Science in the Soul

by Richard Dawkins

  The next piece, ‘Who would rally against reason?’, issues a rousing invitation to the Reason Rally in Washington DC, beginning with a hymn to the achievements of reason and ending with another call to arms in its defence. If that piece leaves some British readers feeling slightly smug, the next, ‘In praise of subtitles; or, a drubbing for dubbing’, should banish any such self-satisfaction in a great many of us who listen in awe to the fluency of Europeans speaking English. This is more than a bewailing of a national shortcoming: harnessing scientific imagination to real-world observation, it suggests reasons beyond laziness or the long imperial shadow and makes fascinating proposals for redress.

  So many problems to be tackled, so many obstacles in the way: no wonder a writer of intellectual heft, imaginative reach and strong public engagement gets frustrated at times. The final piece in this section gives just one small glimpse of what might happen if Richard Dawkins ruled the world…

  G.S.

  The dead hand of Plato*1

  WHAT PERCENTAGE OF the British population lives below the poverty line? When I call that a silly question, a question that doesn’t deserve an answer, I’m not being callous or unfeeling about poverty. I care very much if children starve or pensioners shiver with cold. My objection – and this is just one of many examples – is to the very idea of a line: a gratuitously manufactured discontinuity in a continuous reality.

  Who decides how poor is poor enough to qualify as below the ‘poverty line’? What is to stop us moving the line and thereby changing the score? Poverty/wealth is a continuously distributed quantity, which might be measured as, say, income per week. Why throw away most of the information by splitting a continuous variable into two discontinuous categories: above and below the ‘line’? How many of us lie below the stupidity line? How many runners exceed the fast line? How many Oxford undergraduates lie above the first-class line?

  Yes, we in universities do it too. Examination performance, like most measures of human ability or achievement, is a continuous variable, whose frequency distribution is bell-shaped. Yet British universities insist on publishing a class list, in which a minority of students receive first-class degrees, rather a lot obtain seconds (nowadays subdivided into upper and lower seconds), and a few get thirds. That might make sense if the distribution had three or four peaks with deep valleys in between, but it doesn’t. Anybody who has ever marked an exam knows that the bottom of one class is separated from the top of the class below by a small fraction of the distance that separates it from the top of its own class. This fact alone points to a deep unfairness in the system of discontinuous classification.

  Examiners go to great trouble to assign a score, perhaps out of 100, to each exam script. Scripts are double- or even triple-marked by different examiners, who may then argue the nuances of whether an answer deserves 55 or 52 marks. Marks are scrupulously added up, normalized, transformed, juggled and fought over. The final marks that emerge, and the rank orders of students, are as richly informative as conscientious examiners can achieve. But then what happens to all that richness of information? Most of it is thrown away, in reckless disregard for all the labour and nuanced deliberation and adjusting that went into the marking process. The students are bundled into three or four discrete classes, and that is all the information that penetrates outside the examiners’ room.

  Cambridge mathematicians, as one might expect, finesse the discontinuity and leak the rank order. It became informally known that Jacob Bronowski was the ‘Senior Wrangler’ of his year, Bertrand Russell the Seventh Wrangler of his year and so on. At other universities, too, tutors’ testimonials may say things like, ‘Not only did she get a first: I can tell you in confidence that the examiners ranked her number 3 of her entire class of 106 in the university.’ That is the kind of information that really counts in a letter of recommendation. And it is that very information that is wantonly thrown away in the officially published class list.

  Perhaps such wastage of information is inevitable: a necessary evil. I don’t want to make too much of it. What is more serious is that there are some educators – dare I say especially in non-scientific subjects – who fool themselves into believing that there is a kind of Platonic ideal called the ‘First Class Mind’ or ‘Alpha Mind’: a qualitatively distinct category, as distinct as female is from male, or sheep from goat. This is an extreme form of what I am calling the discontinuous mind. It can probably be traced to the ‘essentialism’ of Plato – one of the most pernicious ideas in all history.

