17.

The Marriage of Scepticism and Wonder

Nothing is too wonderful to be true.

Remark attributed to Michael Faraday (1791-1867)

Insight, untested and unsupported, is an insufficient guarantee of truth.

Bertrand Russell, Mysticism and Logic Mysticism and Logic (1929) (1929)

When we are asked to swear in courts of law that we will tell 'the truth, the whole truth, and nothing but the truth', we are being asked the impossible. It is simply beyond our powers. Our memories are fallible; even scientific truth is merely an approximation; and we are ignorant about nearly all of the Universe. Nevertheless, a life may depend on our testimony. To swear to tell the truth, the whole truth, and nothing but the truth to the limit of our abilities to the limit of our abilities is a fair request. Without the qualifying phrase, though, it's simply out of touch. But such a qualification, however consonant with human reality, is unacceptable to any legal system. If everyone tells the truth only to a degree determined by individual judgement, then incriminating or awkward facts might be withheld, events shaded, culpability hidden, responsibility evaded, and justice denied. So the law strives for an impossible standard of accuracy, and we do the best we can. is a fair request. Without the qualifying phrase, though, it's simply out of touch. But such a qualification, however consonant with human reality, is unacceptable to any legal system. If everyone tells the truth only to a degree determined by individual judgement, then incriminating or awkward facts might be withheld, events shaded, culpability hidden, responsibility evaded, and justice denied. So the law strives for an impossible standard of accuracy, and we do the best we can.

In the jury selection process, the court needs to be rea.s.sured that the verdict will be based on evidence. It makes heroic efforts to weed out bias. It is aware of human imperfection. Does the potential juror personally know the district attorney, or the prosecutor, or the defence attorney? What about the judge or the other jurors? Has she formed an opinion about this case not from the facts laid out in court but from pre-trial publicity? Will she a.s.sign evidence from police officers greater or lesser weight than evidence from witnesses for the defence? Is she biased against the defendant's ethnic group? Does the potential juror live in the neighbourhood where the crimes were committed, and might that influence her judgement? Does she have a scientific background about matters on which expert witnesses will testify? (This is often a count against her.) Are any of her relatives or close family members employed in law enforcement or criminal law? Has she herself ever had any run-ins with police that might influence her judgement in the trial? Was any close friend or relative ever arrested on a similar charge?

The American system of jurisprudence recognizes a wide range of factors, predispositions, prejudices and experiences that might cloud our judgement, or affect our objectivity, sometimes even without our knowing it. It goes to great, perhaps even extravagant, lengths to safeguard the process of judgement in a criminal trial from the human weaknesses of those who must decide on innocence or guilt. Even then, of course, the process sometimes fails.

Why would we settle for anything less when interrogating the natural world, or when attempting to decide on vital matters of politics, economics, religion and ethics?

If it is to be applied consistently, science imposes, in exchange for its manifold gifts, a certain onerous burden: we are enjoined, no matter how uncomfortable it might be, to consider ourselves ourselves and our cultural inst.i.tutions scientifically and not to accept uncritically whatever we're told; to surmount as best we can our hopes, conceits and unexamined beliefs; to view ourselves as we really are. Can we conscientiously and courageously follow planetary motion or bacterial genetics wherever the search may lead, but declare the origin of matter or human behaviour off-limits? Because its explanatory power is so great, once you get the hang of scientific reasoning you're eager to apply it everywhere. However, in the course of looking deeply within ourselves, we may challenge notions that give comfort before the terrors of the world. I'm aware that some of the discussion in, say, the preceding chapter may have such a character. and our cultural inst.i.tutions scientifically and not to accept uncritically whatever we're told; to surmount as best we can our hopes, conceits and unexamined beliefs; to view ourselves as we really are. Can we conscientiously and courageously follow planetary motion or bacterial genetics wherever the search may lead, but declare the origin of matter or human behaviour off-limits? Because its explanatory power is so great, once you get the hang of scientific reasoning you're eager to apply it everywhere. However, in the course of looking deeply within ourselves, we may challenge notions that give comfort before the terrors of the world. I'm aware that some of the discussion in, say, the preceding chapter may have such a character.

When anthropologists survey the thousands of distinct cultures and ethnicities that comprise the human family, they are struck by how few features there are that are givens, always present no matter how exotic the society. There are, for example, cultures - the Ik of Uganda is one - where all Ten Commandments seem to be systematically, inst.i.tutionally ignored. There are societies that abandon their old and their newborn, that eat their enemies, that use seash.e.l.ls or pigs or young women for money. But they all have a strong incest taboo, they all use technology, and almost all believe in a supernatural world of G.o.ds and spirits, often connected with the natural environment they inhabit and the well-being of the plants and animals they eat. (The ones with a supreme G.o.d who lives in the sky tend to be the most ferocious - torturing their enemies for example. But this is a statistical correlation only; the causal link has not been established, although speculations naturally present themselves.) In every such society, there is a cherished world of myth and metaphor which co-exists with the workaday world. Efforts to reconcile the two are made, and any rough edges at the joints tend to be off-limits and ignored. We compartmentalize. Some scientists do this too, effortlessly stepping between the sceptical world of science and the credulous world of religious belief without skipping a beat. Of course, the greater the mismatch between these two worlds, the more difficult it is to be comfortable, with untroubled conscience, with both.

