How should scientists respond to the allegation that our 'faith' in logic
and scientific truth is just that - faith - not 'privileged' (favourite in-
word) over alternative truths?
and scientific truth is just that - faith - not 'privileged' (favourite in-
word) over alternative truths?
Richard-Dawkins-The-Devil-s-Chaplain
' are soon dispatched: we give rights, but not the vote, to children, lunatics and Members of the House of Lords.
The biggest objection to the GAP is 'Where will it all end?
Rights for oysters?
' (Bertrand Russell's quip, in a similar context).
Where do you draw the line?
Gaps in the Mind (1.
3), my own contribution to the GAP book, uses an evolutionary argument to show that we should not be in the business of drawing lines in the first place.
There's no law of nature that says boundaries have to be clear-cut.
5
? SCIENCE AND SENSIBILITY
In December 2000 I was among those invited by David Miliband MP, then Head of the Prime Minister's Policy Unit and now Minister for School Standards, to write a memo on a particular subject for Tony Blair to read over the Christmas holiday. My brief was Science, Genetics, Risk and Ethics (1. 4) and I reproduce my (previously unpublished) contribution here (eliminating Risk and some other passages to avoid overlap with other essays).
Any proposal to curtail, in the smallest degree, the right of trial by jury is greeted with wails of affront. On the three occasions when I have been called to serve on a jury, the experience proved disagreeable and dis- illusioning. Much later, two grotesquely over-publicized trials in the United States prompted me to think through a central reason for my distrust of the jury system, and to write it down as Trial By Jury (1. 5).
Crystals are first out of the box of tricks toted by psychics, mystics, mediums and other charlatans. My purpose in the next article was to explain the real magic of crystals to the readers of a London newspaper, the Sunday Telegraph. At one time it was only the low-grade tabloid newspapers that encouraged popular superstitions like crystal-gazing or astrology. Nowadays some up-market newspapers, including the Telegraph, have dumbed down to the extent of printing a regular astrology column, which is why I accepted their invitation to write Crystalline Truth and Crystal Balls (1. 6).
A more intellectual species of charlatan is the target of the next essay, Postmodernism Disrobed (1. 7). Dawkins' Law of the Conservation of Difficulty states that obscurantism in an academic subject expands to fill the vacuum of its intrinsic simplicity. Physics is a genuinely difficult and profound subject, so physicists need to - and do - work hard to make their language as simple as possible ('but no simpler,' rightly insisted Einstein). Other academics - some would point the finger at continental schools of literary criticism and social science - suffer from what Peter Medawar (I think) called Physics Envy. They want to be thought profound, but their subject is actually rather easy and shallow, so they have to language it up to redress the balance. The physicist Alan Sokal perpetrated a blissfully funny hoax on the Editorial 'Collective' (what else? ) of a particularly pretentious journal of social studies. Afterwards, together with his colleague Jean Bricmont, he published a book, Intellectual Impostures, ably documenting this epidemic of Fashionable Nonsense (as their book was retitled in the United States). 'Postmodernism Disrobed' is my review of this hilarious but disquieting book.
I must add, the fact that the word 'postmodernism' occurs in the title given me by the Editors of Nature does not imply that I (or they) know what it means. Indeed, it is my belief that it means nothing at all, except in the
6
? restricted context of architecture where it originated. I recommend the following practice, whenever anybody uses the word in some other context. Stop them instantly and ask, in a neutral spirit of friendly curiosity, what it means. Never once have I heard anything that even remotely approaches a usable, or even faintly coherent, definition. The best you'll get is a nervous titter and something like, 'Yes I agree, it is a terrible word isn't it, but you know what I mean. ' Well no, actually, I don't.
As a lifelong teacher, I fret about where we go wrong in education. I hear horror stories almost daily of ambitious parents or ambitious schools ruining the joy of childhood. And it starts wretchedly early. A six-year-old boy receives 'counselling' because he is 'worried' that his performance in mathematics is falling behind. A headmistress summons the parents of a little girl to suggest that she should be sent for external tuition. The parents expostulate that it is the school's job to teach the child. Why is she falling behind? She is falling behind, explains the headmistress patiently, because the parents of all the other children in the class are paying for them to go to external tutors.
It is not just the joy of childhood that is threatened. It is the joy of true education: of reading for the sake of a wonderful book rather than for an exam; of following up a subject because it is fascinating rather than because it is on a syllabus; of watching a great teacher's eyes light up for sheer love of the subject. The Joy of Living Dangerously: Sanderson of Oundle (1. 8) is an attempt to bring back from the past the spirit of just such a great teacher.
SCIENCE AND SENSIBILITY
7
? 8 %: I
A Devil's Chaplain
Darwin was less than half joking when he coined the phrase Devil's Chaplain in a letter to his friend Hooker in 1856.
What a book a Devil's Chaplain might write on the clumsy, wasteful, blundering low and horridly cruel works of nature.
A process of trial and error, completely unplanned and on the massive scale of natural selection, can be expected to be clumsy, wasteful and blundering. Of waste there is no doubt. As I have put it before, the racing elegance of cheetahs and gazelles is bought at huge cost in blood and the suffering of countless antecedents on both sides. Clumsy and blundering though the process undoubtedly is, its results are opposite. There is nothing clumsy about a swallow; nothing blundering about a shark. What is clumsy and blundering, by the standards of human drawing boards, is the Darwinian algorithm that led to their evolution. As for cruelty, here is Darwin again, in a letter to Asa Gray of 1860:
I cannot persuade myself that a beneficent and omnipotent God would have designedly created the Ichneumonidae with the express intention of their feeding within the living bodies of Caterpillars.
Darwin's French contemporary Jean Henri Fabre described similar behaviour in a digger wasp, Ammophila:
It is the general rule that larvae possess a centre of innervation for each segment.
This is so in particular with the Grey Worm, the sacrificial victim of the Hairy
Ammophila. The Wasp is acquainted with this anatomical secret: she stabs the
caterpillar again and again, from end to end, segment by segment, ganglion by
1 ganglion.
Darwin's Ichneumonidae, like Fabre's digger wasps, sting their prey not to kill but to paralyse, so their larvae can feed on fresh (live) meat. As
8
? Darwin clearly understood, blindness to suffering is an inherent con- sequence of natural selection, although on other occasions he tried to play down the cruelty, suggesting that killing bites are mercifully swift. But the Devil's Chaplain would be equally swift to point out that if there is mercy in nature, it is accidental. Nature is neither kind nor cruel but indifferent. Such kindness as may appear emerges from the same imperative as the cruelty. In the words of one of Darwin's most
2 thoughtful successors, George C. Williams ,
With what other than condemnation is a person with any moral sense supposed to respond to a system in which the ultimate purpose in life is to be better than your neighbor at getting genes into future generations, in which those success- ful genes provide the message that instructs the development of the next generation, in which that message is always 'exploit your environment, includ- ing your friends and relatives, so as to maximize our genes' success', in which the closest thing to a golden rule is 'don't cheat, unless it is likely to provide a net benefit'?
Bernard Shaw was driven to embrace a confused idea of Lamarckian evolution purely because of Darwinism's moral implications. He wrote, in the Preface to Back to Methuselah:
When its whole significance dawns on you, your heart sinks into a heap of sand within you. There is a hideous fatalism about it, a ghastly and damnable reduction of beauty and intelligence, of strength and purpose, of honor and aspiration.
His Devil's Disciple was an altogether jollier rogue than Darwin's
Chaplain. Shaw didn't think of himself as religious, but he had that
childlike inability to distinguish what is true from what we'd like to be
true. The same kind of thing drives today's populist opposition to
3 evolution :
The most evolution could produce would be the idea that 'might makes right. ' When Hitler exterminated approximately 10 million innocent men, women, and children, he acted in complete agreement with the theory of evolution and in complete disagreement with everything humans know to be right and wrong . . . If you teach children that they evolved from monkeys, then they will act like monkeys.
An opposite response to the callousness of natural selection is to exult
in it, along with the Social Darwinists and - astonishingly - H. G. Wells.
The New Republic, where Wells outlines his Darwinian Utopia, contains
4 some blood-chilling lines:
A DEVIL'S CHAPLAIN
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? SCIENCE AND SENSIBILITY
And how will the New Republic treat the inferior races? How will it deal with the black? . . . the yellow man? . . . the Jew? . . . those swarms of black, and brown, and dirty-white, and yellow people, who do not come into the new needs of efficiency? Well, the world is a world, and not a charitable institution, and I take it they will have to go . . . And the ethical system of these men of the New Republic, the ethical system which will dominate the world state, will be shaped primarily to favour the procreation of what is fine and efficient and beautiful in humanity - beautiful and strong bodies, clear and powerful minds . . . And the method that nature has followed hitherto in the shaping of the world, whereby weakness was prevented from propagating weakness . . . is death . . . The men of the New Republic . . . will have an ideal that will make the killing worth the while.