  Plato took his characteristically Greek geometer’s view of things and forced it where it didn’t belong. For Plato, a circle, or a right triangle, was an ideal form, definable mathematically but never realized in practice. A circle drawn in the sand was an imperfect approximation to the ideal Platonic circle hanging in some abstract space. That works for geometric shapes like circles; but essentialism has been applied to living things, and Ernst Mayr blamed this for humanity’s late discovery of evolution – as late as the nineteenth century. If you treat all flesh-and-blood rabbits as imperfect approximations to an ideal Platonic rabbit, it won’t occur to you that rabbits might have evolved from a non-rabbit ancestor, and might evolve into a non-rabbit descendant. If you think, following the dictionary definition of essentialism, that the essence of rabbitness is ‘prior to’ the existence of rabbits (whatever ‘prior to’ might mean, and that’s a nonsense in itself) evolution is not an idea that will spring readily to your mind, and you may resist when somebody else suggests it.

  For legal purposes, say in deciding who can vote in elections, we need to draw a line between adult and non-adult. We may dispute the rival merits of eighteen versus twenty-one or sixteen, but everybody accepts that there has to be a line, and the line must be a birthday. Few would deny that some fifteen-year-olds are better qualified to vote than some forty-year-olds. But we recoil from the voting equivalent of a driving test, so we accept the age line as a necessary evil. But perhaps there are other examples where we should be less willing to do so. Are there cases where the tyranny of the discontinuous mind leads to real harm: cases where we should actively rebel against it? Yes.

  Essentialism bedevils moral controversies such as those over abortion and euthanasia. At what point is a brain-dead accident victim defined as ‘dead’? At what moment during development does an embryo become a ‘person’? Only a mind infected with essentialism would ask such questions. An embryo develops gradually from single-celled zygote to newborn baby, and there’s no single instant when ‘personhood’ should be deemed to have arrived. The world is divided into those who get this truth and those who wail: ‘But there has to be some moment when the fetus becomes human.’ No, there really doesn’t, any more than there has to be a day when a middle-aged person becomes old. It would be better – though still not ideal – to say the embryo goes through stages of being a quarter human, half human, three-quarters human…The essentialist mind will recoil from such language and accuse me of all manner of horrors for denying the essence of humanness.

  There are those who cannot distinguish a sixteen-cell embryo from a baby. They call abortion murder, and feel righteously justified in committing real murder against a doctor – a thinking, feeling, sentient adult, with a loving family to mourn him. The discontinuous mind is blind to intermediates. An embryo is either human or it isn’t. Everything is this or that, yes or no, black or white. But reality isn’t like that.

  For purposes of legal clarity, just as the eighteenth birthday is defined as the moment of getting the vote, it may be necessary to draw a line at some arbitrary moment in embryonic development after which abortion is prohibited. But personhood doesn’t spring into existence at any one moment: it matures gradually, and it goes on maturing through childhood and beyond.

  To the discontinuous mind, an entity either is a person or is not. The discontinuous mind cannot grasp the idea of a half person, or a three-quarters person. Some absolutists go right back to conception as the moment when the person co
mes into existence – the instant the soul is injected – so all abortion is murder by definition. The Catholic Doctrine of the Faith entitled Donum Vitae says:

  From the time that the ovum is fertilized, a new life is begun which is neither that of the father nor of the mother; it is rather the life of a new human being with his own growth. It would never be made human if it were not human already. To this perpetual evidence…modern genetic science brings valuable confirmation. It has demonstrated that, from the first instant, the program is fixed as to what this living being will be: a man, this individual-man with his characteristic aspects already well determined. Right from fertilization is begun the adventure of a human life…*2

  It is amusing to tease such absolutists by confronting them with a pair of identical twins (they split after fertilization, of course) and asking which twin got the soul, which twin is the non-person: the zombie. A puerile taunt? Maybe. But it hits home because the belief that it destroys is puerile. And ignorant.

