From Descartes to Darwin
Though writers, philosophers and social scientists have been denying the existence of an essential core of humanity for the best part of a century, the debate on human nature has now entered a new phase. Modern science’s engagement with human nature can be traced back to the Enlightenment, when, as we’ve seen, reason rather than revelation or tradition finally came to dominate the natural sciences. But did ‘nature’ include humanity? The earliest scientists and philosophers were ambivalent. In René Descartes’ mechanistic philosophy the world was divided into matter and mind. Descartes proposed that animals were made of matter – elaborate machines, different in complexity but not in principle, from the fairground automata of his day. This in itself was a revolutionary step because it placed the examination of living creatures outside the domain of religion allowing their study to become a secular science. But even Descartes could not accept that humans were no different, in principle, from a cuckoo clock, so he proposed dualism, the theory that although the human body is made of matter and driven by corporeal pulleys, pumps and levers; our conscious actions were driven by a spiritual soul. Descartes even went on to propose a seat for the soul in the tiny pineal gland deep in the brain (he couldn’t accept a duplicated soul and it was the only structure he could find in the brain that wasn’t duplicated across the hemispheres). It was this soul, with its higher feelings and direct connection to the divine that was, in Descartes’ philosophy, the source of human nature and what separated us from lowly animals.
There were of course problems with dualism, most famously the nature of the causal connection between an ethereal soul and a physical body: the mind-body problem. Yet dualism was a great asset to the pioneer biologists since it allowed them to study the mechanisms of the natural world without treading on the sensitive toes of religious orthodoxy. Linnaeus could begin the monumental task of classifying nature by gathering all living creatures under a single binomial umbrella; Hunter could dissect the sinews of corpses to reveal human anatomy; Louis Pasteur could peer into the microscopic world and discover the hidden agents of disease. All these enterprises could proceed without incurring the wrath of the church because most biologists remained committed dualists, content to unravel the mechanisms of the world but not daring to investigate into the device that performed the unravelling.
The first chink in the dualist armour came with the recognition that the gap between animals and us was not so great after all. When Darwin’s apes climbed down from the trees they brought with them all those mechanisms that were assumed to drive animal behaviour [plural to avoid non-pc pronouns – fine]. It wasn’t long before scientists started to think the previously unthinkable. If humankind had once been a mechanistic animal, was it likely that they had left all those mechanisms up in the trees? Perhaps the stream of consciousness itself may have a physical, rather than a spiritual source?
Scientific dualism quickly went the way of spontaneous generation, vitalism and other theories that sought to explain the wonders of the natural world by inserting a magical, spiritual or mystical ingredient. With Darwin’s publication of The Descent of Man and The Expression of Emotions in Man and Animals the way was cleared for a fully scientific enquiry into the nature of Humanity. The creator of science, also became its subject.
But then came eugenics. Rarely covered in textbooks, eugenics is biology’s dirty secret. Although its roots go deep, at least as far back as Plato’s Republic, there is no doubt that its popularity in the late nineteenth and early twentieth century owed much to its supposed scientific credentials within the framework of Darwinian natural selection. Survival of the fittest is of course eugenics au natural. Darwin recognised that the consequences of Nature’s eugenics policy over thousands of generations was evolution. Darwin himself (perhaps deeply affected by the loss of his own daughter four years earlier) lamented natural selection’s ‘clumsy, wasteful, blundering, low, and horribly cruel’ action. But if human nature was malleable and could be shaped by Nature, couldn’t man do better? Many of Darwin’s contemporaries, such as his cousin the geneticist Francis Galton, sought to improve on natural selection with programmes that promoted breeding of those who possessed ‘goodness of constitution, of physique and mental capacity’. From its inception, the eugenics movement was openly racist, with the aim of ensuring that the ‘feeble nations’ give way before the ‘nobler varieties of mankind’. There was never any doubt as to the identity of the ‘nobler varieties’ who were of course the white Anglo-Saxon middle and upper class intellectuals who thronged into the eugenics society meeting rooms.