In a life short and uncertain, it seems heartless to do anything that might deprive people of the consolation of faith when science cannot remedy their anguish. Those who cannot bear the burden of science are free to ignore its precepts. But we cannot have science in bits and pieces, applying it where we feel safe and ignoring it where we feel threatened - again, because we are not wise enough to do so.

Except by sealing the brain off into separate air-tight compartments, how is it possible to fly in airplanes, listen to the radio or take antibiotics while holding that the Earth is around 10,000 years old or that all Sagittarians are gregarious and affable?

Have I ever heard a sceptic wax superior and contemptuous? Certainly. I've even sometimes heard, to my retrospective dismay, that unpleasant tone in my own voice. There are human imperfections on both sides of this issue. Even when it's applied sensitively, scientific scepticism may come across as arrogant, dogmatic, heartless and dismissive of the feelings and deeply held beliefs of others. And, it must be said, some scientists and dedicated sceptics apply this tool as a blunt instrument, with little finesse. Sometimes it looks as if the sceptical conclusion came first, that contentions were dismissed before, not after, the evidence was examined. All of us cherish our beliefs. They are, to a degree, self-defining. When someone comes along who challenges our belief system as insufficiently well based - or who, like Socrates, merely asks embarra.s.sing questions that we haven't thought of, or demonstrates that we've swept key underlying a.s.sumptions under the rug - it becomes much more than a search for knowledge. It feels like a personal a.s.sault.

The scientist who first proposed to consecrate doubt as a prime virtue of the inquiring mind made it clear that it was a tool and not an end in itself. Rene Descartes wrote, I did not imitate the sceptics who doubt only for doubting's sake, and pretend to be always undecided; on the contrary, my whole intention was to arrive at a certainty, and to dig away the drift and the sand until I reached the rock or the clay beneath.

In the way that scepticism is sometimes applied to issues of public concern, there is is a tendency to belittle, to condescend, to ignore the fact that, deluded or not, supporters of superst.i.tion and pseudoscience are human beings with real feelings, who, like the sceptics, are trying to figure out how the world works and what our role in it might be. Their motives are in many cases consonant with science. If their culture has not given them all the tools they need to pursue this great quest, let us temper our criticism with kindness. None of us comes fully equipped. a tendency to belittle, to condescend, to ignore the fact that, deluded or not, supporters of superst.i.tion and pseudoscience are human beings with real feelings, who, like the sceptics, are trying to figure out how the world works and what our role in it might be. Their motives are in many cases consonant with science. If their culture has not given them all the tools they need to pursue this great quest, let us temper our criticism with kindness. None of us comes fully equipped.

Clearly there are limits to the uses of scepticism. There is some cost-benefit a.n.a.lysis which must be applied, and if the comfort, consolation and hope delivered by mysticism and superst.i.tion is high, and the dangers of belief comparatively low, should we not keep our misgivings to ourselves? But the issue is tricky. Imagine that you enter a big-city taxicab and the moment you get settled in the driver begins a harangue about the supposed iniquities and inferiorities of another ethnic group. Is your best course to keep quiet, bearing in mind that silence conveys a.s.sent? Or is it your moral responsibility to argue with him, to express outrage, even to leave the cab - because you know that every silent a.s.sent will encourage him next time, and every vigorous dissent will cause him next time to think twice? Likewise, if we offer too much silent a.s.sent about mysticism and superst.i.tion - even when it seems to be doing a little good - we abet a general climate in which scepticism is considered impolite, science tiresome, and rigorous thinking somehow stuffy and inappropriate. Figuring out a prudent balance takes wisdom.

The Committee for the Scientific Investigation of Claims of the Paranormal is an organization of scientists, academics, magicians and others dedicated to sceptical scrutiny of emerging or fullblown pseudosciences. It was founded by the University of Buffalo philosopher Paul Kurtz in 1976. I've been affiliated with it since its beginning. Its acronym, CSICOP, is p.r.o.nounced 'sci-cop' - as if it's an organization of scientists performing a police function. Those wounded by CSICOP's a.n.a.lyses sometimes make just such a complaint: it's hostile to every new idea, they say, will go to absurd lengths in its knee-jerk debunking, is a vigilante organization, a New Inquisition, and so on.