  ‘It would never be made human if it were not human already.’ Really? Are you serious? Nothing can become something if it is not that something already? Is an acorn an oak tree? Is a hurricane the barely perceptible zephyr that seeds it? Would you apply your doctrine to evolution too? Do you suppose there was a moment in evolutionary history when a non-person gave birth to the first person?

  Paleontologists will argue passionately about whether a particular fossil is, say, Australopithecus or Homo. But any evolutionist knows there must have existed individuals who were exactly intermediate. It’s essentialist folly to insist on shoehorning your fossil into one genus or the other. There never was an Australopithecus mother who gave birth to a Homo child, for every child ever born belonged to the same species as its mother. The whole system of labelling species with discontinuous names is geared to a time slice, such as the present, in which ancestors have been conveniently expunged from our awareness. If by some miracle every ancestor were preserved as a fossil, discontinuous naming would be impossible.*3 Creationists are misguidedly fond of citing ‘gaps’ as embarrassing for evolutionists, but gaps are a fortuitous boon for taxonomists who, with good reason, want to give species discrete names. Quarrelling about whether a fossil is ‘really’ Australopithecus or Homo is like quarrelling over whether George should be called ‘tall’. He’s five foot ten, doesn’t that tell you what you need to know?

  If a time machine could serve up to you your 200-million-greats-grandfather, you would eat him with sauce tartare and a slice of lemon. He was a fish. Yet you are connected to him by an unbroken line of intermediate ancestors, every one of whom belonged to the same species as its parents and its children.

  ‘I’ve danced with a man who’s danced with a girl who’s danced with the Prince of Wales,’ as the song goes. I could mate with a woman, who could mate with a man, who could mate with a woman who…after a sufficient number of steps…could mate with an ancestral fish, and produce fertile offspring. To invoke our time machine again, you could not mate with Australopithecus (at least, the pairing would not produce fertile offspring) but you are connected to Australopithecus by an unbroken chain of intermediates who could interbreed with their neighbours in the chain every step of the way. And the chain goes on backwards, unbroken, to that fish of the Devonian period and beyond. But for the extinction of the intermediates which connect humans to the ancestor we share with pigs (it pursued its shrew-like existence eighty-five million years ago in the shadow of the dinosaurs), and but for the extinction of the intermediates that connect the same ancestor to modern pigs, there would be no clear separation between Homo sapiens and Sus scrofa. You could breed with X who could breed with Y who could breed with (... fill in several thousand intermediates…) who could produce fertile offspring by mating with a sow.

  It is only the discontinuous mind that insists on drawing a hard and fast line between a species and the ancestral species that birthed it. Evolutionary change is gradual: there never was a line between any species and its evolutionary precursor.*4

  In a few cases the intermediates have failed to go extinct, and the discontinuous mind really is faced with the problem in stark reality. Herring gulls (Larus argentatus) and lesser black-backed gulls (Larus fuscus) breed in mixed colonies in western Europe and don’t interbreed. This defines them as good, separate species. But if you travel in a westerly direction around the northern hemisphere and sample the gulls as you go, you find that the local gulls vary from the light grey of the herring gull, getting gradually darker as you progress around the North Pole, until eventually, when you go all the way round to western Europe again, they have darkened so far that they ‘become’ lesser black-backed gulls. What’s more, the neighbouring populations interbreed with each other all the way around the ring, even though the ends of the ring, the two species we see in Britain, don’t interbreed. Are they distinct species or not? Only those tyrannized by the discontinuous mind feel obliged to answer that question. If it were not for the accidental extinction of evolutionary intermediates, every species would be linked to every other by interbreeding chains like these gulls.

  Essentialism rears its ugly head in racial terminology. The majority of ‘African Americans’ are of mixed race. Yet so entrenched is our essentialist mindset, American official forms require everyone to tick one race/ethnicity box or another: no room for intermediates. In the United States today, a person will be called ‘African American’ even if only, say, one of his eight great-grandparents was of African descent.

