consistent with that observation. Thanks to Everett, DeWitt and others, the "and why" question began gradually to return to quantum theory, whence it had largely disappeared during the 1930s. I believe that its absence did great harm both in impeding progress and in encouraging all sorts of mystical fads and pseudo-science. But elsewhere, especially in the human philosophies (generally known as social sciences), it is still largely missing. Although behaviourism — the principled refusal to ask "and why?" — is no longer dominant as an explicit ideology, it is still widespread as a psychological attitude in the human philosophies.

Suppose you identified a gene G, and a human behaviour B, and you undertook a study with 1000 randomly chosen people, and the result was that of the 500 people who had G in their genome, 499 did B, while of the 500 who lacked G, 499 failed to do B. You'd conclude, wouldn't you, that G is the predominant cause of B? Obviously there must be other mechanisms involved, but they have little influence on whether a person does B or not. You'd inform the press that all those once-trendy theories that tried to explain B through people's upbringing or culture, or attributed it to the exercise of free will or the logic of the situation or any combination of such factors — were just wrong. You've proved that when people choose to do B, they are at the very least responding to a powerful influence from their genes. And if someone points out that your results are perfectly consistent with B being 100% caused by something other than G (or any other gene), or with G exerting an influence in the direction of not doing B, you will shrug momentarily, and then forget that possibility. Won't you?

DAVID DEUTSCH's research in quantum physics has been influential and highly acclaimed. His papers on quantum computation laid the foundations for that field, breaking new ground in the theory of computation as well as physics, and have triggered an explosion of research efforts worldwide. He is a member of the Centre for Quantum Computation at the Clarendon Laboratory, Oxford University and the author of The Fabric of Reality.

Keith Devlin

"Why can't girls/women do math?"

Heavens, I take a couple of days off from reading email over Christmas and when I next log on already there are over twenty responses to the Edge question! Maybe the question we should all be asking is "Doesn't anyone take time off any more?"

As to questions that have disappeared, as a mathematician I hope we've seen the last of the question "Why can't girls/women do math?" With women now outnumbering men in mathematics programs in most US colleges and universities, that old wives' tale (old husbands' tale?) has surely been consigned to the garbage can. Some recent research at Brown University confirmed what most of us had long suspected: that past (and any remaining present) performance differences were based on cultural stereotyping. (The researchers found that women students performed worse at math tests when they were given in a mixed gender class than when no men were present. No communication was necessary to cause the difference. The sheer presence of men was enough.)

While I was enjoying my offline Christmas, Roger Schank already raised the other big math question: Why do we make such a big deal of math performance and of teaching math to everyone in the first place? But with the educational math wars still raging, I doubt we've
seen the last of that one!

KEITH DEVLIN is a mathematician, writer, and broadcaster living in California. His latest book is The Math Gene: How Mathematical Thinking Evolved and Why Numbers Are Like Gossip.

Denis Dutton

"When will overpopulation create worldwide starvation?"

They cordoned off the area and brought in disposal experts to defuse the bomb, but it turned out to be full of — sawdust. The Population Bomb is truly a dud, although this news and its implications have yet fully to sink into the general consciousness.

Ideas can become so embedded in our outlook that they are hard to shake by rational argument. As a Peace Corps Volunteer working in rural India in the 1960s, I vividly remember being faced with multiple uncertainties about what might work for the modernization of India. There was only one thing I and my fellow development workers could all agree on: India unquestionably would experience mass famine by the 1980s at the latest. For us at the time this notion was an eschatological inevitability and an article of faith.

For 35 years since those days, India has grown in population by over a million souls a month, never failing to feed itself or earn enough to buy the food it needs (sporadic famine conditions in isolated areas, which still happen in India, are always a matter of communications and distribution breakdown).