CSICOP is is imperfect. In certain cases such a critique is to some degree justified. But from my point of view CSICOP serves an important social function as a well-known organization to which media can apply when they wish to hear the other side of the imperfect. In certain cases such a critique is to some degree justified. But from my point of view CSICOP serves an important social function as a well-known organization to which media can apply when they wish to hear the other side of the story, especially when some amazing claim to pseudoscience is adjudged newsworthy. It used to be (and for much of the global news media it still is) that every levitating guru, visiting alien, channeller and faith-healer, when covered by the media, would be treated nonsubstantively and uncritically. There would be no inst.i.tutional memory at the television studio or newspaper or magazine about other, similar claims previously shown to be scams and bamboozles. CSICOP represents a counterbalance, although not yet nearly a loud enough voice, to the pseudoscience gullibility that seems second nature to so much of the media. story, especially when some amazing claim to pseudoscience is adjudged newsworthy. It used to be (and for much of the global news media it still is) that every levitating guru, visiting alien, channeller and faith-healer, when covered by the media, would be treated nonsubstantively and uncritically. There would be no inst.i.tutional memory at the television studio or newspaper or magazine about other, similar claims previously shown to be scams and bamboozles. CSICOP represents a counterbalance, although not yet nearly a loud enough voice, to the pseudoscience gullibility that seems second nature to so much of the media.

One of my favourite cartoons shows a fortune-teller scrutinizing the mark's palm and gravely concluding, 'You are very gullible.' CSICOP publishes a bi-monthly periodical called The Skeptical Inquirer. The Skeptical Inquirer. On the day it arrives, I take it home from the office and pore through its pages, wondering what new misunderstandings will be revealed. There's always another bamboozle that I never thought of. Crop circles! Aliens have come and made perfect circles and mathematical messages ... in wheat! Who would have thought it? So unlikely an artistic medium. Or they've come and eviscerated cows - on a large scale, systematically. Farmers are furious. At first, I'm impressed by the inventiveness of the stories. But then, on more sober reflection, it always strikes me how dull and routine these accounts are; what a compilation of unimaginative stale ideas, chauvinisms, hopes and fears dressed up as facts. The contentions, from this point of view, are suspect on their face. That's all they can conceive the extraterrestrials doing... making circles in wheat? What a failure of the imagination! With every issue, another facet of pseudoscience is revealed and criticized. On the day it arrives, I take it home from the office and pore through its pages, wondering what new misunderstandings will be revealed. There's always another bamboozle that I never thought of. Crop circles! Aliens have come and made perfect circles and mathematical messages ... in wheat! Who would have thought it? So unlikely an artistic medium. Or they've come and eviscerated cows - on a large scale, systematically. Farmers are furious. At first, I'm impressed by the inventiveness of the stories. But then, on more sober reflection, it always strikes me how dull and routine these accounts are; what a compilation of unimaginative stale ideas, chauvinisms, hopes and fears dressed up as facts. The contentions, from this point of view, are suspect on their face. That's all they can conceive the extraterrestrials doing... making circles in wheat? What a failure of the imagination! With every issue, another facet of pseudoscience is revealed and criticized.

And yet, the chief deficiency I see in the sceptical movement is in its polarization: Us v. Them - the sense that we we have a monopoly on the truth; that those other people who believe in all these stupid doctrines are morons; that if you're sensible, you'll listen to us; and if not, you're beyond redemption. This is unconstructive. It does not get the message across. It condemns the sceptics to permanent minority status; whereas, a compa.s.sionate approach that from the beginning acknowledges the human roots of pseudoscience and superst.i.tion might be much more widely accepted. have a monopoly on the truth; that those other people who believe in all these stupid doctrines are morons; that if you're sensible, you'll listen to us; and if not, you're beyond redemption. This is unconstructive. It does not get the message across. It condemns the sceptics to permanent minority status; whereas, a compa.s.sionate approach that from the beginning acknowledges the human roots of pseudoscience and superst.i.tion might be much more widely accepted.

If we understand this, then of course we feel the uncertainty and pain of the abductees, or those who dare not leave home without consulting their horoscopes, or those who pin their hopes on crystals from Atlantis. And such compa.s.sion for kindred spirits in a common quest also works to make science and the scientific method less off-putting, especially to the young.

Many pseudoscientific and New Age belief systems emerge out of dissatisfaction with conventional values and perspectives and are therefore themselves a kind of scepticism. (The same is true of the origins of most religions.) David Hess (in Science and the New Age) Science and the New Age) argues that argues that

the world of paranormal beliefs and practices cannot be reduced to cranks, crackpots, and charlatans. A large number of sincere people are exploring alternative approaches to questions of personal meaning, spirituality, healing, and paranormal experience in general. To the sceptic, their quest may ultimately rest on a delusion, but debunking is hardly likely to be an effective rhetorical device for their rationalist project of getting [people] to recognize what appears to the sceptic as mistaken or magical thinking.