Wells's colleague Julian Huxley downplayed, in effect, the pessimism of
the Devil's Chaplain as he tried to build an ethical system on what he
saw as evolution's progressive aspects. His 'Progress, Biological and
5
Other', the first of his Essays of a Biologist, almost like a call to arms under evolution's banner:
[man's] face is set in the same direction as the main tide of evolving life, and his highest destiny, the end towards which he has so long perceived that he must strive, is to extend to new possibilities the process with which, for all these millions of years, nature has already been busy, to introduce less and less wasteful methods, to accelerate by means of his consciousness what in the past has been the work of blind unconscious forces.
I prefer to stand up with Julian's refreshingly belligerent grandfather T. H. Huxley, agree that natural selection is the dominant force in bio- logical evolution unlike Shaw, admit its unpleasantness unlike Julian, and, unlike Wells, fight against it as a human being. Here is T. H. , in his
6 Romanes Lecture. in Oxford in 1893, on 'Evolution and Ethics':
Let us understand, once for all, that the ethical progress of society depends, not on imitating the cosmic process, still less in running away from it, but in combating it.
That is G. C. Williams's recommendation today, and it is mine. I hear the bleak sermon of the Devil's Chaplain as a call to arms. As an academic scientist I am a passionate Darwinian, believing that natural selection is, if not the only driving force in evolution, certainly the only known force capable of producing the illusion of purpose which so strikes all who contemplate nature. But at the same time as I support Darwinism as a scientist, I am a passionate anti-Darwinian when it
10
contains passages that read
? comes to politics and how we should conduct our human affairs. My previous books, such as The Selfish Gene and The Blind Watchmaker, extol the inescapable factual correctness of the Devil's Chaplain (had Darwin decided to extend the list of melancholy adjectives in the Chaplain's indictment, he would very probably have chosen both 'selfish' and 'blind'). At the same time I have always held true to the closing words of my first book, 'We, alone on earth, can rebel against the tyranny of the selfish replicators. '
If you seem to smell inconsistency or even contradiction, you are mistaken. There is no inconsistency in favouring Darwinism as an academic scientist while opposing it as a human being; any more than there is inconsistency in explaining cancer as an academic doctor while fighting it as a practising one. For good Darwinian reasons, evolution gave us a brain whose size increased to the point where it became capable of understanding its own provenance, of deploring the moral implications and of fighting against them. Every time we use contra- ception we demonstrate that brains can thwart Darwinian designs. If, as my wife suggests to me, selfish genes are Frankensteins and all life their monster, it is only we that can complete the fable by turning against our creators. We face an almost exact negation of Bishop Heber's lines, 'Though every prospect pleases, And only man is vile. ' Yes, man can be vile too, but we are the only potential island of refuge from the implications of the Devil's Chaplain: from the cruelty, and the clumsy, blundering waste.
For our species, with its unique gift of foresight - product of the simulated virtual-reality we call the human imagination - can plan the very opposite of waste with, if we get it right, a minimum of clumsy blunders. And there is true solace in the blessed gift of understanding, even if what we understand is the unwelcome message of the Devil's Chaplain. It is as though the Chaplain matured and offered a second half to the sermon. Yes, says the matured Chaplain, the historic process that caused you to exist is, wasteful, cruel and low. But exult in your existence, because that very process has blundered unwittingly on its own negation. Only a small, local negation, to be sure: only one species, and only a minority of the members of that species; but there lies hope.
Exult even more that the clumsy and cruel algorithm of natural
selection has generated a machine capable of internalizing the
algorithm, setting up a model of itself - and much more - in microcosm
inside the human skull. I may have disparaged Julian Huxley in these
pages, but he published a poem in 1926 which says something of what
8
I want to say (and a few things that I don't want to say):
7
A DEVIL'S CHAPLAIN
11
? SCIENCE AND SENSIBILITY
The world of things entered your infant mind
To populate that crystal cabinet.
Within its walls the strangest partners met,
And things turned thoughts did propagate their kind. For, once within, corporeal fact could find
A spirit. Fact and you in mutual debt
Built there your little microcosm - which yet Had hugest tasks to its small self assigned.
Dead men can live there, and converse with stars: Equator speaks with pole, and night with day: Spirit dissolves the world's material bars -
A million isolations burn away.
The Universe can live and work and plan, At last made God within the mind of man.
9
This earth is one of the rare spots in the cosmos where mind has flowered. Man is a product of nearly three billion years of evolution, in whose person the evolutionary process has at last become conscious of itself and its possibilities. Whether he likes it or not, he is responsible for the whole further evolution of our planet.
Huxley's fellow luminary of the neo-Darwinian synthesis, the great
Russian-American geneticist Theodosius Dobzhansky said something
10 similar:
In giving rise to man, the evolutionary process has, apparently for the first and only time in the history of the Cosmos, become conscious of itself.
So, the Devil's Chaplain might conclude, Stand tall, Bipedal Ape. The shark may outswim you, the cheetah outrun you, the swift outfly you, the capuchin outclimb you, the elephant outpower you, the redwood outlast you. But you have the biggest gifts of all: the gift of under- standing the ruthlessly cruel process that gave us all existence; the gift of revulsion against its implications; the gift of foresight - something utterly foreign to the blundering short-term ways of natural selection - and the gift of internalizing the very cosmos.
We are blessed with brains which, if educated and allowed free rein, are capable of modelling the universe, with its physical laws in which the Darwinian algorithm is embedded. As Darwin himself put it, in the famous closing lines of the Origin of Species:
Julian Huxley later wrote, in his Essays of a Humanist:
12
? Thus, from the war of nature, from famine and death, the most exalted object which we are capable of conceiving, namely, the production of the higher animals, directly follows. There is grandeur in this view of life, with its several powers, having been originally breathed* into a few forms or into one; and that, whilst this planet has gone cycling on according to the fixed law of gravity, from so simple a beginning endless forms most beautiful and most wonderful have been, and are being, evolved.
There is more than just grandeur in this view of life, bleak and cold though it can seem from under the security blanket of ignorance. There is deep refreshment to be had from standing up full-face into the keen wind of understanding: Yeats's 'Winds that blow through the starry ways'. In another essay, I quote the words of an inspiring teacher, F. W. Sanderson, who urged his pupils to 'live dangerously . . . '
. . . full of the burning fire of enthusiasm, anarchic, revolutionary, energetic, daemonic, Dionysian, filled to overflowing with the terrific urge to create - such is the life of the man who risks safety and happiness for the sake of growth and happiness.
Safety and happiness would mean being satisfied with easy answers and cheap comforts, living a warm comfortable lie. The daemonic alterna- tive urged by my matured Devil's Chaplain is risky. You stand to lose comforting delusions: you can no longer suck at the pacifier of faith in immortality. To set against that risk, you stand to gain 'growth and happiness'; the joy of knowing that you have grown up, faced up to what existence means; to the fact that it is temporary and all the more precious for it. y
*In the Second Edition, and all subsequent editions of the Origin, the three words 'by the Creator' were interpolated at this point, presumably as a sop to religious sensibilities.
fNote added in proof: I was unaware, when I chose this title, that the BBC had used Darwin's phrase, 'Devil's Chaplain', for an excellent documentary based on Adrian Desmond and James Moore's biography.
A DEVIL'S CHAPLAIN
13
? "1 sJiJ
What is True? 11
A little learning is a dangerous thing. This has never struck me as a particularly profound or wise remark,* but it comes into its own in the special case where the little learning is in philosophy (as it often is). A scientist who has the temerity to utter the t-word ('true') is likely to encounter a form of philosophical heckling which goes something like this:
There is no absolute truth. You are committing an act of personal faith when you claim that the scientific method, including mathematics and logic, is the privileged road to truth. Other cultures might believe that truth is to be found in a rabbit's entrails, or the ravings of a prophet up a pole. It is only your personal faith in science that leads you to favour your brand of truth.
That strand of half-baked philosophy goes by the name of cultural
relativism. It is one aspect of the Fashionable Nonsense detected by Alan 12
Sokal and Jean Bricmont, or the Higher Superstition of Paul Gross and 13
Norman Levitt. The feminist version is ably exposed by Daphne Patai
and Noretta Koertge, authors of Professing Feminism: Cautionary Tales
1 from the Strange World of Women's Studies: '
Women's Studies students are now being taught that logic is a tool of domination . . . the standard norms and methods of scientific inquiry are sexist because they are incompatible with 'women's ways of knowing'. . . These 'subjectivist' women see the methods of logic, analysis and abstraction as 'alien territory belonging to men' and 'value intuition as a safer and more fruitful approach to truth'.