The blame for the eugenics movement cannot, however, be laid solely at the door of the scientific establishment. Eugenics may have been the bastard progeny of the theory of natural selection but the infant pseudoscience was enthusiastically adopted by many of the leading intellectuals, writers, politicians, economists and social reformers of the day. In November 1913 the Oxford University Union carried a motion by 105 votes to 66 that ‘this house approves the principles of eugenics’. As a cabinet minister, the young Winston Churchill advocated compulsory sterilization of ‘the feeble minded and insane classes’. H.G. Wells frequently promoted eugenics. George Bernard Shaw wrote, ‘being cowards, we defeat natural selection under cover of philanthropy: being sluggards, we neglect artificial selection under cover of delicacy and morality’. In 1915 Virginia Woolf wrote in her diary: ‘On the towpath we met & had to pass a long line of imbeciles. The first was a very tall young man, just queer enough to look twice at, but no more; the second shuffled, & looked aside; & then one realised that every one in that long line was a miserable ineffective shuffling idiotic creature, with no forehead, or no chin, & an imbecile grin, or a wild suspicious stare. It was perfectly horrible. They should certainly be killed’.
In truth, popular support for eugenics amongst the West European and US intelligentsia had very little to do with its dubious scientific credentials. Its wellsprings were far more to do with the middle and upper class fear of the burgeoning populations of the poor. For Churchill’s ‘insane classes’ read working classes, and when Francis Galton advocated breeding from ‘those only of the best stock’, it was obvious to everyone who was to be left out. The contraception pioneer Marie Stopes campaigned to pass laws to enable sterilisation of the ‘hopelessly rotten and racially diseased’.
Many European countries and US states adopted eugenicist sterilization policies. Even in liberal Sweden, more than 62,000 people (mostly women) with physical or mental handicap, or considered merely to be socially ‘undesirable’, were sterilized against their will. The full horror of eugenicist policies were realized in the 1934 German racial hygiene law that led to the enforced sterilization of more than 80,000 individuals considered by the ‘hereditary health courts’ to be ‘lives unworthy of life’. Although in reality only peripheral to the terrors of Nazi Germany, Hitler’s enthusiastic support of its principles as a means of engineering the master race established eugenics as the pariah of post-war science.
With the discrediting of eugenics in the years following the Second World War, any scientific investigation of the biological roots of human nature took a similar fall from grace. Behavioural biologists retreated into the forest to study chimpanzees, ants, or monkeys, and the field of study of human social behaviour was left to anthropologists and sociologists. A new dualism emerged with culture replacing Descartes’ soul as the primary mover of the human mind.
Genes versus culture
As discussed by Steven Pinker in this volume, the principle that dominated enquiry into human nature in the post war years was the ‘blank slate’, the concept that the mind of man (uniquely among animals) was essentially free of biological constraints. Sexual inclination, intelligence, personality and character were all claimed to be the products of culture, rather than biology. The argument was bolstered by the fact that many key aspects of human social behaviour, such as altruism appeared, on the face of it, to be contrary to the predictions of the theory of natural selection. As Darwin himself lamented, it is the struggle (for survival) between individuals that dominates the natural world; but cooperation rather than competition is the cornerstone of all human cultures. The structure of DNA was elucidated in 1953, but despite the realization that genes encoded the form of the brain, its significance for understanding how the human mind worked was generally considered to be minimal.
The blank slate view of a human nature entirely free of the shackles of biology persisted for several decades. But in the latter years of the twentieth century the slate became increasingly marked by the scratchings of neurobiologists, sociobiologists, behavioural psychologists and geneticists. The entomologist E.O. Wilson was amongst the first to pick up the chalk with the publication of Sociobiology: The New Synthesis in 1975. Wilson’s book explored new evolutionary insights (by himself, Robert Trivers, John Maynard-Smith and many other biologists) into the social behaviours of animals, and by extension, humanity. A year later Richard Dawkins published The Selfish Gene in which he provided a genocentric view of the entire realm of biology. Animal social behaviours, such as altruism, now yielded to genocentric theories such as kin selection and reciprocal altruism. If genes could persuade animals like bats to be kind to strangers then it became increasingly difficult to argue that they could not similarly be involved in human altruism.