... [T]he sceptic might take a clue from cultural anthropology and develop a more sophisticated scepticism by understanding alternative belief systems from the perspective of the people who hold them and by situating these beliefs in their historical, social, and cultural contexts. As a result, the world of the paranormal may appear less as a silly turn toward irrationalism and more as an idiom through which segments of society express their conflicts, dilemmas, and ident.i.ties...

To the extent that sceptics have a psychological or sociological theory of New Age beliefs, it tends to be very simplistic: paranormal beliefs are 'comforting' to people who cannot handle the reality of an atheistic universe, or their beliefs are the product of an irresponsible media that is not encouraging the public to think critically...

But Hess's just criticism promptly deteriorates into complaints that parapsychologists 'have had their careers ruined by sceptical colleagues', and that sceptics exhibit 'a kind of religious zeal to defend the materialistic and atheistic world view that smacks of what has been called "scientific fundamentalism" or "irrational rationalism" '. This is a common but to me deeply mysterious - indeed, occult - complaint. Again, we know a great deal about the existence and properties of matter. If a given phenomenon can already be plausibly understood in terms of matter and energy, why should we hypothesize that something else, something for which there is as yet no other good evidence, is responsible? Yet the complaint persists: sceptics won't accept that there's an invisible fire-breathing dragon in my garage because they're all atheistic materialists.

In Science in the New Age, Science in the New Age, scepticism is discussed, but it is not understood, and it is certainly not practised. All sorts of paranormal claims are quoted, sceptics are 'deconstructed', but you can never learn from reading it that there are ways to decide whether New Age and parapsychological claims to knowledge are promising or false. It's all, as in many postmodernist texts, a matter of how strongly people feel and what their biases may be. scepticism is discussed, but it is not understood, and it is certainly not practised. All sorts of paranormal claims are quoted, sceptics are 'deconstructed', but you can never learn from reading it that there are ways to decide whether New Age and parapsychological claims to knowledge are promising or false. It's all, as in many postmodernist texts, a matter of how strongly people feel and what their biases may be.

Robert Anton Wilson (in The New Inquisition: Irrational Rationalism and the Citadel of Science, The New Inquisition: Irrational Rationalism and the Citadel of Science, 1986) describes sceptics as the 'New Inquisition'. But to my knowledge no sceptic compels belief. Indeed, on most TV doc.u.mentaries and talk shows, sceptics get short shrift and almost no air time. All that's happening is that some doctrines and methods are being criticized - at the worst, ridiculed - in magazines like 1986) describes sceptics as the 'New Inquisition'. But to my knowledge no sceptic compels belief. Indeed, on most TV doc.u.mentaries and talk shows, sceptics get short shrift and almost no air time. All that's happening is that some doctrines and methods are being criticized - at the worst, ridiculed - in magazines like The Skeptical Inquirer The Skeptical Inquirer with circulations of a few tens of thousands. New Agers are not much, as in earlier times, being called up before criminal tribunals, nor whipped for having visions, and they are certainly not being burned at the stake. Why fear a little criticism? Aren't they interested to see how well their beliefs hold up against the best counterarguments the sceptics can muster? with circulations of a few tens of thousands. New Agers are not much, as in earlier times, being called up before criminal tribunals, nor whipped for having visions, and they are certainly not being burned at the stake. Why fear a little criticism? Aren't they interested to see how well their beliefs hold up against the best counterarguments the sceptics can muster?

Perhaps one per cent of the time, someone who has an idea that smells, feels and looks indistinguishable from the usual run of pseudoscience will turn out to be right. Maybe some undiscovered reptile left over from the Cretaceous period will indeed be found in Loch Ness or the Congo Republic; or we will find artefacts of an advanced, non-human species elsewhere in the solar system. At the time of writing there are three claims in the ESP field which, in my opinion, deserve serious study: (1) that by thought alone humans can (barely) affect random number generators in computers; (2) that people under mild sensory deprivation can receive thoughts or images 'projected' at them; and (3) that young children sometimes report the details of a previous life, which upon checking turn out to be accurate and which they could not have known about in any other way than reincarnation. I pick these claims not because I think they're likely to be valid (I don't), but as examples of contentions that in Loch Ness or the Congo Republic; or we will find artefacts of an advanced, non-human species elsewhere in the solar system. At the time of writing there are three claims in the ESP field which, in my opinion, deserve serious study: (1) that by thought alone humans can (barely) affect random number generators in computers; (2) that people under mild sensory deprivation can receive thoughts or images 'projected' at them; and (3) that young children sometimes report the details of a previous life, which upon checking turn out to be accurate and which they could not have known about in any other way than reincarnation. I pick these claims not because I think they're likely to be valid (I don't), but as examples of contentions that might might be true. The last three have at least some, although still dubious, experimental support. Of course, I could be wrong. be true. The last three have at least some, although still dubious, experimental support. Of course, I could be wrong.