How should scientists respond to the allegation that our 'faith' in logic
and scientific truth is just that - faith - not 'privileged' (favourite in-
word) over alternative truths? A minimal response is that science gets
ls results. As I put it in River Out ofEden,
*Pope's original is wonderful, but the aphorism doesn't survive isolation from its context. 14
? Show me a cultural relativist at 30,000 feet and I'll show you a hypocrite . . . If you are flying to an international congress of anthropologists or literary critics, the reason you will probably get there - the reason you don't plummet into a ploughed field - is that a lot of Western scientifically trained engineers have got their sums right.
Science boosts its claim to truth by its spectacular ability to make matter and energy jump through hoops on command, and to predict what will happen and when.
But is it still just our Western scientific bias to be impressed by accurate prediction; impressed by the power to slingshot rockets around Jupiter to reach Saturn, or intercept and repair the Hubble telescope; impressed by logic itself? Well, let's concede the point and think sociologically, even democratically. Suppose we agree, temporarily, to treat scientific truth as just one truth among many, and lay it alongside all the rival contenders: Trobriand truth, Kikuyu truth, Maori truth, Inuit truth, Navajo truth, Yanomamo truth, IKung San truth, feminist truth, Islamic truth, Hindu truth. The list is endless - and thereby hangs
a revealing observation.
In theory, people could switch allegiance from any one 'truth' to any
other if they decide it has greater merit. On what basis might they do so? Why would one change from, say, Kikuyu truth to Navajo truth? Such merit-driven switches are rare. With one crucially important excep- tion. Scientific truth is the only member of the list which regularly persuades converts of its superiority. People are loyal to other belief systems for one reason only: they were brought up that way, and they have never known anything better. When people are lucky enough to be offered the opportunity to vote with their feet, doctors and their kind prosper while witch doctors decline. Even those who do not, or cannot, avail themselves of a scientific education, choose to benefit from the technology that is made possible by the scientific education of others. Admittedly, religious missionaries have successfully claimed converts in great numbers all over the underdeveloped world. But they succeed not because of the merits of their religion but because of the science-based technology for which it is pardonably, but wrongly, given credit.
Surely the Christian God must be superior to our Juju, because Christ's representatives come bearing rifles, telescopes, chainsaws, radios, almanacs that predict eclipses to the minute, and medicines that work.
WHAT IS TRUE?
15
? SCIENCE AND SENSIBILITY
So much for cultural relativism. A different type of truth-heckler prefers to drop the name of Karl Popper or (more fashionably) Thomas Kuhn:
There is no absolute truth. Your scientific truths are merely hypotheses that have so far failed to be falsified, destined to be superseded. At worst, after the next scientific revolution, today's 'truths' will seem quaint and absurd, if not actually false. The best you scientists can hope for is a series of approximations which progressively reduce errors but never eliminate them.
The Popperian heckle partly stems from the accidental fact that philosophers of science are traditionally obsessed with one piece of scientific history: the comparison between Newton's and Einstein's theories of gravitation. It is true that Newton's inverse square law has turned out to be an approximation, a special case of Einstein's more general formula. If this is the only piece of scientific history you know, you might indeed conclude that all apparent truths are mere approxi- mations, fated to be superseded. There is even a quite interesting sense in which all our sensory perceptions - the 'real' things that we 'see with our own eyes' - may be regarded as unfalsified 'hypotheses' about the world, vulnerable to change. This provides a good way to think about illusions such as the Necker Cube.
The flat pattern of ink on paper is compatible with two alternative 'hypotheses' of solidity. So we see a solid cube which, after a few seconds, 'flips' to a different cube, then flips back to the first cube, and so on. Perhaps sense data only ever confirm or reject mental 'hypotheses'
16 about what is out there.
Well, that is an interesting theory; so is the philosopher's notion that science proceeds by conjecture and refutation; and so is the analogy between the two. This line of thought - all our percepts are hypo- thetical models in the brain - might lead us to fear some future blurring of the distinction between reality and illusion in our descendants, whose lives will be even more dominated by computers capable of
16
? generating vivid models of their own. Without venturing into the high- tech worlds of virtual reality, we already know that our senses are easily deceived. Conjurors - professional illusionists - can persuade us, if we lack a sceptical foothold in reality, that something supernatural is going on. Indeed, some notorious erstwhile conjurors make a fat living doing exactly that: a living much fatter than they ever enjoyed when they frankly admitted that they were conjurors. * Scientists, alas, are not best equipped to unmask telepathists, mediums and spoon-bending charlatans. This is a job which is best handed over to the professionals, and that means other conjurors. The lesson that conjurors, the honest variety and the impostors, teach us is that an uncritical faith in our own senses is not an infallible guide to truth.
But none of this seems to undermine our ordinary concept of what it means for something to be true. If I am in the witness box, and prosecuting counsel wags his stern finger and demands, 'Is it or is it not true that you were in Chicago on the night of the murder? ', I should get pretty short shrift if I said,
What do you mean by true? The hypothesis that I was in Chicago has not so far been falsified, but it is only a matter of time before we see that it is a mere approximation.
Or, reverting to the first heckle, I would not expect a jury, even a Bongolese jury, to give a sympathetic hearing to my plea that,
It is only in your western scientific sense of the word 'in' that I was in Chicago. The Bongolese have a completely different concept of 'in', according to which you are only truly 'in' a place if you are an anointed elder entitled to take snuff from the dried scrotum of a goat.
It is simply true that the Sun is hotter than the Earth, true that the desk on which I am writing is made of wood. These are not hypotheses awaiting falsification; not temporary approximations to an ever-elusive truth; not local truths that might be denied in another culture. And the same can safely be said of many scientific truths, even where we can't see them 'with our own eyes'. It is forever true that DNA is a double helix, true that if you and a chimpanzee (or an octopus or a kangaroo)
'Performing psychics and mystics, who happily perform in front of scientists, will con- veniently plead a headache and refuse to go on if informed that a contingent of professional conjurors is in the front row of the stalls. It is for the same reason that the then Editor of Nature, John Maddox, took James 'The Amazing' Randi with him when investigating a suspected case of homeopathic fraud. This caused some resentment at the time, but it was an entirely reasonable decision. Any genuine scientist has nothing to fear from a sceptical conjuror looking over his shoulder.
WHAT IS TRUE?
17
? SCIENCE AND SENSIBILITY
trace your ancestors back far enough you will eventually hit a shared ancestor. To a pedant, these are still hypotheses which might be falsified tomorrow. But they never will be. Strictly, the truth that there were no human beings in the Jurassic Period is still a conjecture, which could be refuted at any time by the discovery of a single fossil, authentically dated by a battery of radiometric methods. It could happen. Want a bet? Even if they are nominally hypotheses on probation, these statements are true in exactly the same sense as the ordinary truths of everyday life; true in the same sense as it is true that you have a head, and that my desk is wooden. If scientific truth is open to philosophic doubt, it is no more so than common sense truth. Let's at least be even-handed in our philosophical heckling.
A more profound difficulty now arises for our scientific concept of truth. Science is very much not synonymous with common sense. Admittedly, that doughty scientific hero T. H. Huxley said:
Science is nothing but trained and organized common sense, differing from the latter only as a veteran may differ from a raw recruit: and its methods differ from those of common sense only as far as the guardsman's cut and thrust differ from the manner in which a savage wields his club.
But Huxley was talking about the methods of science, not its conclusions. As Lewis Wolpert emphasized in The Unnatural Nature of
17
Science, the conclusions can be disturbingly counter-intuitive.
Quantum theory is counter-intuitive to the point where the physicist sometimes seems to be battling insanity. We are asked to believe that a single quantum behaves like a particle in going through one hole instead of another, but simultaneously behaves like a wave in interfer- ing with a non-existent copy of itself, if another hole is opened through which that non-existent copy could have travelled (if it had existed). It gets worse, to the point where some physicists resort to a vast number of parallel but mutually unreachable worlds, which proliferate to accommodate every alternative quantum event; while other physicists, equally desperate, suggest that quantum events are determined retro- spectively by our decision to examine their consequences. Quantum theory strikes us as so weird, so defiant of common sense, that even the great Richard Feynman was moved to remark, T think I can safely say that nobody understands quantum mechanics. ' Yet the many predic- tions by which quantum theory has been tested stand up, with an accuracy so stupendous that Feynman compared it to measuring the distance between New York and Los Angeles accurately to the width of one human hair. On the basis of these stunningly successful
18
? predictions, quantum theory, or some version of it, seems to be as true as anything we know.
Modern physics teaches us that there is more to truth than meets the eye; or than meets the all too limited human mind, evolved as it was to cope with medium-sized objects moving at medium speeds through medium distances in Africa. In the face of these profound and sublime mysteries, the low-grade intellectual poodling of pseudo-philosophical poseurs seems unworthy of adult attention.