Like so many of the doomsayers of the twentieth century, we left crucial factors out of our glib calculations. First, we failed to appreciate that people in developing countries will behave exactly like people in the rest of the world: as they improve their standard of living, they have fewer children. In India, the rate of population increase began to turn around in the 1970s, and it has declined since. More importantly, we underestimated the capacity of human intelligence to adapt changing situations.

Broadly speaking, instead of a world population of 25 or 30 billion, which some prophets of the 1960s were predicting, it now looks as though the peak of world population growth might be reached within 25 to 40 years at a maximum of 8.5 billion (just 2.5 billion above the present world population). Even without advances in food technology, the areas of land currently out of agricultural production in the United States and elsewhere will prevent starvation. But genetic technologies will increase the quantities and healthfulness of food, while at the same time making food production much more environmentally friendly. For example, combining gene modification with herbicides will make it possible to produce crops that induce no soil erosion. New varieties will requires less intensive application of nitrogen fertilizers and pesticides. If genetic techniques can control endemic pests, vast areas of Africa could be brought into productive cultivation.

There will be no way to add 2.5 billion people to the planet without environmental costs. Some present difficulties, such as limited supplies of fresh water in Third World localities, will only get worse. But these problems will not be insoluble. Moreover, there is not the slightest chance that population growth will in itself cause famine. What will be fascinating to watch, for those who live long enough to witness it, will be how the world copes with an aging, declining population, once the high-point has been reached.

The steady evaporation of the question, "When will overpopulation create worldwide starvation?", has left a gaping hole in the mental universe of the doomsayers. They have been quick to fill it with anxieties about global warming, cellphones, the ozone hole, and Macdonaldization. There appears to be a hard-wired human propensity to invent threats where they cannot clearly be discovered. Historically, this has been applied to foreign ethnic groups or odd individuals in a small-scale society (the old woman whose witchcraft must have caused village children to die). Today's anxieties focus on broader threats to mankind, where activism can mix fashionable politics with dubious science. In this respect alone, the human race is not about to run out of problems. Fortunately, it also shows no sign of running out of solutions.

DENIS DUTTON, founder and editor of the innovative Web page Arts & Letters Daily (www.cybereditions.com/aldaily/), teaches the philosophy of art at the University of Canterbury, New Zealand and writes widely on aesthetics. He is editor of the journal Philosophy and Literature, published by the Johns Hopkins University Press. Professor Dutton is a director of Radio New Zealand, Inc.

George B. Dyson

"What does the other side of the moon look like?"

This can be elaborated by the following anecdote, from an interview (2.99) with Herbert York:

"Donald Hornig, who was head of PSAC [President's Science Advisory Committee, during the Johnson Administration] was not imaginative. I can give you an example of this. I was very enthusiastic about getting a picture of the other side of the moon. And there were various ways of doing it, sooner or later. And I argued with Hornig about it and he said, 'Why? It looks just like this side.' And it turned out it didn't. But nevertheless, that was it, and that's the real Hornig. 'Why are you so enthused about the other side of the moon? The other side of the moon looks just like this side, why would you be so interested to see it?'"

GEORGE DYSON, a historian among futurists, has been excavating the history and prehistory of the digital revolution going back 300 years. His most recent book is Darwin Among the Machines.

J. Doyne Farmer

"What do these discarded questions tell us?"

The road of knowledge is littered with old questions, but by their very nature, none of them stands out above all others. The diversity of thoughtful responses given on the Edge forum, which just begin to scratch the surface, illustrates how progress happens. The evolution of knowledge is a Schumpterian process of creative destruction, in which weeding out the questions that no longer merit attention is an integral part of formulating better questions that should. Forgetting is a vital part of creation.

Maxwell once worried that the second law of thermodynamics could be violated by a demon who could measure the velocity of individual particles and separate the fast ones from the slow ones, and use this to do work. Charlie Bennet showed that that this is impossible, because to make a measurement the demon has to first put her instruments in a known state.