In the middle 1970s an astronomer I admire put together a modest manifesto called 'Objections to Astrology' and asked me to endorse it. I struggled with his wording, and in the end found myself unable to sign, not because I thought astrology has any validity whatever, but because I felt (and still feel) that the tone of the statement was authoritarian. It criticized astrology for having origins shrouded in superst.i.tion. But this is true as well for religion, chemistry, medicine and astronomy, to mention only four. The issue is not what faltering and rudimentary knowledge astrology came from, but what is its present validity. Then there was speculation on the psychological motivations of those who believe in astrology. These motivations - for example, the feeling of powerlessness in a complex, troublesome and unpredictable world - might explain why astrology is not generally given the sceptical scrutiny it deserves, but is quite peripheral to whether it works.

The statement stressed that we can think of no mechanism by which astrology could work. This is certainly a relevant point but by itself it's unconvincing. No mechanism was known for continental drift (now subsumed in plate tectonics) when it was proposed by Alfred Wegener in the first quarter of the twentieth century to explain a range of puzzling data in geology and palaeontology. (Ore-bearing veins of rocks and fossils seemed to run continuously from eastern South America to West Africa; were the two continents once touching and the Atlantic Ocean new to our planet?) The notion was roundly dismissed by all the great geophysicists, who were certain that continents were fixed, not floating on anything, and therefore unable to 'drift'. Instead, the key twentieth-century idea in geophysics turns out to be plate tectonics; we now understand that continental plates do indeed float and 'drift' (or better, are carried by a kind of conveyor belt driven by the great heat engine of the Earth's interior), and all those great geophysicists were simply wrong. Objections to pseu-doscience on the grounds of unavailable mechanism can be mistaken - although if the contentions violate well-established laws of physics, such objections of course carry great weight.

Many valid criticisms of astrology can be formulated in a few sentences: for example, its acceptance of precession of the equinoxes in announcing an 'Age of Aquarius' and its rejection of precession of the equinoxes in casting horoscopes; its neglect of atmospheric refraction; its list of supposedly significant celestial objects that is mainly limited to naked eye objects known to Ptolemy in the second century, and that ignores an enormous variety of new astronomical objects discovered since (where is the astrology of near-Earth asteroids?); inconsistent requirements for detailed information on the time as compared to the lat.i.tude and longitude of birth; the failure of astrology to pa.s.s the identical-twin test; the major differences in horoscopes cast from the same birth information by different astrologers; and the absence of demonstrated correlation between horoscopes and such psychological tests as the Minnesota Multiphasic Personality Inventory.

What I would have signed is a statement describing and refuting the princ.i.p.al tenets of astrological belief. Such a statement would have been far more persuasive than what was actually circulated and published. But astrology, which has been with us for four thousand years or more, today seems more popular than ever. At least a quarter of all Americans, according to opinion polls, 'believe' in astrology. A third think Sun-sign astrology is 'scientific'. The fraction of schoolchildren believing in astrology rose from 40 per cent to 59 per cent between 1978 and 1984. There are perhaps ten times more astrologers than astronomers in the United States. In France there are more astrologers than Roman Catholic clergy. No stuffy dismissal by a gaggle of scientists makes contact with the social needs that astrology - no matter how invalid it is - addresses, and science does not.

As I've tried to stress, at the heart of science is an essential balance between two seemingly contradictory att.i.tudes - an openness to new ideas, no matter how bizarre or counterintuitive, and the most ruthlessly sceptical scrutiny of all ideas, old and new. This is how deep truths are winnowed from deep nonsense. The collective enterprise of creative thinking and and sceptical thinking, working together, keeps the field on track. Those two seemingly contradictory att.i.tudes are, though, in some tension. sceptical thinking, working together, keeps the field on track. Those two seemingly contradictory att.i.tudes are, though, in some tension.