WHAT IS TRUE?
19
? Gaps in the Mind
Sir,
You appeal for money to save the gorillas. Very laudable, no doubt. But it doesn't seem to have occurred to you that there are thousands of human children suffering on the very same continent of Africa. There'll be time enough to worry about gorillas when we've taken care of every last one of the kiddies. Let's get our priorities right, p/ease!
This hypothetical letter could have been written by almost any well- meaning person today. In lampooning it, I don't mean to imply that a good case could not be made for giving human children priority. I expect
it could, and also that a good case could be made the other way. I'm only trying to point the finger at the automatic, unthinking nature of the speciesist double standard. To many people it is simply self-evident, without any discussion, that humans are entitled to special treatment. To see this, consider the following variant on the same letter:
Sir,
You appeal for money to save the gorillas. Very laudable, no doubt. But it doesn't seem to have occurred to you that there are thousands of aardvarks suffering on the very same continent of Africa. There'll be time enough to worry about gorillas when we've saved every last one of the aardvarks. Let's get our priorities right, p/ease!
This second letter could not fail to provoke the question: What's so special about aardvarks? A good question, and one to which we should require a satisfactory answer before we took the letter seriously. Yet the first letter, I suggest, would not for most people provoke the equivalent question, 'What's so special about humans? ' As I said, I don't deny that this question, unlike the aardvark question, very probably has a power- ful answer. All that I am criticizing is an unthinking failure to realize in the case of humans that the question even arises.
20
? The speciesist* assumption that lurks here is very simple. Humans are humans and gorillas are animals. There is an unquestioned yawning gulf between them such that the life of a single human child is worth more than the lives of all the gorillas in the world. The 'worth' of an animal's life is just its replacement cost to its owner - or, in the case of
a rare species, to humanity. But tie the label Homo sapiens even to a tiny piece of insensible, embryonic tissue, and its life suddenly leaps to infinite, uncomputable value.
This way of thinking characterizes what I want to call the discontinuous mind. We'd all agree that a six-foot woman is tall, and a five-foot woman is not. Words like 'tall' and 'short' tempt us to force the world into qualitative classes, but this doesn't mean that the world really is discontinuously distributed. Were you to tell me that a woman is five feet nine inches tall, and ask me to decide whether she should therefore be called tall or not, I'd shrug and say, 'She's five foot nine, doesn't that tell you what you need to know? ' But the discontinuous mind, to caricature it a little, would go to court to decide (probably at great expense) whether the woman was tall or short. Indeed, I hardly need to say caricature. For years, South African courts have done a brisk trade adjudicating whether particular individuals of mixed parentage count as white, black or 'coloured'. t
The discontinuous mind is ubiquitous. It is especially influential when it afflicts lawyers and the religious (not only are all judges lawyers; a high proportion of politicians are too, and all politicians have to woo the religious vote). Recently, after giving a public lecture, I was cross-examined by a lawyer in the audience. He brought the full weight of his legal acumen to bear on a nice point of evolution. If species A evolves into a later species B, he reasoned closely, there must come a point when a mother belongs to the old species A and her child belongs to the new species B. Members of different species cannot interbreed with one another. I put it to you, he went on, that a child could hardly be so different from its parents that it could not interbreed with their kind. So, he wound up triumphantly, isn't this a fatal flaw in the theory of evolution?
But it is we that choose to divide animals up into discontinuous species. On the evolutionary view of life there must have been inter- mediates, even though, conveniently for our naming rituals, they are today usually extinct. They are not always extinct. The lawyer would be
'Coined by Richard Ryder and given currency by Peter Singer, the analogy is to racism. tThankfully no longer. The apartheid regime is one of history's monuments to the tyranny of the discontinuous mind.
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surprised and, I hope, intrigued by so-called 'ring species'. The best- known case is the Herring Gull/Lesser Black-backed Gull ring. In Britain these are clearly distinct species, quite different in colour. Anybody can tell them apart. But if you follow the population of Herring Gulls westward round the North Pole to North America, then via Alaska across Siberia and back to Europe again, you notice a curious fact. The 'Herring Gulls' gradually become less and less like Herring Gulls and more and more like Lesser Black-backed Gulls until it turns out that our European Lesser Black-backed Gulls actually are the other end of a ring that started out as Herring Gulls. At every stage around the ring, the birds are sufficiently similar to their neighbours to interbreed with them. Until, that is, the ends of the continuum are reached, in Europe. At this point the Herring Gull and the Lesser Black-backed Gull never interbreed, although they are linked by a continuous series of interbreeding colleagues all the way round the world. The only thing that is special about ring species like these gulls is that the intermediates are still alive. All pairs of related species are potentially ring species. The intermediates must have lived once. It is just that in most cases they are now dead.
The lawyer, with his trained discontinuous mind, insists on placing individuals firmly in this species or that. He does not allow for the possibility that an individual might lie halfway between two species, or a tenth of the way from species A to species B. Self-styled 'pro-lifers', and others that indulge in footling debates about exactly when in its development a foetus 'becomes human', exhibit the same discon- tinuous mentality. It is no use telling these people that, depending upon the human characteristics that interest you, a foetus can be 'half human' or 'a hundredth human'. 'Human', to the discontinuous mind, is an absolutist concept. There can be no half measures. And from this flows much evil.
The word 'apes' usually means chimpanzees, gorillas, orang utans, gibbons and siamangs. We admit that we are like apes, but we seldom realize that we are apes. Our common ancestor with the chimpanzees and gorillas is much more recent than their common ancestor with the Asian apes - the gibbons and orang utans. There is no natural category that includes chimpanzees, gorillas and orangs but excludes humans. The artificiality of the category 'apes', as conventionally taken to exclude humans, is demonstrated by the following diagram. The family tree shows humans to be in the thick of the ape cluster; the artificiality of the conventional category 'ape' is shown by the stippling.
22
? Gibbon
Siamang
Gorilla
Pigmy Chimpanzee Chimpanzee Human
I Orang Utan
- 'APES'
In truth, not only are we apes, we are African apes. The category 'African apes', if you don't arbitrarily exclude humans, is a natural category. The stippled area doesn't have any artificial 'bites' taken out of it:
Gibbon
Siamang
Gorilla
Pigmy Chimpanzee Chimpanzee Human
i Orang Utan
- AFRICAN APES
All the African apes that have ever lived, including ourselves, are linked to one another by an unbroken chain of parent-child bonds. The same is true of all animals and plants that have ever lived, but there the distances involved are much greater. Molecular evidence suggests that our common ancestor with chimpanzees lived, in Africa, between 5 and 7 million years ago, say half a million generations ago. This is not long by evolutionary standards.
Happenings are sometimes organized at which thousands of people hold hands and form a human chain, say from coast to coast of the United States, in aid of some cause or charity. Let us imagine setting one up along the equator, across the width of our home continent of Africa. It is a special kind of chain, involving parents and children, and we'll have to play tricks with time in order to imagine it. You stand on the shore of the Indian Ocean in southern Somalia, facing north, and in
GAPS IN THE MIND
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your left hand you hold the right hand of your mother. In turn she holds the hand of her mother, your grandmother. Your grandmother holds her mother's hand, and so on. The chain wends its way up the beach, into the arid scrubland and westwards on towards the Kenya border.
How far do we have to go until we reach our common ancestor with the chimpanzees? It's a surprisingly short way. Allowing one yard per person, we arrive at the ancestor we share with chimpanzees in under 300 miles. We've hardly started to cross the continent; we're still not half way to the great Rift Valley. The ancestor is standing well to the east of Mount Kenya, and holding in her hand an entire chain of her lineal descendants, culminating in you standing on the Somali beach.
The daughter that she is holding in her right hand is the one from whom we are descended. Now the arch-ancestress turns eastward to face the coast, and with her left hand grasps her other daughter, the one from whom the chimpanzees are descended (or son, of course, but let's stick to females for convenience). The two sisters are facing one another, and each holding their mother by the hand. Now the second daughter, the chimpanzee ancestress, holds her daughter's hand, and a new chain is formed, proceeding back towards the coast. First cousin faces first cousin, second cousin faces second cousin, and so on. By the time the folded-back chain has reached the coast again, it consists of modern chimpanzees. You are face to face with your chimpanzee cousin, and you are joined to her by an unbroken chain of mothers holding hands with daughters. If you walked up the line like an inspecting general - past Homo erectus, Homo habilis, perhaps Australopithecus afarensis - and down again the other side (the intermediates on the chimpanzee side are unnamed because, as it happens, no fossils have been found), you would nowhere find any sharp discontinuity. Daughters would resemble mothers just as much (or as little) as they always do. Mothers would love daughters, and feel affinity with them, just as they always do. And this hand-in-hand continuum, joining us seamlessly to chimpanzees, is so short that it barely makes it past the hinterland of Africa, the mother continent.