This involves erasing information. The energy needed to do this is more than can be gained. Thus, the fact that forgetting takes work is essential to the second law of thermodynamics. Why is this relevant? As Gregory Bateson once said, the second law of thermodynamics is the reason that it is easier to mess up a room than it is to clean it. Forgetting is an essential part of the process of creating order. Asking the right questions is the most important part of the creative process. There are lots of people who are good at solving problems, fewer who are good at asking questions.

Around the time I took my qualifying examination in physics, someone showed me the test that Lord Rayleigh took when he graduated as senior wrangler from Cambridge in 1865. I would have failed it. There were no questions on thermodynamics, statistical mechanics, quantum mechanics, nuclear physics, particle physics, condensed matter, or relativity, i.e. no questions covering most of what I had learned.

However, the classical mechanics questions, which comprised most of the bets, were diabolically hard. Their solution involved techniques that are no longer taught, and that a modern physicist would have to work hard to recreate. Of course, in a field like philosophy this would not have surprised me — it just hadn't occurred to me that this was as true for physics as well. The physicists in Rayleigh's generation presumably worked just as hard, and knew just as many things. They just knew different things. After overcoming the shock of how much had seemingly been lost, I rationalized my ignorance with the belief that what I was taught was more useful than what Rayleigh was taught. Whether as a culture or as individuals, to learn new things, we have to forget old things. The notion of what is useful is constantly evolving.

The most important questions evolve through time as people understand little bits and pieces, and view them from different angles in the attempt to solve them. Each question is replaced by a new one that is (hopefully) better framed than its antecedant. Reflecting on those that have been cast aside is like sifting through flotsam on a beach, and asking what it tells us. Is there a common thread that might give us a clue to posing better questions in the future?

When we examine questions such as "What is a vital force?", "How fast is the earth moving?", "Does God exist?", "Have we seen the end of science?", "Has history ended?", "Can machines think?", there are some common threads. One is that we never really understood what these questions meant in the first place. But these questions (to varying degrees) have been useful in helping us to formulate better, more focused questions. We just have to turn loose of our pet ideas, and make a careful distinction between what we know and what we only think we know, and try to be more precise about what we are really asking.

I would be curious to hear more discussion about the common patterns and the conclusions to be drawn from the questions that have disappeared.

J. DOYNE FARMER, one of the pioneers of what has come to be called chaos theory, is McKinsey Professor, Sante Fe, Institute, and the co founder and former co-president of Prediction Company in Santa Fe, New Mexico.

Kenneth Ford

"When will we face another energy crisis, and how will we cope with it?"

This question (or pair of questions) was on everyone's lips in the 1970s, following the oil shortage and lines at gas stations. It stimulated a lot of good thinking and good work on alternative energy sources, renewable energy sources, and energy efficiency. Although this question is still asked by many knowledgeable and concerned people, it has disappeared from the public's radar screen (or, better, television screen). Even the recent escalation of fuel prices and the electricity shortage in California have not lent urgency to thinking ahead about energy.

But we should be asking, we should be worrying, and we should be planning. A real energy crisis is closer now than it was when the question had high currency. The energy-crisis question is only part of a larger question: How is humankind going to deal in the long term with its impact on the physical world we inhabit (of which the exhaustion of fossil fuels is only a part)? Another way to phrase the larger question: Are we going to manage more or less gracefully a transition to a sustainable world, or will eventual sustainability be what's left, willy nilly, after the chaos of unplanned, unanticipated change?

Science will provide no miracles (as the Wall Street Journal, in its justification of inaction, would have us believe), but science can do a lot to ameliorate the dislocations that this century will bring. We need to encourage our public figures to lift their eyes beyond the two-, four-, and six-year time horizons of their jobs.

KENNETH FORD is a retired physicist who teaches at Germantown Friends School in Philadelphia. He is the co-author, with John Wheeler, of Geons, Black Holes, and Quantum Foam: A Life in Physics.

Howard Gardner

"Has History Ended?"