Consider this claim: as I walk along, time - as measured by my wrist.w.a.tch or my ageing process - slows down. Also, I shrink in the direction of motion. Also, I get more ma.s.sive. Who has ever witnessed such a thing? It's easy to dismiss it out of hand. Here's another: matter and antimatter are all the time, throughout the universe, being created from nothing. Here's a third: once in a very very great while, your car will spontaneously ooze through the brick wall of your garage and be found the next morning on the street. They're all absurd! But the first is a statement of special relativity, and the other two are consequences of quantum mechanics (vacuum fluctuations and barrier tunnelling,* they're called). Like it or not, that's the way the world is. If you insist it's ridiculous, you'll be forever closed to some of the major findings on the rules that govern the Universe. great while, your car will spontaneously ooze through the brick wall of your garage and be found the next morning on the street. They're all absurd! But the first is a statement of special relativity, and the other two are consequences of quantum mechanics (vacuum fluctuations and barrier tunnelling,* they're called). Like it or not, that's the way the world is. If you insist it's ridiculous, you'll be forever closed to some of the major findings on the rules that govern the Universe.

[* The average waiting time per stochastic ooze is much much longer than the age of the Universe since the Big Bang. But, however improbable, in principle it might happen tomorrow.] longer than the age of the Universe since the Big Bang. But, however improbable, in principle it might happen tomorrow.]

If you're only sceptical, then no new ideas make it through to you. You never learn anything. You become a crochety misanthrope convinced that nonsense is ruling the world. (There is, of course, much data to support you.) Since major discoveries in the borderlines of science are rare, experience will tend to confirm your grumpiness. But every now and then a new idea turns out to be on the mark, valid and wonderful. If you're too resolutely and uncompromisingly sceptical, you're going to miss (or resent) the transforming discoveries in science, and either way you will be obstructing understanding and progress. Mere scepticism is not enough.

At the same time, science requires the most vigorous and uncompromising scepticism, because the vast majority of ideas are simply wrong, and the only way to winnow the wheat from the chaff is by critical experiment and a.n.a.lysis. If you're open to the point of gullibility and have not a microgram of sceptical sense in you, then you cannot distinguish the promising ideas from the worthless ones. Uncritically accepting every proffered notion, idea and hypothesis is tantamount to knowing nothing. Ideas contradict one another; only through sceptical scrutiny can we decide among them. Some ideas really are better than others.

The judicious mix of these two modes of thought is central to the success of science. Good scientists do both. On their own, talking to themselves, they churn up many new ideas, and criticize them systematically. Most of the ideas never make it to the outside world. Only those that pa.s.s a rigorous self-filtration make it out to be criticized by the rest of the scientific community.

Because of this dogged mutual and self-criticism, and the proper reliance on experiment as the arbiter between contending hypotheses, many scientists tend to be diffident about describing their own sense of wonder at the dawning of a wild surmise. This is a pity, because these rare exultant moments demystify and humanize the scientific endeavour.

No one can be entirely open or completely sceptical. We all must draw the line somewhere.* An ancient Chinese proverb advises, 'Better to be too credulous than too sceptical', but this is from an extremely conservative society in which stability was much more prized than freedom and where the rulers had a powerful vested interest in not being challenged. Most scientists, I believe, would say, 'Better to be too sceptical than too credulous'. But neither is easy. Responsible, thoroughgoing, rigorous scepticism requires a hardnosed habit of thought that takes practice and training to master. Credulity - I think a better word here is 'openness' or 'wonder' - does not come easily either. If we really are to be open to counterintuitive ideas in physics or social organization or anything else, we must grasp those ideas. It means nothing to be open to a proposition we don't understand.

[* And in some cases scepticism would be simply silly, as for example in learning to spell.]

Both scepticism and wonder are skills that need honing and practice. Their harmonious marriage within the mind of every schoolchild ought to be a princ.i.p.al goal of public education. I'd love to see such a domestic felicity portrayed in the media, television especially: a community of people really working the mix - full of wonder, generously open to every notion, dismissing nothing except for good reason, but at the same time, and as second nature, demanding stringent standards of evidence; and these standards applied with at least as much rigour to what they hold dear as to what they are tempted to reject with impunity.

18.

The Wind Makes Dust

[T]he wind makes dust because it intends to blow, taking away our footprints.

Specimens of Bushmen Folklore, W.H.I. Bleek and L.C. Lloyd, collectors, L.C. Lloyd, editor (1911)

[E]very time a savage tracks his game he employs a minuteness of observation, and an accuracy of inductive and deductive reasoning which, applied to other matters, would a.s.sure some reputation as a man of science... [T]he intellectual labour of a 'good hunter or warrior' considerably exceeds that of an ordinary Englishman.