Alongside advances in theoretical biology came genetic studies that demonstrated inherited components to relatively common behavioural conditions, such as autism or schizophrenia. Gene involvement in mental capacity had already been accepted for genetic diseases such as Down’s syndrome. But Down’s syndrome (which is usually caused by the inheritance of three, rather than two, copies of chromosome twenty-one) was considered an extreme genetic condition with no relevance to the normal population. In contrast, autism and schizophrenia exhibit spectrums of disease that range from the extremely dysfunctional to people who lead relatively normal lives. Genes appeared to be involved all the way along the spectrum implying that genes affected the way apparently normal people thought. Neurobiologists and psychologists entered the fray with the demonstration that lesions in particular regions of the brain caused behavioural disturbances such as aggression, hyperactivity, depression or cognitive defects such as the visual agnosia experienced by the eponymous patient of Oliver Sacks’ book, The Man Who Mistook His Wife For a Hat. Once again, the spectrum of dysfunction overlapped with the range of behaviour found in apparently normal people, suggesting that a good deal of the natural variation in humankind sprang from physical rather than cultural causes.
Yet, despite these advances, academics and critics in the social science or humanities – the traditional home for those interested in the study of humankind – remained either deeply sceptical or openly hostile to any mechanistic account of human nature. The tone was set nearly a century ago by George Bernard Shaw who wrote to Henry James, ‘In the name of human vitality WHERE is the charm in that useless, dispiriting, discouraging fatalism which broke out so horribly in the eighteen-sixties at the word of Darwin, and persuaded people in spite of their own teeth and claws that Man is the will-less slave and victim of his environment? What is the use of writing plays? – what is the use of anything? – if there is not a Will that finally moulds chaos itself into a race of gods with heaven for an environment, and if that Will is not incarnated in man …’ Half a century later, C.P. Snow lamented the continuing divide between the sciences and the humanities in his lecture on The Two Cultures. And, as discussed earlier, though postmodernism has largely discarded Shaw’s ‘Will’ as a component of human nature, it remains equally hostile to biological explanation of the way we are.
The basic tenet of the scientific approach is that there is an objective reality out there for science to uncover. In this view, science occupies a special place amongst human endeavours in that its ‘truths’ should float free of the belief systems of the scientists who establish them: Newton’s laws of gravity should be just as true to an Australian aborigine or an Inuit Indian as they were for an English gentleman. But though a reasonable case can be made for the laws of physics, immutability of the laws of natural world is much less certain. The history of eugenics should perhaps give pause to any geneticist claiming overarching truths; but when in June 2000 Francis Collins announced the near completion of the Human Genome Project at a White House reception, he proclaimed ‘We have caught the first glimpse of our own instruction book, previously known only to God’. This claim for scientific objectivity standing outside of culture was questioned as far back as Karl Marx who wrote to Engels that ‘It is remarkable how Darwin rediscovers, among the beasts and plants, the society of England with its division of labour, competition, opening up of new markets, ‘inventions’ and Malthusian ‘struggle for existence’. In this volume, Catherine Belsey notes a similar match between the functionalist description of human nature and the modern suburban lifestyles of the (mostly male) scientists who promote sociobiology theories. And it can hardly be a coincidence that the debate on the validity of gene-centred theories of human nature has tended to separate scientists into camps that reflect their political views as accurately as their scientific ones. It seems that the political affiliation of scientists is an important influence on their critical assessment of scientific theories.