I am going to take slight liberty with your question. With the publication a decade ago of Francis Fukuyama's justly acclaimed article The End Of History, many pundits and non-pundits assumed that historical forces and trends had been spent. The era of the "isms" was at an end; liberal democracy, market forces, and globalization had triumphed; the heavy weight of the past was attenuating around the globe.

At the start of 2001, we are no longer asking "Has History Ended?" History seems all too alive. The events of Seattle challenged the globalization behemoth; the world is no longer beating a path to internet startups; Communist and fascist revivals have emerged in several countries; the historical legacies in areas like the Balkans and the Middle East are as vivid as ever; and, as I noted in response to last year's question, much of Africa is at war. As if to remind us of our naivete, Fidel Castro and Saddam Hussein have been in "office" as long as most Americans can remember. If George II is ignorant of this history, he is likely to see it repeated.

HOWARD GARDNER, the major proponent of the theory of multiple intelligences, is Professor of Education at Harvard University and author of numerous books including The Mind's New Science and Extraordinary Minds: Portraits of Four Exceptional Individuals.

Joel Garreau

"What can government do to help create a better sort of human?"

The moral, intellectual, physical and social improvement of the human race was a hot topic of the Enlightenment. It helped shape the American and French revolutions. Creating the "New Soviet Man" was at the heart of the Russian revolution — that's what justified the violence.

A central theme of Lyndon Johnson's Great Society was not just that human misery could be alleviated. It was that core human problems like crime could be fixed by the government eliminating root causes like want.

That's all gone.

We now barely trust government to teach kids to read.

JOEL GARREAU, the cultural revolution correspondent of The Washington Post, is a student of global culture, values, and change whose current interests range from human networks and the transmission of ideas to the hypothesis that the '90s — like the '50s — set the stage for a social revolution to come. He is the author of the best-selling books Edge City: Life on the New Frontier and The Nine Nations of North America, and a principal of The Edge City Group, which is dedicated to the creation of more liveable and profitable urban areas worldwide.

David Gelernter

"How should adult education work? How do we educate the masses? (That's right, The Masses.)...."

How should adult education work? How do we educate the masses? (That's right, The Masses.) How do we widen the circle of people who love and support great art, great music, great literature? How do we widen the circle of adults who understand the science and engineering that our modern world is built on? How do we rear good American citizens? Or for that matter good German citizens, or Israeli or Danish or Chilean? And if this is the information age, why does the population at large grow worse-informed every year? (Sorry — that last one isn't a question people have stopped asking; they never started.)

These questions have disappeared because in 2001, the "educated elite" never goes anywhere without its quote-marks. Here in America's fancy universities, we used to believe that everyone deserved and ought to have the blessings of education. Today we believe our children should have them — and to make up for that fact, to even the score, we have abolished the phrase. No more "blessings of education." That makes us feel better. Many of us can't say "truth and beauty" without snickering like 10-year-old boys.

But the situation will change, as soon as we regain the presence of mind to start asking these questions again. We have the raw materials on hand for the greatest cultural rebirth in history. We have the money and the technical means. We tend to tell our children nowadays (implicitly) that their goal in life is to get rich, get famous and lord it over the world. We are ashamed to tell them that what they really ought to be is good, brave and true. (In fact I am almost ashamed to type it.) This terrible crisis of confidence we're going through was probably inevitable; at any rate it's temporary, and if we can't summon the courage to tell our children what's right, my guess is that they will figure it out for themselves, and tell us. I'm optimistic.

DAVID GELERNTER, Professor of Computer Science at Yale University and author of Mirror Worlds, The Muse in the Machine, 1939: The Lost World of the Fair, and Drawiing a Life: Surviving the Unabomber.

Brian Goodwin

"Where Does Love Come From?"

What does science have to say about the origins of love in the scheme of things? Not a lot. In fact, it is still virtually a taboo subject, just as consciousness was until very recently. However, since feelings are a major component of consciousness, it seems likely that the ontology of love is now likely to emerge as a significant question in science.