Our chain of African apes in time, doubling back on itself, is in miniature like the ring of gulls in space, except that the intermediates happen to be dead. The point I want to make is that, as far as morality is concerned, it should be incidental that the intermediates are dead. What if they were not? What if a clutch of intermediate types had survived, enough to link us to modern chimpanzees by a chain, not just of hand-holders, but of interbreeders? Remember the song, 'I've danced
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In December 2000 I was among those invited by David Miliband MP, then Head of the Prime Minister's Policy Unit and now Minister for School Standards, to write a memo on a particular subject for Tony Blair to read over the Christmas holiday. My brief was Science, Genetics, Risk and Ethics (1. 4) and I reproduce my (previously unpublished) contribution here (eliminating Risk and some other passages to avoid overlap with other essays).
Any proposal to curtail, in the smallest degree, the right of trial by jury is greeted with wails of affront. On the three occasions when I have been called to serve on a jury, the experience proved disagreeable and dis- illusioning. Much later, two grotesquely over-publicized trials in the United States prompted me to think through a central reason for my distrust of the jury system, and to write it down as Trial By Jury (1. 5).
Crystals are first out of the box of tricks toted by psychics, mystics, mediums and other charlatans. My purpose in the next article was to explain the real magic of crystals to the readers of a London newspaper, the Sunday Telegraph. At one time it was only the low-grade tabloid newspapers that encouraged popular superstitions like crystal-gazing or astrology. Nowadays some up-market newspapers, including the Telegraph, have dumbed down to the extent of printing a regular astrology column, which is why I accepted their invitation to write Crystalline Truth and Crystal Balls (1. 6).
A more intellectual species of charlatan is the target of the next essay, Postmodernism Disrobed (1. 7). Dawkins' Law of the Conservation of Difficulty states that obscurantism in an academic subject expands to fill the vacuum of its intrinsic simplicity. Physics is a genuinely difficult and profound subject, so physicists need to - and do - work hard to make their language as simple as possible ('but no simpler,' rightly insisted Einstein). Other academics - some would point the finger at continental schools of literary criticism and social science - suffer from what Peter Medawar (I think) called Physics Envy. They want to be thought profound, but their subject is actually rather easy and shallow, so they have to language it up to redress the balance. The physicist Alan Sokal perpetrated a blissfully funny hoax on the Editorial 'Collective' (what else? ) of a particularly pretentious journal of social studies. Afterwards, together with his colleague Jean Bricmont, he published a book, Intellectual Impostures, ably documenting this epidemic of Fashionable Nonsense (as their book was retitled in the United States). 'Postmodernism Disrobed' is my review of this hilarious but disquieting book.
I must add, the fact that the word 'postmodernism' occurs in the title given me by the Editors of Nature does not imply that I (or they) know what it means. Indeed, it is my belief that it means nothing at all, except in the
6
? restricted context of architecture where it originated. I recommend the following practice, whenever anybody uses the word in some other context. Stop them instantly and ask, in a neutral spirit of friendly curiosity, what it means. Never once have I heard anything that even remotely approaches a usable, or even faintly coherent, definition. The best you'll get is a nervous titter and something like, 'Yes I agree, it is a terrible word isn't it, but you know what I mean. ' Well no, actually, I don't.
As a lifelong teacher, I fret about where we go wrong in education. I hear horror stories almost daily of ambitious parents or ambitious schools ruining the joy of childhood. And it starts wretchedly early. A six-year-old boy receives 'counselling' because he is 'worried' that his performance in mathematics is falling behind. A headmistress summons the parents of a little girl to suggest that she should be sent for external tuition. The parents expostulate that it is the school's job to teach the child. Why is she falling behind? She is falling behind, explains the headmistress patiently, because the parents of all the other children in the class are paying for them to go to external tutors.
It is not just the joy of childhood that is threatened. It is the joy of true education: of reading for the sake of a wonderful book rather than for an exam; of following up a subject because it is fascinating rather than because it is on a syllabus; of watching a great teacher's eyes light up for sheer love of the subject. The Joy of Living Dangerously: Sanderson of Oundle (1. 8) is an attempt to bring back from the past the spirit of just such a great teacher.
SCIENCE AND SENSIBILITY
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A Devil's Chaplain
Darwin was less than half joking when he coined the phrase Devil's Chaplain in a letter to his friend Hooker in 1856.
What a book a Devil's Chaplain might write on the clumsy, wasteful, blundering low and horridly cruel works of nature.
A process of trial and error, completely unplanned and on the massive scale of natural selection, can be expected to be clumsy, wasteful and blundering. Of waste there is no doubt. As I have put it before, the racing elegance of cheetahs and gazelles is bought at huge cost in blood and the suffering of countless antecedents on both sides. Clumsy and blundering though the process undoubtedly is, its results are opposite. There is nothing clumsy about a swallow; nothing blundering about a shark. What is clumsy and blundering, by the standards of human drawing boards, is the Darwinian algorithm that led to their evolution. As for cruelty, here is Darwin again, in a letter to Asa Gray of 1860:
I cannot persuade myself that a beneficent and omnipotent God would have designedly created the Ichneumonidae with the express intention of their feeding within the living bodies of Caterpillars.
Darwin's French contemporary Jean Henri Fabre described similar behaviour in a digger wasp, Ammophila:
It is the general rule that larvae possess a centre of innervation for each segment.
This is so in particular with the Grey Worm, the sacrificial victim of the Hairy
Ammophila. The Wasp is acquainted with this anatomical secret: she stabs the
caterpillar again and again, from end to end, segment by segment, ganglion by
1 ganglion.
Darwin's Ichneumonidae, like Fabre's digger wasps, sting their prey not to kill but to paralyse, so their larvae can feed on fresh (live) meat. As
8
? Darwin clearly understood, blindness to suffering is an inherent con- sequence of natural selection, although on other occasions he tried to play down the cruelty, suggesting that killing bites are mercifully swift. But the Devil's Chaplain would be equally swift to point out that if there is mercy in nature, it is accidental. Nature is neither kind nor cruel but indifferent. Such kindness as may appear emerges from the same imperative as the cruelty. In the words of one of Darwin's most
2 thoughtful successors, George C. Williams ,
With what other than condemnation is a person with any moral sense supposed to respond to a system in which the ultimate purpose in life is to be better than your neighbor at getting genes into future generations, in which those success- ful genes provide the message that instructs the development of the next generation, in which that message is always 'exploit your environment, includ- ing your friends and relatives, so as to maximize our genes' success', in which the closest thing to a golden rule is 'don't cheat, unless it is likely to provide a net benefit'?
Bernard Shaw was driven to embrace a confused idea of Lamarckian evolution purely because of Darwinism's moral implications. He wrote, in the Preface to Back to Methuselah:
When its whole significance dawns on you, your heart sinks into a heap of sand within you. There is a hideous fatalism about it, a ghastly and damnable reduction of beauty and intelligence, of strength and purpose, of honor and aspiration.
His Devil's Disciple was an altogether jollier rogue than Darwin's
Chaplain. Shaw didn't think of himself as religious, but he had that
childlike inability to distinguish what is true from what we'd like to be
true. The same kind of thing drives today's populist opposition to
3 evolution :
The most evolution could produce would be the idea that 'might makes right. ' When Hitler exterminated approximately 10 million innocent men, women, and children, he acted in complete agreement with the theory of evolution and in complete disagreement with everything humans know to be right and wrong . . . If you teach children that they evolved from monkeys, then they will act like monkeys.
An opposite response to the callousness of natural selection is to exult
in it, along with the Social Darwinists and - astonishingly - H. G. Wells.
The New Republic, where Wells outlines his Darwinian Utopia, contains
4 some blood-chilling lines:
A DEVIL'S CHAPLAIN
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And how will the New Republic treat the inferior races? How will it deal with the black? . . . the yellow man? . . . the Jew? . . . those swarms of black, and brown, and dirty-white, and yellow people, who do not come into the new needs of efficiency? Well, the world is a world, and not a charitable institution, and I take it they will have to go . . . And the ethical system of these men of the New Republic, the ethical system which will dominate the world state, will be shaped primarily to favour the procreation of what is fine and efficient and beautiful in humanity - beautiful and strong bodies, clear and powerful minds . . . And the method that nature has followed hitherto in the shaping of the world, whereby weakness was prevented from propagating weakness . . . is death . . . The men of the New Republic . . . will have an ideal that will make the killing worth the while.