  Colin Powell and Barack Obama are described as black. They do have black ancestors, but they also have white ancestors, so why don’t we call them white? It is a weird convention that the descriptor ‘black’ behaves as the cultural equivalent of a genetic dominant. Gregor Mendel, the father of genetics, crossed wrinkled and smooth peas and the offspring were all smooth: smoothness is ‘dominant’. When a white person breeds with a black person the child is intermediate but is labelled ‘black’: the cultural label is transmitted down the generations like a dominant gene, and this persists even to cases where, say, only one out of eight great-grandparents was black and it may not show in skin colour at all. It is the racist ‘contamination metaphor’ (as Lionel Tiger pointed out to me), the ‘touch of the tarbrush’. Our language lacks the equivalent ‘touch of whitewash’ and is ill-equipped to deal with a continuum of intermediates. Just as people must lie below or above the poverty ‘line’, so we classify people as ‘black’ even if they are in fact intermediate. When an official form invites us to tick a ‘race’ or ‘ethnicity’ box I recommend crossing it out and writing ‘human’.

  In US presidential elections every state (except Maine and Nebraska) has to end up labelled either Democrat or Republican, no matter how evenly divided the voters in that state might be. Each state sends to the Electoral College a number of delegates which is proportional to the population of the state. So far so good. But the discontinuous mind insists that all the delegates from a given state have to vote the same way. This ‘winner-take-all’ system was shown up in all its fatuity in the 2000 election when there was a dead heat in Florida. Al Gore and George Bush received the same number of votes as each other, the tiny, disputed difference being well within the margin of error. Florida sends twenty-five delegates to the Electoral College.*5 The Supreme Court was asked to decide which candidate should receive all twenty-five votes (and therefore the presidency). Since it was a dead heat, it might have seemed reasonable to allot thirteen votes to one candidate and twelve to the other. It would have made no difference whether Bush or Gore received the thirteen votes: either way Gore would have been President. Indeed, Gore could have given Bush twenty-two of the twenty-five Electoral College delegates and still won the presidency.

  I am not saying the Supreme Court should actually have split the Florida delegates. They had to abide by the rules, no matter how idiotic. I would say that, given the lamentable constitutional rule that the twenty-five votes had to be bound together as a one-party block, natural
justice should have led the court to allocate the twenty-five votes to the candidate who would have won the election if the Florida delegates had been divided, namely Gore. But that is not the point I am making here. My point here is that the winner-take-all idea of an Electoral College in which each state has an indivisible block of members, either all Democrat or all Republican no matter how close the vote, is a shockingly undemocratic manifestation of the tyranny of the discontinuous mind. Why is it so hard to admit that there are intermediates, as Maine and Nebraska do? Most states are not ‘red’ or ‘blue’ but a complex mixture.*6

  Scientists are called upon by governments, by courts of law, and by the public at large, to give a definite, absolute, yes-or-no answer to important questions, for example questions of risk. Whether it’s a new medicine, a new weedkiller, a new power station or a new airliner, the scientific ‘expert’ is peremptorily asked: Is it safe? Answer the question! Yes or no? Vainly the scientist tries to explain that safety and risk are not absolutes. Some things are safer than others, and nothing is perfectly safe. There is a sliding scale of intermediates and probabilities, not hard-and-fast discontinuities between safe and unsafe. That is another story and I have run out of space.

  But I hope I have said enough to suggest that the summary demand for an absolute yes-or-no answer, so beloved of journalists, politicians and finger-wagging, hectoring lawyers, is yet another unreasonable expression of a kind of tyranny, the tyranny of the discontinuous mind, the dead hand of Plato.

  * * *

  *1 I was invited to be guest editor of New Statesman for the Christmas double issue of 2011. This article is largely taken from ‘The tyranny of the discontinuous mind’, which was my essay in that issue, but also incorporates parts of my chapter, ‘Essentialism’, in John Brockman’s edited volume This Idea Must Die: scientific theories that are blocking progress.