Thomas H. Huxley, Collected Essays, Collected Essays, Volume II, Darwiniana: Essays Darwiniana: Essays (London: Macmillan, 1907), pp. 175-6 [from 'Mr Darwin's Critics' (1871)]

Why should so many people find science hard to learn and hard to teach? I've tried to suggest some of the reasons - its precision, its counterintuitive and disquieting aspects, its prospects of misuse, its independence of authority, and so on. But is there something deeper? Alan Cromer is a physics professor at Northeastern University in Boston who was surprised to find so many students unable to grasp the most elementary concepts in his physics cla.s.s. In Uncommon Sense: The Heretical Nature of Science Uncommon Sense: The Heretical Nature of Science (1993), Cromer proposes that science is difficult because it's new. We, a species that's a few hundred thousand years old, discovered the method of science only a few centuries ago, he says. Like writing, which is only a few millennia old, we haven't gotten the hang of it yet - or at least not without very serious and attentive study. (1993), Cromer proposes that science is difficult because it's new. We, a species that's a few hundred thousand years old, discovered the method of science only a few centuries ago, he says. Like writing, which is only a few millennia old, we haven't gotten the hang of it yet - or at least not without very serious and attentive study.

Except for an unlikely concatenation of historical events, he suggests, we would never have invented science: This hostility to science, in the face of its obvious triumphs and benefits, is ... evidence that it is something outside the mainstream of human development, perhaps a fluke.

Chinese civilization invented movable type, gunpowder, the rocket, the magnetic compa.s.s, the seismograph, and systematic observations and chronicles of the heavens. Indian mathematicians invented the zero, the key to comfortable arithmetic and therefore to quant.i.tative science. Aztec civilization developed a far better calendar than that of the European civilization that inundated and destroyed it; they were better able, and for longer periods into the future, to predict where the planets would be. But none of these civilizations, Cromer argues, had developed the sceptical, inquiring, experimental method of science. All of that came out of ancient Greece:

The development of objective thinking by the Greeks appears to have required a number of specific cultural factors. First was the a.s.sembly, where men first learned to persuade one another by means of rational debate. Second was a maritime economy that prevented isolation and parochialism. Third was the existence of a widespread Greek-speaking world around which travelers and scholars could wander. Fourth was the existence of an independent merchant cla.s.s that could hire its own teachers. Fifth was the Iliad Iliad and the and the Odyssey, Odyssey, literary masterpieces that are themselves the epitome of liberal rational thinking. Sixth was a literary religion not dominated by priests. And seventh was the persistence of these factors for 1,000 years. literary masterpieces that are themselves the epitome of liberal rational thinking. Sixth was a literary religion not dominated by priests. And seventh was the persistence of these factors for 1,000 years.

That all these factors came together in one great civilization is quite fortuitous; it didn't happen twice.

I'm sympathetic to part of this thesis. The ancient lonians were the first we know of to argue systematically that laws and forces of Nature, rather than G.o.ds, are responsible for the order and even the existence of the world. As Lucretius summarized their views, 'Nature free at once and rid of her haughty lords is seen to do all things spontaneously of herself without the meddling of the G.o.ds.' Except for the first week of introductory philosophy courses, though, the names and notions of the early lonians are almost never mentioned in our society. Those who dismiss the G.o.ds tend to be forgotten. We are not anxious to preserve the memory of such sceptics, much less their ideas. Heroes who try to explain the world in terms of matter and energy may have arisen many times in many cultures, only to be obliterated by the priests and philosophers in charge of the conventional wisdom, as the Ionian approach was almost wholly lost after the time of Plato and Aristotle. With many cultures and many experiments of this sort, it may be that only on rare occasions does the idea take root.

Plants and animals were domesticated and civilization began only ten or twelve thousand years ago. The Ionian experiment is 2,500 years old. It was almost entirely expunged. We can see steps towards science in ancient China, India and elsewhere, even though faltering, incomplete, and bearing less fruit. But suppose the lonians had never existed, and Greek science and mathematics never flourished. Is it possible that never again in the history of the human species would science have emerged? Or, given many cultures and many alternative historical skeins, isn't it likely that the right combination of factors would come into play somewhere else, sooner or later - in the islands of Indonesia, say, or in the Caribbean on the outskirts of a Mesoamerican civilization untouched by Conquistadores, or in Norse colonies on the sh.o.r.es of the Black Sea?

The impediment to scientific thinking is not, I think, the difficulty of the subject. Complex intellectual feats have been mainstays even of oppressed cultures. Shamans, magicians and theologians are highly skilled in their intricate and arcane arts. No, the impediment is political and hierarchical. In those cultures lacking unfamiliar challenges, external or internal, where fundamental change is unneeded, novel ideas need not be encouraged. Indeed, heresies can be declared dangerous; thinking can be rigidified; and sanctions against impermissible ideas can be enforced - all without much harm. But under varied and changing environmental or biological or political circ.u.mstances, simply copying the old ways no longer works. Then, a premium awaits those who, instead of blandly following tradition, or trying to foist their preferences on to the physical or social Universe, are open to what the Universe teaches. Each society must decide where in the continuum between openness and rigidity safety lies.