Wells's colleague Julian Huxley downplayed, in effect, the pessimism of
the Devil's Chaplain as he tried to build an ethical system on what he
saw as evolution's progressive aspects. His 'Progress, Biological and
5
Other', the first of his Essays of a Biologist, almost like a call to arms under evolution's banner:
[man's] face is set in the same direction as the main tide of evolving life, and his highest destiny, the end towards which he has so long perceived that he must strive, is to extend to new possibilities the process with which, for all these millions of years, nature has already been busy, to introduce less and less wasteful methods, to accelerate by means of his consciousness what in the past has been the work of blind unconscious forces.
I prefer to stand up with Julian's refreshingly belligerent grandfather T. H. Huxley, agree that natural selection is the dominant force in bio- logical evolution unlike Shaw, admit its unpleasantness unlike Julian, and, unlike Wells, fight against it as a human being. Here is T. H. , in his
6 Romanes Lecture. in Oxford in 1893, on 'Evolution and Ethics':
Let us understand, once for all, that the ethical progress of society depends, not on imitating the cosmic process, still less in running away from it, but in combating it.
That is G. C. Williams's recommendation today, and it is mine. I hear the bleak sermon of the Devil's Chaplain as a call to arms. As an academic scientist I am a passionate Darwinian, believing that natural selection is, if not the only driving force in evolution, certainly the only known force capable of producing the illusion of purpose which so strikes all who contemplate nature. But at the same time as I support Darwinism as a scientist, I am a passionate anti-Darwinian when it
10
contains passages that read
? comes to politics and how we should conduct our human affairs. My previous books, such as The Selfish Gene and The Blind Watchmaker, extol the inescapable factual correctness of the Devil's Chaplain (had Darwin decided to extend the list of melancholy adjectives in the Chaplain's indictment, he would very probably have chosen both 'selfish' and 'blind'). At the same time I have always held true to the closing words of my first book, 'We, alone on earth, can rebel against the tyranny of the selfish replicators. '
If you seem to smell inconsistency or even contradiction, you are mistaken. There is no inconsistency in favouring Darwinism as an academic scientist while opposing it as a human being; any more than there is inconsistency in explaining cancer as an academic doctor while fighting it as a practising one. For good Darwinian reasons, evolution gave us a brain whose size increased to the point where it became capable of understanding its own provenance, of deploring the moral implications and of fighting against them. Every time we use contra- ception we demonstrate that brains can thwart Darwinian designs. If, as my wife suggests to me, selfish genes are Frankensteins and all life their monster, it is only we that can complete the fable by turning against our creators. We face an almost exact negation of Bishop Heber's lines, 'Though every prospect pleases, And only man is vile. ' Yes, man can be vile too, but we are the only potential island of refuge from the implications of the Devil's Chaplain: from the cruelty, and the clumsy, blundering waste.
For our species, with its unique gift of foresight - product of the simulated virtual-reality we call the human imagination - can plan the very opposite of waste with, if we get it right, a minimum of clumsy blunders. And there is true solace in the blessed gift of understanding, even if what we understand is the unwelcome message of the Devil's Chaplain. It is as though the Chaplain matured and offered a second half to the sermon. Yes, says the matured Chaplain, the historic process that caused you to exist is, wasteful, cruel and low. But exult in your existence, because that very process has blundered unwittingly on its own negation. Only a small, local negation, to be sure: only one species, and only a minority of the members of that species; but there lies hope.
Exult even more that the clumsy and cruel algorithm of natural
selection has generated a machine capable of internalizing the
algorithm, setting up a model of itself - and much more - in microcosm
inside the human skull. I may have disparaged Julian Huxley in these
pages, but he published a poem in 1926 which says something of what
8
I want to say (and a few things that I don't want to say):
7
A DEVIL'S CHAPLAIN
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The world of things entered your infant mind
To populate that crystal cabinet.
Within its walls the strangest partners met,
And things turned thoughts did propagate their kind. For, once within, corporeal fact could find
A spirit. Fact and you in mutual debt
Built there your little microcosm - which yet Had hugest tasks to its small self assigned.
Dead men can live there, and converse with stars: Equator speaks with pole, and night with day: Spirit dissolves the world's material bars -
A million isolations burn away.
The Universe can live and work and plan, At last made God within the mind of man.
9
This earth is one of the rare spots in the cosmos where mind has flowered. Man is a product of nearly three billion years of evolution, in whose person the evolutionary process has at last become conscious of itself and its possibilities. Whether he likes it or not, he is responsible for the whole further evolution of our planet.
Huxley's fellow luminary of the neo-Darwinian synthesis, the great
Russian-American geneticist Theodosius Dobzhansky said something
10 similar:
In giving rise to man, the evolutionary process has, apparently for the first and only time in the history of the Cosmos, become conscious of itself.
So, the Devil's Chaplain might conclude, Stand tall, Bipedal Ape. The shark may outswim you, the cheetah outrun you, the swift outfly you, the capuchin outclimb you, the elephant outpower you, the redwood outlast you. But you have the biggest gifts of all: the gift of under- standing the ruthlessly cruel process that gave us all existence; the gift of revulsion against its implications; the gift of foresight - something utterly foreign to the blundering short-term ways of natural selection - and the gift of internalizing the very cosmos.
We are blessed with brains which, if educated and allowed free rein, are capable of modelling the universe, with its physical laws in which the Darwinian algorithm is embedded. As Darwin himself put it, in the famous closing lines of the Origin of Species:
Julian Huxley later wrote, in his Essays of a Humanist:
12
? Thus, from the war of nature, from famine and death, the most exalted object which we are capable of conceiving, namely, the production of the higher animals, directly follows. There is grandeur in this view of life, with its several powers, having been originally breathed* into a few forms or into one; and that, whilst this planet has gone cycling on according to the fixed law of gravity, from so simple a beginning endless forms most beautiful and most wonderful have been, and are being, evolved.
There is more than just grandeur in this view of life, bleak and cold though it can seem from under the security blanket of ignorance. There is deep refreshment to be had from standing up full-face into the keen wind of understanding: Yeats's 'Winds that blow through the starry ways'. In another essay, I quote the words of an inspiring teacher, F. W. Sanderson, who urged his pupils to 'live dangerously . . . '
. . . full of the burning fire of enthusiasm, anarchic, revolutionary, energetic, daemonic, Dionysian, filled to overflowing with the terrific urge to create - such is the life of the man who risks safety and happiness for the sake of growth and happiness.
Safety and happiness would mean being satisfied with easy answers and cheap comforts, living a warm comfortable lie. The daemonic alterna- tive urged by my matured Devil's Chaplain is risky. You stand to lose comforting delusions: you can no longer suck at the pacifier of faith in immortality. To set against that risk, you stand to gain 'growth and happiness'; the joy of knowing that you have grown up, faced up to what existence means; to the fact that it is temporary and all the more precious for it. y
*In the Second Edition, and all subsequent editions of the Origin, the three words 'by the Creator' were interpolated at this point, presumably as a sop to religious sensibilities.
fNote added in proof: I was unaware, when I chose this title, that the BBC had used Darwin's phrase, 'Devil's Chaplain', for an excellent documentary based on Adrian Desmond and James Moore's biography.
A DEVIL'S CHAPLAIN
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What is True? 11
A little learning is a dangerous thing. This has never struck me as a particularly profound or wise remark,* but it comes into its own in the special case where the little learning is in philosophy (as it often is). A scientist who has the temerity to utter the t-word ('true') is likely to encounter a form of philosophical heckling which goes something like this:
There is no absolute truth. You are committing an act of personal faith when you claim that the scientific method, including mathematics and logic, is the privileged road to truth. Other cultures might believe that truth is to be found in a rabbit's entrails, or the ravings of a prophet up a pole. It is only your personal faith in science that leads you to favour your brand of truth.
That strand of half-baked philosophy goes by the name of cultural
relativism. It is one aspect of the Fashionable Nonsense detected by Alan 12
Sokal and Jean Bricmont, or the Higher Superstition of Paul Gross and 13
Norman Levitt. The feminist version is ably exposed by Daphne Patai
and Noretta Koertge, authors of Professing Feminism: Cautionary Tales
1 from the Strange World of Women's Studies: '
Women's Studies students are now being taught that logic is a tool of domination . . . the standard norms and methods of scientific inquiry are sexist because they are incompatible with 'women's ways of knowing'. . . These 'subjectivist' women see the methods of logic, analysis and abstraction as 'alien territory belonging to men' and 'value intuition as a safer and more fruitful approach to truth'.
How should scientists respond to the allegation that our 'faith' in logic
and scientific truth is just that - faith - not 'privileged' (favourite in-
word) over alternative truths? A minimal response is that science gets
ls results. As I put it in River Out ofEden,
*Pope's original is wonderful, but the aphorism doesn't survive isolation from its context. 14
? Show me a cultural relativist at 30,000 feet and I'll show you a hypocrite . . . If you are flying to an international congress of anthropologists or literary critics, the reason you will probably get there - the reason you don't plummet into a ploughed field - is that a lot of Western scientifically trained engineers have got their sums right.