Postmodernists argue that the language through which science is communicated inevitably leaves a trail of cultural baggage. A gene may have an objective reality but a ‘selfish gene’ is a construct that depends on the culturally loaded meaning of the term ‘selfish’. ‘Gene’ itself means different things to different scientists who vary widely in the degree of genetic control that they are prepared to accept for these entities. So how can any theory of genes be universally true if its truth is conditional on the meaning of its terms? The philosopher Dan Dennett coined the term ‘greedy reductionism’ to describe the habit of some scientists of relentlessly reducing explanations down to the smallest possible level, in this case, genes. Most notoriously, Herrnstein and Murray published The Bell Curve in 1994 arguing that genetic differences in intelligence accounted for most of the economic inequality in American society: if you are poor it’s probably because you are stupid. The Bell Curve was greeted with howls of protests and Herrnstein and Murray were claimed to be ‘academic Nazis’ and closet eugenicists. Many fellow sociobiologists came to be tarred with the same brush and were accused of racism, sexism, and homophobia. Public speaking engagements in the US were often marred by verbal abuse and mass walkouts. More recently, the efforts of the Human Genome Diversity Project (HGDP) to collect DNA from the full range of human variability has been halted in its tracks by suspicions, particularly amongst many native people, that the true intention of the project was a kind of post-colonial genetic exploitation rather than rational science.
So a ‘gene’ may be piece of DNA, a unit of heredity or a tool of exploitation. Its influence could be profound or trivial, depending on your viewpoint. Yet despite the uncertainties over their precise nature, they have continued to be implicated as causes of human nature. With the sequencing of the human genome in the closing years of the 20th century scientists were presented with approximately thirty two thousand genes and as many as half of them were likely to be involved in brain development and function. Few scientists would argue today that all this genetic inheritance has absolutely no role to play in the way our brain works.
A posthuman future?
The arguments rage on with both sides mostly talking past each other. The debate would have only academic interest were it not for the fact that genetic engineering, human cloning and gene therapy are likely to provide the tools that 19th and 20th century eugenicists lacked: the ability to engineer human nature. The coming decades will probably see successful gene therapy developed for lethal genetic diseases, such as cystic fibrosis or muscular dystrophy. But the same tools may be applied to those conditions, such as autism of schizophrenia, where dysfunction flows smoothly into normality and even genius. Should we/could we engineer minds free of schizophrenia or autism at the risk of losing some of the range of human variability that has given us brilliant poets, writers, artists or scientists? What of aggression, which has been similarly linked (though not nearly as convincingly) to genes? Or hyperactivity, or low intelligence, or gender choice? Or what about positive attributes, like intelligence or creativity if these are found to have inherited components? IVF clinics already offer prospective mothers a selection of attributes in their sperm donors. Reproductive clinics of the future may be able to offer extra doses of intelligence or creativity genes to their clients (at a price of course). Nearly all of us want our children to be clever, talented, successful and with tastes and ethics broadly similar to our own, but would we be prepared to load the genetic dice to achieve these aims? What is the prognosis for human nature if it does indeed yield to genetic tinkering?
And what of reason? The scientific age was initiated by the Age of Reason. But as Catherine Belsey asks in this volume, can science, the product of reason, unpick its own cause? And where is Shaw’s ‘Will’ (if it exists) located in all those neurons and genes? Are we slaves to reason, to our genes or to our culture?
Most scientists admit they are not necessarily the best people to answer these questions. The modern scientific mind is generally focused on detail and the particular rather than the broad sweeps required to encompass the range and complexity of human nature. It is surely in the products of the humanities, great literature and the arts, where the quest to understand human nature has reached its highest expression. Yet, as discussed earlier, most of the humanities, and particularly the discipline of literary criticism, remains deeply hostile to any attempt to bring genes into any discussion of human behaviour or culture. And the fact that The Da Vinci Code has outsold all books on the genetic code many times over is a sobering reflection of the position of science in the minds of most readers.
From Human Nature: Fact and Fiction by Robin Headlam-Wells and Johnjoe McFadden published by Bloomsbury, 2006.