Within Christian culture, as in many other religious traditions, love has its origin as a primal quality of God and so is co-eternal with Him. His creation is an outpouring of this love in shared relationship with beings that participate in the essential creativity of the cosmos. As in the world of Shakespeare and the Renaissance Magi, it is love that makes the world go round and animates all relationships.

This magical view of the world did not satisfy the emerging perspective of Galilean science, which saw relationships in nature as law-like, obeying self-consistent logical principles of order. God may well have created the world, but he did so according to intelligible principles. It is the job of the scientist to identify these and describe them in mathematical form. And so with Newton, love turned into gravity. The rotation of the earth around the sun, and the moon around the earth, was a result of the inverse square law of gravitational attraction. It was not a manifestation of love as an attractive principle between animated beings, however much humanity remained attached to romantic feelings about the full moon. Love was henceforth banished from scientific discourse and the mechanical world-view took over.

Now science itself is changing and mechanical principles are being replaced by more subtle notions of interaction and relationships. Quantum mechanics was the first harbinger of a new holistic world of non-local connectedness in which causality operates in a much more intricate way than conventional mechanism. We now have complexity theory as well, which seeks to understand how emergent properties arise in complex systems such as developing organisms, colonies of social insects, and human brains. Often these properties are not reducible to the behavior of their component parts and their interactions, though there is always consistency between levels: that is, there are no contradictions between the properties of the parts of a complex system and the order that emerges from them. Consciousness appears to be one of these emergent properties. With this recognition, science enters a new realm.

Consciousness involves feelings, or more generally what are called qualia, the experience of qualities such as pain, pleasure, beauty, and ŠŠ. love. This presents us with a major challenge. The scientific principle of consistency between levels in systems requires that feelings emerge from some property of the component parts (e.g., neurones) that is consistent with feeling, experience. But if matter is 'dead', without any feeling, and neurones are just made of this dead matter, even though organized in a complex way, then where do feelings come from ? This is the crunch question which presents us with a hard choice. We can either say that feelings are epiphenomena, illusions that evolution has invented because they are useful for survival. Or we can change our view of matter and ascribe to the basic stuff of reality some elementary component of feeling, sentience, however rudimentary. Of course, we could also take the view that nature is not self-consistent and that miracles are possible; that something can come from nothing, such as feeling from dead, insentient matter, thus returning to the magical world-view of the early renaissance. But if we are to remain scientific, then the choice is between the other two alternatives.

The notion that evolution has invented feelings because they are useful for survival is not a scientific explanation, because it gives no account of how feelings are possible as properties that emerge in the complex systems we call organisms (i.e., consistent emergent properties of life). So we are left with the other hard choice: matter must have some rudimentary property of sentience. This is the conclusion that the mathematician/philosopher A.N. Whitehead came to in his classic, Process and Reality, and it is being proposed as a solution to the Cartesian separation of mind and matter by some contemporary philosophers and scientists. It involves a radical reappraisal of what we call 'reality'. But it does suggest a world in which love exists as something real, in accord with most peoples' experience. And goodness knows, we could do with a little more of it in our fragmented world.

BRIAN GOODWIN is a professor of biology at the Schumacher College, Milton Keynes, and the author of Temporal Organization in Cells and Analytical Physiology, How The Leopard Changed Its Spots: The Evolution of Complexity, and (with Gerry Webster) Form and Transformation: Generative and Relational Principles in Biology. Dr. Goodwin is a member of the Board of Directors of the Sante Fe Institute.

David Haig

"questions that were asked in extinct languages"

All those questions that were asked in extinct languages for which there is no written record.

DAVID HAIG is an evolutionary geneticist/theorist at Harvard who is interested in conflicts and conflict resolution with the genome, with a particular interest in genomic imprinting and relations between parents and offspring. Hiscurrent interests include the evolution of linkage groups and the evolution of viviparity.