Science boosts its claim to truth by its spectacular ability to make matter and energy jump through hoops on command, and to predict what will happen and when.
But is it still just our Western scientific bias to be impressed by accurate prediction; impressed by the power to slingshot rockets around Jupiter to reach Saturn, or intercept and repair the Hubble telescope; impressed by logic itself? Well, let's concede the point and think sociologically, even democratically. Suppose we agree, temporarily, to treat scientific truth as just one truth among many, and lay it alongside all the rival contenders: Trobriand truth, Kikuyu truth, Maori truth, Inuit truth, Navajo truth, Yanomamo truth, IKung San truth, feminist truth, Islamic truth, Hindu truth. The list is endless - and thereby hangs
a revealing observation.
In theory, people could switch allegiance from any one 'truth' to any
other if they decide it has greater merit. On what basis might they do so? Why would one change from, say, Kikuyu truth to Navajo truth? Such merit-driven switches are rare. With one crucially important excep- tion. Scientific truth is the only member of the list which regularly persuades converts of its superiority. People are loyal to other belief systems for one reason only: they were brought up that way, and they have never known anything better. When people are lucky enough to be offered the opportunity to vote with their feet, doctors and their kind prosper while witch doctors decline. Even those who do not, or cannot, avail themselves of a scientific education, choose to benefit from the technology that is made possible by the scientific education of others. Admittedly, religious missionaries have successfully claimed converts in great numbers all over the underdeveloped world. But they succeed not because of the merits of their religion but because of the science-based technology for which it is pardonably, but wrongly, given credit.
Surely the Christian God must be superior to our Juju, because Christ's representatives come bearing rifles, telescopes, chainsaws, radios, almanacs that predict eclipses to the minute, and medicines that work.
WHAT IS TRUE?
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So much for cultural relativism. A different type of truth-heckler prefers to drop the name of Karl Popper or (more fashionably) Thomas Kuhn:
There is no absolute truth. Your scientific truths are merely hypotheses that have so far failed to be falsified, destined to be superseded. At worst, after the next scientific revolution, today's 'truths' will seem quaint and absurd, if not actually false. The best you scientists can hope for is a series of approximations which progressively reduce errors but never eliminate them.
The Popperian heckle partly stems from the accidental fact that philosophers of science are traditionally obsessed with one piece of scientific history: the comparison between Newton's and Einstein's theories of gravitation. It is true that Newton's inverse square law has turned out to be an approximation, a special case of Einstein's more general formula. If this is the only piece of scientific history you know, you might indeed conclude that all apparent truths are mere approxi- mations, fated to be superseded. There is even a quite interesting sense in which all our sensory perceptions - the 'real' things that we 'see with our own eyes' - may be regarded as unfalsified 'hypotheses' about the world, vulnerable to change. This provides a good way to think about illusions such as the Necker Cube.
The flat pattern of ink on paper is compatible with two alternative 'hypotheses' of solidity. So we see a solid cube which, after a few seconds, 'flips' to a different cube, then flips back to the first cube, and so on. Perhaps sense data only ever confirm or reject mental 'hypotheses'
16 about what is out there.
Well, that is an interesting theory; so is the philosopher's notion that science proceeds by conjecture and refutation; and so is the analogy between the two. This line of thought - all our percepts are hypo- thetical models in the brain - might lead us to fear some future blurring of the distinction between reality and illusion in our descendants, whose lives will be even more dominated by computers capable of
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? generating vivid models of their own. Without venturing into the high- tech worlds of virtual reality, we already know that our senses are easily deceived. Conjurors - professional illusionists - can persuade us, if we lack a sceptical foothold in reality, that something supernatural is going on. Indeed, some notorious erstwhile conjurors make a fat living doing exactly that: a living much fatter than they ever enjoyed when they frankly admitted that they were conjurors. * Scientists, alas, are not best equipped to unmask telepathists, mediums and spoon-bending charlatans. This is a job which is best handed over to the professionals, and that means other conjurors. The lesson that conjurors, the honest variety and the impostors, teach us is that an uncritical faith in our own senses is not an infallible guide to truth.
But none of this seems to undermine our ordinary concept of what it means for something to be true. If I am in the witness box, and prosecuting counsel wags his stern finger and demands, 'Is it or is it not true that you were in Chicago on the night of the murder? ', I should get pretty short shrift if I said,
What do you mean by true? The hypothesis that I was in Chicago has not so far been falsified, but it is only a matter of time before we see that it is a mere approximation.
Or, reverting to the first heckle, I would not expect a jury, even a Bongolese jury, to give a sympathetic hearing to my plea that,
It is only in your western scientific sense of the word 'in' that I was in Chicago. The Bongolese have a completely different concept of 'in', according to which you are only truly 'in' a place if you are an anointed elder entitled to take snuff from the dried scrotum of a goat.
It is simply true that the Sun is hotter than the Earth, true that the desk on which I am writing is made of wood. These are not hypotheses awaiting falsification; not temporary approximations to an ever-elusive truth; not local truths that might be denied in another culture. And the same can safely be said of many scientific truths, even where we can't see them 'with our own eyes'. It is forever true that DNA is a double helix, true that if you and a chimpanzee (or an octopus or a kangaroo)
'Performing psychics and mystics, who happily perform in front of scientists, will con- veniently plead a headache and refuse to go on if informed that a contingent of professional conjurors is in the front row of the stalls. It is for the same reason that the then Editor of Nature, John Maddox, took James 'The Amazing' Randi with him when investigating a suspected case of homeopathic fraud. This caused some resentment at the time, but it was an entirely reasonable decision. Any genuine scientist has nothing to fear from a sceptical conjuror looking over his shoulder.
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trace your ancestors back far enough you will eventually hit a shared ancestor. To a pedant, these are still hypotheses which might be falsified tomorrow. But they never will be. Strictly, the truth that there were no human beings in the Jurassic Period is still a conjecture, which could be refuted at any time by the discovery of a single fossil, authentically dated by a battery of radiometric methods. It could happen. Want a bet? Even if they are nominally hypotheses on probation, these statements are true in exactly the same sense as the ordinary truths of everyday life; true in the same sense as it is true that you have a head, and that my desk is wooden. If scientific truth is open to philosophic doubt, it is no more so than common sense truth. Let's at least be even-handed in our philosophical heckling.
A more profound difficulty now arises for our scientific concept of truth. Science is very much not synonymous with common sense. Admittedly, that doughty scientific hero T. H. Huxley said:
Science is nothing but trained and organized common sense, differing from the latter only as a veteran may differ from a raw recruit: and its methods differ from those of common sense only as far as the guardsman's cut and thrust differ from the manner in which a savage wields his club.
But Huxley was talking about the methods of science, not its conclusions. As Lewis Wolpert emphasized in The Unnatural Nature of
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Science, the conclusions can be disturbingly counter-intuitive.
Quantum theory is counter-intuitive to the point where the physicist sometimes seems to be battling insanity. We are asked to believe that a single quantum behaves like a particle in going through one hole instead of another, but simultaneously behaves like a wave in interfer- ing with a non-existent copy of itself, if another hole is opened through which that non-existent copy could have travelled (if it had existed). It gets worse, to the point where some physicists resort to a vast number of parallel but mutually unreachable worlds, which proliferate to accommodate every alternative quantum event; while other physicists, equally desperate, suggest that quantum events are determined retro- spectively by our decision to examine their consequences. Quantum theory strikes us as so weird, so defiant of common sense, that even the great Richard Feynman was moved to remark, T think I can safely say that nobody understands quantum mechanics. ' Yet the many predic- tions by which quantum theory has been tested stand up, with an accuracy so stupendous that Feynman compared it to measuring the distance between New York and Los Angeles accurately to the width of one human hair. On the basis of these stunningly successful
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? predictions, quantum theory, or some version of it, seems to be as true as anything we know.
Modern physics teaches us that there is more to truth than meets the eye; or than meets the all too limited human mind, evolved as it was to cope with medium-sized objects moving at medium speeds through medium distances in Africa. In the face of these profound and sublime mysteries, the low-grade intellectual poodling of pseudo-philosophical poseurs seems unworthy of adult attention.
WHAT IS TRUE?
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? Gaps in the Mind
Sir,
You appeal for money to save the gorillas. Very laudable, no doubt. But it doesn't seem to have occurred to you that there are thousands of human children suffering on the very same continent of Africa. There'll be time enough to worry about gorillas when we've taken care of every last one of the kiddies. Let's get our priorities right, p/ease!
This hypothetical letter could have been written by almost any well- meaning person today. In lampooning it, I don't mean to imply that a good case could not be made for giving human children priority. I expect
it could, and also that a good case could be made the other way. I'm only trying to point the finger at the automatic, unthinking nature of the speciesist double standard. To many people it is simply self-evident, without any discussion, that humans are entitled to special treatment. To see this, consider the following variant on the same letter:
Sir,
You appeal for money to save the gorillas. Very laudable, no doubt. But it doesn't seem to have occurred to you that there are thousands of aardvarks suffering on the very same continent of Africa. There'll be time enough to worry about gorillas when we've saved every last one of the aardvarks. Let's get our priorities right, p/ease!
This second letter could not fail to provoke the question: What's so special about aardvarks? A good question, and one to which we should require a satisfactory answer before we took the letter seriously. Yet the first letter, I suggest, would not for most people provoke the equivalent question, 'What's so special about humans? ' As I said, I don't deny that this question, unlike the aardvark question, very probably has a power- ful answer. All that I am criticizing is an unthinking failure to realize in the case of humans that the question even arises.
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? The speciesist* assumption that lurks here is very simple. Humans are humans and gorillas are animals. There is an unquestioned yawning gulf between them such that the life of a single human child is worth more than the lives of all the gorillas in the world. The 'worth' of an animal's life is just its replacement cost to its owner - or, in the case of
a rare species, to humanity. But tie the label Homo sapiens even to a tiny piece of insensible, embryonic tissue, and its life suddenly leaps to infinite, uncomputable value.
This way of thinking characterizes what I want to call the discontinuous mind. We'd all agree that a six-foot woman is tall, and a five-foot woman is not. Words like 'tall' and 'short' tempt us to force the world into qualitative classes, but this doesn't mean that the world really is discontinuously distributed. Were you to tell me that a woman is five feet nine inches tall, and ask me to decide whether she should therefore be called tall or not, I'd shrug and say, 'She's five foot nine, doesn't that tell you what you need to know? ' But the discontinuous mind, to caricature it a little, would go to court to decide (probably at great expense) whether the woman was tall or short. Indeed, I hardly need to say caricature. For years, South African courts have done a brisk trade adjudicating whether particular individuals of mixed parentage count as white, black or 'coloured'. t
The discontinuous mind is ubiquitous. It is especially influential when it afflicts lawyers and the religious (not only are all judges lawyers; a high proportion of politicians are too, and all politicians have to woo the religious vote). Recently, after giving a public lecture, I was cross-examined by a lawyer in the audience. He brought the full weight of his legal acumen to bear on a nice point of evolution. If species A evolves into a later species B, he reasoned closely, there must come a point when a mother belongs to the old species A and her child belongs to the new species B. Members of different species cannot interbreed with one another. I put it to you, he went on, that a child could hardly be so different from its parents that it could not interbreed with their kind. So, he wound up triumphantly, isn't this a fatal flaw in the theory of evolution?
But it is we that choose to divide animals up into discontinuous species. On the evolutionary view of life there must have been inter- mediates, even though, conveniently for our naming rituals, they are today usually extinct. They are not always extinct. The lawyer would be
'Coined by Richard Ryder and given currency by Peter Singer, the analogy is to racism. tThankfully no longer. The apartheid regime is one of history's monuments to the tyranny of the discontinuous mind.
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surprised and, I hope, intrigued by so-called 'ring species'. The best- known case is the Herring Gull/Lesser Black-backed Gull ring. In Britain these are clearly distinct species, quite different in colour. Anybody can tell them apart. But if you follow the population of Herring Gulls westward round the North Pole to North America, then via Alaska across Siberia and back to Europe again, you notice a curious fact. The 'Herring Gulls' gradually become less and less like Herring Gulls and more and more like Lesser Black-backed Gulls until it turns out that our European Lesser Black-backed Gulls actually are the other end of a ring that started out as Herring Gulls. At every stage around the ring, the birds are sufficiently similar to their neighbours to interbreed with them. Until, that is, the ends of the continuum are reached, in Europe. At this point the Herring Gull and the Lesser Black-backed Gull never interbreed, although they are linked by a continuous series of interbreeding colleagues all the way round the world. The only thing that is special about ring species like these gulls is that the intermediates are still alive. All pairs of related species are potentially ring species. The intermediates must have lived once. It is just that in most cases they are now dead.
The lawyer, with his trained discontinuous mind, insists on placing individuals firmly in this species or that. He does not allow for the possibility that an individual might lie halfway between two species, or a tenth of the way from species A to species B. Self-styled 'pro-lifers', and others that indulge in footling debates about exactly when in its development a foetus 'becomes human', exhibit the same discon- tinuous mentality. It is no use telling these people that, depending upon the human characteristics that interest you, a foetus can be 'half human' or 'a hundredth human'. 'Human', to the discontinuous mind, is an absolutist concept. There can be no half measures. And from this flows much evil.
The word 'apes' usually means chimpanzees, gorillas, orang utans, gibbons and siamangs. We admit that we are like apes, but we seldom realize that we are apes. Our common ancestor with the chimpanzees and gorillas is much more recent than their common ancestor with the Asian apes - the gibbons and orang utans. There is no natural category that includes chimpanzees, gorillas and orangs but excludes humans. The artificiality of the category 'apes', as conventionally taken to exclude humans, is demonstrated by the following diagram. The family tree shows humans to be in the thick of the ape cluster; the artificiality of the conventional category 'ape' is shown by the stippling.
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? Gibbon
Siamang
Gorilla
Pigmy Chimpanzee Chimpanzee Human
I Orang Utan
- 'APES'
In truth, not only are we apes, we are African apes. The category 'African apes', if you don't arbitrarily exclude humans, is a natural category. The stippled area doesn't have any artificial 'bites' taken out of it:
Gibbon
Siamang
Gorilla
Pigmy Chimpanzee Chimpanzee Human
i Orang Utan
- AFRICAN APES
All the African apes that have ever lived, including ourselves, are linked to one another by an unbroken chain of parent-child bonds. The same is true of all animals and plants that have ever lived, but there the distances involved are much greater. Molecular evidence suggests that our common ancestor with chimpanzees lived, in Africa, between 5 and 7 million years ago, say half a million generations ago. This is not long by evolutionary standards.
Happenings are sometimes organized at which thousands of people hold hands and form a human chain, say from coast to coast of the United States, in aid of some cause or charity. Let us imagine setting one up along the equator, across the width of our home continent of Africa. It is a special kind of chain, involving parents and children, and we'll have to play tricks with time in order to imagine it. You stand on the shore of the Indian Ocean in southern Somalia, facing north, and in
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your left hand you hold the right hand of your mother. In turn she holds the hand of her mother, your grandmother. Your grandmother holds her mother's hand, and so on. The chain wends its way up the beach, into the arid scrubland and westwards on towards the Kenya border.
How far do we have to go until we reach our common ancestor with the chimpanzees? It's a surprisingly short way. Allowing one yard per person, we arrive at the ancestor we share with chimpanzees in under 300 miles. We've hardly started to cross the continent; we're still not half way to the great Rift Valley. The ancestor is standing well to the east of Mount Kenya, and holding in her hand an entire chain of her lineal descendants, culminating in you standing on the Somali beach.
The daughter that she is holding in her right hand is the one from whom we are descended. Now the arch-ancestress turns eastward to face the coast, and with her left hand grasps her other daughter, the one from whom the chimpanzees are descended (or son, of course, but let's stick to females for convenience). The two sisters are facing one another, and each holding their mother by the hand. Now the second daughter, the chimpanzee ancestress, holds her daughter's hand, and a new chain is formed, proceeding back towards the coast. First cousin faces first cousin, second cousin faces second cousin, and so on. By the time the folded-back chain has reached the coast again, it consists of modern chimpanzees. You are face to face with your chimpanzee cousin, and you are joined to her by an unbroken chain of mothers holding hands with daughters. If you walked up the line like an inspecting general - past Homo erectus, Homo habilis, perhaps Australopithecus afarensis - and down again the other side (the intermediates on the chimpanzee side are unnamed because, as it happens, no fossils have been found), you would nowhere find any sharp discontinuity. Daughters would resemble mothers just as much (or as little) as they always do. Mothers would love daughters, and feel affinity with them, just as they always do. And this hand-in-hand continuum, joining us seamlessly to chimpanzees, is so short that it barely makes it past the hinterland of Africa, the mother continent.
Our chain of African apes in time, doubling back on itself, is in miniature like the ring of gulls in space, except that the intermediates happen to be dead. The point I want to make is that, as far as morality is concerned, it should be incidental that the intermediates are dead. What if they were not? What if a clutch of intermediate types had survived, enough to link us to modern chimpanzees by a chain, not just of hand-holders, but of interbreeders? Remember the song, 'I've danced
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?