Greek mathematics was a brilliant step forward. Greek science, on the other hand - its first steps rudimentary and often uninformed by experiment - was riddled with error. Despite the fact that we cannot see in pitch darkness, they believed that vision depends on a kind of radar that emanates from the eye, bounces off what we're seeing, and returns to the eye. (Nevertheless, they made substantial progress in optics.) Despite the obvious resemblance of children to their mothers, they believed that heredity was carried by s.e.m.e.n alone, the woman a mere pa.s.sive receptacle. They believed that the horizontal motion of a thrown rock somehow lifts it up, so that it takes longer to reach the ground than a rock dropped from the same height at the same moment. Enamoured of simple geometry, they believed the circle to be 'perfect'; despite the 'Man in the Moon' and sunspots (occasionally visible to the naked eye at sunset), they held the heavens also to be 'perfect'; therefore, planetary orbits had to be circular.

Being freed from superst.i.tion isn't enough for science to grow. One must also have the idea of interrogating Nature, of doing experiments. There were some brilliant examples -Eratosthenes's measurement of the Earth's diameter, say, or Empedocles's clepsydra experiment demonstrating the material nature of air. But in a society in which manual labour is demeaned and thought fit only for slaves, as in the cla.s.sical Graeco-Roman world, the experimental method does not thrive. Science requires us to be freed of gross superst.i.tion and gross injustice both. Often, superst.i.tion and injustice are imposed by the same ecclesiastical and secular authorities, working hand in glove. It is no surprise that political revolutions, scepticism about religion, and the rise of science might go together. Liberation from superst.i.tion is a necessary but not a sufficient condition for science.

At the same time, it is undeniable that central figures in the transition from medieval superst.i.tion to modern science were profoundly influenced by the idea of one Supreme G.o.d who created the Universe and established not only commandments that humans must live by, but laws that Nature itself must abide by. The seventeenth-century German astronomer Johannes Kepler, without whom Newtonian physics might not have come to be, described his pursuit of science as a wish to know the mind of G.o.d. In our own time, leading scientists, including Albert Einstein and Stephen Hawking, have described their quest in nearly identical terms. The philosopher Alfred North Whitehead and the historian of Chinese technology Joseph Needham have also suggested that what was lacking in the development of science in non-western cultures was monotheism.

And yet, I think there is strong contrary evidence to this whole thesis, calling out to us from across the millennia...

The small hunting party follows the trail of hoofprints and other spoor. They pause for a moment by a stand of trees. Squatting on their heels, they examine the evidence more carefully. The trail they've been following has been crossed by another. Quickly they agree on which animals are responsible, how many of them, what ages and s.e.xes, whether any are injured, how fast they're travelling, how long ago they pa.s.sed, whether any other hunters are in pursuit, whether the party can overtake the game, and if so, how long it will take. The decision made, they flick their hands over the trail they will follow, make a quiet sound between their teeth like the wind, and off they lope. Despite their bows and poison arrows, they continue at championship marathon racing form for hours. Almost always they've read the message in the ground correctly. The wildebeests or elands or okapis are where they thought, in the numbers and condition they estimated. The hunt is successful. Meat is carried back to the temporary camp. Everyone feasts.

This more or less typical hunting vignette comes from the IKung San people of the Kalahari Desert, in the Republics of Botswana and Namibia, who are now, tragically, on the verge of extinction. But for decades they and their way of life were studied by anthropologists. The IKung San may be typical of the hunter-gatherer mode of existence in which we humans spent most of our time, until ten thousand years ago, when plants and animals were domesticated and the human condition began to change, perhaps forever. They were trackers of such legendary prowess that they were enlisted by the apartheid South African army to hunt down human prey in the wars against the 'front-line states'. This encounter with the white South African military in several different ways accelerated the destruction of the IKung San way of life. It had, in any case, been deteriorating bit by bit over the centuries from every contact with European civilization.

How did they do it? How could they tell so much from barely more than a glance? Saying they're keen observers explains nothing. What actually did they do? According to anthropologist Richard Lee: They scrutinized the shape of the depressions. The footprints of a fast-moving animal display a more elongated symmetry. A slightly lame animal favours the afflicted foot, puts less weight on it, and leaves a fainter imprint. A heavier animal leaves a deeper and broader hollow. The correlation functions are in the heads of the hunters.

In the course of the day, the footprints erode a little. The walls of the depression tend to crumble. Windblown sand acc.u.mulates on the floor of the hollow. Perhaps bits of leaf, twigs or gra.s.s are blown into it. The longer you wait, the more erosion there is.

This method is essentially identical to what planetary astronomers use in a.n.a.lysing craters left by impacting worldlets: other things being equal, the shallower the crater, the older it is. Craters with slumped walls, with modest depth-to-diameter ratios, with fine particles acc.u.mulated in their interiors tend to be more ancient, because they had to be around long enough for these erosive processes to come into play.