Judy Harris

"Do genes influence human behavior?"

This question bit the dust after a brief but busy life; it is entirely a second-half-of the-20th-century question. Had it been asked before the 20th century, it would have been phrased differently: "heredity" instead of "genes." But it wasn't asked back then, because the answer was obvious to everyone. Unfortunately, the answer everyone gave — yes! — was based on erroneous reasoning about ambiguous evidence: the difference in behavior between the pauper and the prince was attributed entirely to heredity. The fact that the two had been reared in very different circumstances, and hence had had very different experiences, was overlooked.

Around the middle of the 20th century, it became politically incorrect and academically unpopular to use the word "heredity"; if the topic came up at all, a euphemism, "nature," was used in its place. The fact that the pauper and the prince had been reared in very different circumstances now came to the fore, and the behavioral differences between them was now attributed entirely to the differences in their experiences. The observation that the prince had many of the same quirks as the king was now blamed entirely on his upbringing. Unfortunately, this answer, too, was based on erroneous reasoning about ambiguous evidence.

That children tend to resemble their biological parents is ambiguous evidence; the fact that such evidence is plentiful — agreeable parents tend to have agreeable kids, aggressive parents tend to have aggressive kids, and so on — does not make it any less ambiguous. The problem is that most kids are reared by their biological parents. The parents have provided both the genes and the home environment, so the kids' heredity and environment are correlated. The prince has inherited not only his father's genes but also his father's palace, his father's footmen, and his father's Lord High Executioner (no reference to living political figures is intended).

To disambiguate the evidence, special techniques are required — ways of teasing apart heredity and environment by controlling the one and varying the other. Such techniques didn't begin to be widely used until the 1970s; their results didn't become widely known and widely accepted until the 1990s. By then so much evidence had piled up that the conclusion (which should have been obvious all along) was incontrovertible: yes, genes do influence human behavior, and so do the experiences children have while growing up.

(I should point out, in response to David Deutsch's contribution to the World Question Center, that no one study, and no one method, can provide an answer to a question of this sort. In the case of genetic influences on behavior, we have converging evidence — studies using a variety of methods all led to the same conclusion and even agreed pretty well on the quantitative details.)

Though the question has been answered, it has left behind a cloud of confusion that might not disappear for some time. The biases of the second half of the 20th century persist: when "dysfunctional" parents are found to have dysfunctional kids, the tendency is still to blame the environment provided by the parents and to overlook the fact that the parents also provided the genes.

Some would argue that this bias makes sense. After all, they say, we know how the environment influences behavior. How the genes influence behavior is still a mystery — a question for the 21st century to solve. But they are wrong. They know much less than they think they know about how the environment influences behavior.

The 21st century has two important questions to answer. How do genes influence human behavior? How is human behavior influenced by the experiences a child has while growing up?

JUDITH RICH HARRIS is a writer and developmental psychologist; co-author of The Child: A Contemporary View Of Development; winner of the 1997 George A. Miller Award for an outstanding article in general psychology, and author of The Nurture Assumption: Why Children Turn Out The Way They Do.

Marc D. Hauser

"Do animals have thoughts?"

The reason this question is dead is because traditional Skinnerianism, which viewed rats and pigeons as furry and feathered black boxes, guided by simple principles of reinforcement and punishment, is theoretically caput. It can no longer account for the extraordinary things that animals do, spontaneously.

Thus, we now know that animals form cognitive maps of their environment, compute numerosities, represent the relationships among individuals in their social group, and most recently, have some understanding of what others know.

The questions for the future, then, are not "Do animals think?", but "What precisely do they think about, and to what extent do their thoughts differ from our own?"

MARC D. HAUSER is an evolutionary psychologist, and a professor at Harvard University where he is a fellow of the Mind, Brain, and Behavior Program. He is a professor in the departments of Anthropology and Psychology, as well as the Program in Neurosciences. He is the author of The Evolution of Communication, and Wild Minds: