Few people would deny that humans are animals, evolved beings with evolved bodies and evolved minds. Equally, few would deny that humans are in some fashion distinct from other animals. In part, at least, the debate about what science can or cannot tell us about human nature is a debate about how we should understand the relationship between continuity and distinctiveness, and about whether we can explain what is distinctive about humans in the same terms as we explain the continuity of humans with the rest of the natural world - in other words, can the distinctive aspects of being human be explained in naturalistic terms? Those are the two questions I want to consider here.
In recent decades there has been a conceptual shift in the way we approach these two questions. There has been an increasing tendency to deny the exceptional character of being human and to view humans as little more than sophisticated animals - in other words to stress the continuities at the expense of the discontinuities. Driving this shift have been both scientific and political arguments. Let me deal with the scientific arguments first; I will return to the political issues later.
For many natural scientists, any acknowledgement of human exceptionalism smacks of mysticism. The primatologist Frans de Waal, for instance, suggests that the traditional distinction between nature and culture is one more expression of 'outdated Western dualism'. Natural selection, he argues, 'has produced our species, including our cultural abilities. Culture is part of human nature'. And since human nature can be understood through 'a combination of neurophysiology and deep genetic history', as EO Wilson has put it, so all that appears distinctive about human beings - language, morality, reason, culture itself - is not in fact that exceptional, and can be understood in the same way as can all natural phenomena.
The naturalistic viewpoint, the biological anthropologist Rob Foley suggests, 'turns every large philosophical and metaphysical question into what are often straightforward and even boring technical ones'. For example, Darwinism turns the question 'Where do humans come from?' into a specific discussion about the time and the place where humans evolved. Similarly, Darwinists deal with the question 'What is unique about humans?' by comparing human anatomy, physiology and behaviour with that of non-human animals. 'Human origins and ultimately human nature', Foley insists, 'are not philosophical questions.'
Yet Foley himself concedes that matters are not so simple. Darwinists cannot simply ignore wider philosophical issues when they consider human evolution. For instance, Foley observes that 'the question "When did we become human?"... may appear a straightforward question about the fossil record.' In practice, however, the answer 'turns out to hinge not just on the technicalities of dating fossils, but on the criteria by which humanity is defined... Is it language, culture, bipedalism, intelligence, tool-making, or any other number of characteristics?' And, as even a cursory glance at the history of debates about human evolution reveals, these criteria are often shaped by wider social influences.
There is, I think, a more profound problem, too. It is not simply that the data of science require an interpretative framework. The very character of natural science, I believe, constrains what it can tell us about what it is to be human.
A paradox of natural science is that its success in understanding nature has created problems for its understanding of human nature. The success of science derives from the way that it has 'disenchanted' the natural world, to borrow Max Weber's phrase. Whereas the prescientific world viewed the universe as full of purpose and desire, the scientific revolution transformed nature into an inert, mindless entity. At the heart of the scientific methodology is its view of nature, and of natural organisms, as machines; not because ants or apes are inanimate, or because they work like watches or TVs, but because, like all machines, they lack self-consciousness and will.
Humans, however, are not disenchanted creatures. We possess - or, at least, we believe we possess - purpose and agency, self-consciousness and will, qualities that science has expunged from the rest of nature. Uniquely among organisms, human beings are both objects of nature and subjects that can, to some extent at least, shape our own fate. We are biological beings, and under the purview of biological and physical laws. But we are also reflexive, rational, social beings, who can design ways of breaking the constraints of biological and physical laws. We are, in other words, both immanent in nature and, in a certain manner, transcendent to it.
The very development of the scientific method has exacerbated this paradox of being human. To study nature scientifically requires us to make a distinction between a humanity that is a thinking subject and a nature that presents itself to thought but is itself incapable of thought. When studying 'external' nature the distinction between the thinking subject and the object of study is easy to make. But with the study of humans, such a neat division becomes impossible: human beings are simultaneously the subject that thinks and the object of that thought. We can understand humans as beings within nature that can be studied by science. But the very act of studying humans in this fashion takes them in a certain sense outside of nature because of the distinction we must make between an objective nature and a thinking humanity.
This is, in Kate Soper's words, 'the paradox of humanity's simultaneous immanence and transcendence'. Nature 'is that which Humanity finds itself within, and to which in some sense it belongs, and also that from which it seems excluded in the very moment it reflects upon either its otherness or its belongingness'.
Our very capacity to reflect upon nature, then, takes us in some sense outside of nature, for if we could not view nature from the outside we could not reflect upon it objectively.
Humans, in other words, have a 'dual character', as both object and subject. And this dual character necessarily shapes the debate about continuities and discontinuities between the human and non-human world. Over the centuries many thinkers have pointed to some specific quality - culture, reason, tool-use, language, morality - as that which makes humans distinct. Others, especially in the wake of Darwin, have argued that each of these qualities can also be found in non-human animals: that many animals use tools, act according to reason, have the capacity for language, act morally and possess culture.
I don't want to enter this debate. But I do want to suggest that the meaning of all these qualities is different for humans than it is for non-humans, because only humans exist as subjects. For humans, such phenomena cannot be understood simply from a naturalistic viewpoint.
Take for instance culture. Frans de Waal defines culture as 'knowledge and habits [that] are acquired from others'. It explains why 'two groups of the same species may behave differently'. Under this - very reasonable - definition many species of animals can be viewed as cultured.
Humans, however, do not simply acquire habits from others. We also constantly innovate, transforming ourselves, individually and collectively, in the process. There is a fundamental difference between a process by which certain chimpanzees have learnt to crack open palm-nuts using two stones as 'hammer' and ‘anvil’, and a process through which humans have engineered the industrial revolution, unravelled the secrets of their own genome and developed the concept of universal rights.
Many animals may well be cultural creatures under a naturalistic definition. But humans are entirely different sorts of cultural beings. In the seven million years or so since the evolutionary lines of humans and chimpanzees first diverged on either side of Africa's Great Rift Valley, chimpanzees have evolved, but, in comparative terms, their behaviour and lifestyles have barely changed. Human behaviour and lifestyles have clearly transformed out of all recognition. Humans have learnt to learn from previous generations, to improve upon their work, and to establish a momentum to human life and culture that has taken us from cave art to quantum physics. All animals have an evolutionary past. Only humans make history.
Science has expunged consciousness and teleology from the natural world. But consciousness and teleology remain crucial aspects of the human world. Any naturalistic account of humanness, therefore, has to account for human consciousness and teleology in non-teleological terms.
One approach has been to argue that consciousness and teleology are illusions, phenomena that natural selection has designed us to believe in, not because they are true, but because they are useful. As the neuroscientist Colin Blakemore has put it, when 'we feel ourselves to be in control of an action, that feeling itself is the product of our brain, whose machinery has been designed, on the basis of its functional utility, by means of natural selection'. According to Blakemore, 'To choose a spouse, a job, a religious creed - or even to choose to rob a bank - is the peak of a causal chain that runs back to the origin of life and down to the nature of atoms and molecules.'
We think we are in charge, but in reality there is no self that can take charge. There is simply the machinery of the brain churning away, thanks to a chain of causal links that goes back to the Big Bang itself.
A variation on this argument is provided by the psychologist Susan Blackmore who adopts Richard Dawkins' notion of a meme, a unit of culture that inhabits, or rather parasitises, our brains. Blackmore suggests that 'Instead of thinking of our ideas as our own creations, and working for us, we have to think of them as autonomous selfish memes, working only to get themselves copied.' Since 'we cannot find either beliefs or the self that believes' by looking into somebody's head, she argues, so we must conclude that there are no such things as beliefs or selves, 'only a person arguing, a brain processing the information, memes being copied or not'. In such naturalistic arguments not just Cartesian dualism but the Cartesian subject - the active, conscious agent of human action whom Descartes introduced into modern philosophy - has disappeared.
The problem with arguments such as these is that, by their own criteria, they provide us with no reason for believing in them. From an evolutionary point of view, truth is contingent. Darwinian processes are driven by the need, not to ascertain truth, but to survive and reproduce. Of course, survival often requires organisms to have correct facts about the world. A zebra that believed that lions were friendly, or a chimpanzee that enjoyed the stench of rotting food, would not survive for long. But although natural selection often ensures that an organism possesses the correct facts, it does not always do so. Indeed, the argument that consciousness and agency are illusions designed by natural selection relies on the idea that evolution can select for untruths about the world because such untruths aid survival.
If, then, our cognitive capacities were simply evolved dispositions, there would be no way of knowing which of these capacities lead to true beliefs and which to false ones. Even defenders of the naturalistic hypothesis recognise this problem. The late Robert Nozick, for instance, suggested that 'Reason tells us about reality because reality shapes reason, selecting for seems "evident".' But, he acknowledged, if this is the case, then the evolutionary explanation of reason itself may be suspect:
The evolutionary explanation itself is something we arrive at, in part by the use of reason to support evolutionary theory in general and also this particular application of it. Hence it does not provide a reason-independent justification of reason, and although it grounds reason in facts independent of reason, this grounding is not accepted by us independently of reason.
Evolutionary theory provides an explanation of, but not a justification for, reason. Although it grounds reason in certain evolutionary facts, this is causal grounding only. These facts are not supposed to provide us with grounds for accepting the validity or reliability of reason. But, as Thomas Nagel observes, without a justification for reason, we have no basis on which to accept the evolutionary hypothesis as an explanation for it:
Unless it is coupled with an independent basis for confidence in reason, the evolutionary hypothesis is threatening rather than reassuring... I have to be able to believe that the evolutionary explanation is consistent with the proposition that I follow the rules of logic because they are correct - not merely because I am biologically programmed to do so. But to believe that, I have to be justified independently in believing that they are correct. And this cannot be merely on the basis of my contingent psychological disposition, together with the hypothesis that it is the product of natural selection.
What this means, Nagel point out, is that 'the evolutionary hypothesis is acceptable only if reason does not need its support... One cannot embed all one's reasoning in a psychological theory, including the reasonings that have led to that psychological theory.' The epistemological buck, as Nagel puts it, must stop somewhere.
The logic of the kind of argument put forward by Colin Blakemore, in other words, undermines our confidence in its own veracity. For, if we are simply sophisticated animals or machines, then we cannot have any confidence in the claim that we are only sophisticated animals or machines. We are only able to do science because we possess the capacity to transcend our evolutionary heritage, because we exist as subjects, rather than simply as objects.
For this and many other reasons, many find implausible the notion that human agency is just an illusion. They therefore adopt a different approach – accepting, in principle, the existence of self-consciousness and agency, but ignoring them in practice when formulating scientific concepts of human nature.
The psychologist Steven Pinker, for instance, points out that moral reasoning depends upon our acknowledgement of ourselves as sentient beings. By sentience Pinker appears to mean our existence as moral beings with self-consciousness and agency. The concept of sentience, Pinker observes, 'underlies our certainty that torture is wrong and that disabling a robot is the destruction of property but disabling a person is murder'. Pinker acknowledges that, as yet, we have no idea how to explain sentience scientifically. But, he argues, 'Our incomprehension of sentience does not impede our understanding of how our mind works.'1
It seems odd to hold that sentience is both central to human thinking and also irrelevant to our understanding of how the mind works. As the neurologist Raymond Tallis points out, to construct a theory of the human mind while ignoring self-consciousness is a bit like 'trying to build a house by starting at the second floor'.
Self-consciousness, Tallis observes, 'is the first, not the last, problem... of psychology. It is not merely the most difficult of the problems of consciousness or mind; it is also the pivotal one and addressing it cannot be postponed until one has solved the "easier" problems such as those pertaining to "cognitive functions" like intelligence, memory, thinking etc.' Consciousness and agency, in other words, are not phenomena tacked onto human nature; they are at the heart of what it is to be human.
The relationship between humans as physically determined beings, and humans as conscious agents - between humans as objects and humans as subjects - is clearly one of the most difficult problems for scientists and philosophers. While analytically we can talk of humans either as subjects or as objects, in reality humans are simultaneously both subject and object. We have at present no conceptual framework within which to consider such an ontological peculiarity. But denying one or other aspects of our humanness is not a way of solving the conundrum. Those who insist that humans can be understood in purely naturalistic terms are in practice forced to give up on the attempt to understand humans as subjective beings, and compelled to view us simply as objects.
Another way of putting this is that human nature is not simply natural. We often lose sight of this because of the ambiguity of the concept of human nature. On the one hand, human nature means that which expresses the essence of being human, what Darwinists call 'species-typical' behaviour. On the other, it means that which is constituted by nature; in Darwinian terms, that which is the product of natural selection.
In non-human animals the two meanings are synonymous. What dogs and bats or sharks typically do as a species, they do because of natural selection. But this is not true of humans. The human essence - what we consider to be the common properties of our humanity - is shaped as much by our history as by our biology.
The historicity of the human essence is revealed in a number of different ways. One lies in the way that universal social forms are often the product of social and historical, not biological, development. The fact that humans are rational, social beings places certain constraints and creates certain opportunities that can shape the way we think about the world and organise our collective lives. Being rational we are able to apprehend the regularities of the objective world and to draw conclusions from them. Being social creates certain opportunities common to all societies - the possibility of a division of labour, for instance - and imposes certain universal restrictions - such as the need for social order. Being both social and rational means that the common social goals, opportunities and constraints are often tackled in a similar fashion in different societies.
In 1945 the anthropologist George Murdoch set out a group of items which he believed occurred in 'every culture known to history or ethnography'. More recently Donald Brown has updated this with considerably more comprehensive list. These list of universals have become celebrated and are often cited by sociobiologists and evolutionary psychologists making the case for the evolved character of human psychology. What is striking about these lists, however, is how many of these universals can be understood in social or cultural terms, rather than necessarily as evolved adaptations.
The apparent universal classification of weather conditions, for instance, relies on objective regularities in the world, the capacity of humans to apprehend such regularities and the social need for humans to understand such regularities. Creation of regimes of cleanliness is crucial given that humans live in communities, fear the spread of disease and have the rational capacity to design ways of avoiding this. The practice of using personal names becomes important in a species in which individuals not only have distinct characters but distinct duties and responsibilities for which they can be held to account. And so on. In each case, the criteria for the development of these traits are social needs and opportunities that are universal. In other words, the universal existence of these needs and opportunities within human communities means that it is quite possible for every human culture to have developed such traits (or to have appropriated them from other cultures) without these having been designed by natural selection.
A second expression of the historicity of the human essence lies in the way that human nature is often normative. Salman Rushdie has suggested that if human nature did not exist, then 'the idea of universals - human rights, moral principles, international law - would have no legitimacy.' This idea has become central to the contemporary science of human nature. A number of evolutionary psychologists have suggested, for instance, that revulsion at the practice of slavery is part of human nature because we have a natural aversion to being humiliated and imprisoned. Francis Fukuyama has taken this argument to show that liberal capitalism lies at the end of history because its beliefs and institutions 'are grounded in assumptions about human nature that are far more realistic than those of their competitors'.
For most of human history, though, slavery was regarded as natural as individual freedom is today. Only in the past two hundred years have we begun to view the practice with revulsion. We have done so partly because of the political ideas generated by the Enlightenment, partly because of the changing economic needs of capitalism, and partly because of the social struggles of the enslaved and the oppressed. Certainly, today we view opposition to slavery as an essential aspect of our humanity, and see those who advocate slavery as in some way inhuman - but it's a belief that we have arrived at historically, not naturally. To understand human values such as the belief in equality we need to explore not so much human psychology as human history.
A final illustration of the historicity of the human essence lies, paradoxically, in the universality of great art. Many thinkers from George Steiner to EO Wilson have suggest that great artists such as Dante, Shakespeare or Beethoven are appreciated across cultures and over time because their work taps into the universal features of human nature. In his book, The Blank Slate, Steven Pinker argues that art is 'in our genes', because nature endows us with an innate aesthetic sense. Hence Shakespeare is appreciated in 21st century Japan as much as it was in 17th century England. Modernism, on the other hand, has been an aesthetic failure, Pinker suggests, because it developed out of what Pinker calls the 'militant denial of human nature'.
This is no place to enter here into a discussion about the merits - or otherwise - of Pinker's understanding of modernism. But I do want to suggest that his is a misunderstanding of Shakespeare's genius. Shakespeare did not simply articulate universal themes of love, lust and power; he also helped fashion a new vision of what it is to be human. Shakespeare's characters speak to us in an entirely different way because, unlike previous literary figures, they possess a self-consciousness as we possess self-consciousness. As the American critic Harold Bloom puts it, 'Insofar as we ourselves value, and deplore, our own personalities, we are the heirs of Falstaff and Hamlet, and of all the persons who throng Shakespeare's theater of what might be called the colors of the spirit'.
Shakespeare was not alone in developing a new language through which to understand our emotions and feelings. The kind of sensibility that Shakespeare brought to the stage, his near-contemporaries Rembrandt and Vermeer worked into a canvas. Rembrandt is regarded as the first, perhaps the greatest, of all self-portraitist because when we view his paintings we come face to face, for the first time in history, with a person, a self. It is impossible to look at his self-portraits, especially of old age, and not see Rembrandt himself. In a similar way, Vermeer's paintings reveals the new eyes through which painters now viewed their subjects as persons.
What we are witnessing in Shakespeare, Rembrandt, Vermeer, and countless others, are the beginnings of the modern idea of subjectivity, of the individual as a rational agent, and of the marking out of the private sphere as we conceive of it today. It was in this period that the idea of the 'inner man' began to take shape, an idea that, most importantly, was given philosophical shape through Descartes' concept of the thinking subject. When Descartes suggested that cogito ergo sum he helped create the idea of 'I' in a modern sense.
The motor for these changes in self-conception lay in particular social and economic developments in early modern Europe - the spread of market relations, the creation of a merchant class, the belief that wealth and privilege was the product of an individual's activities, not simply a divine gift or the result of one's social status. The consequences was to establish a notion of self and of personality that today we take to be natural because we cannot imagine any other way of thinking about such concepts.
Human emotions are the product of our evolutionary heritage. But the self that possesses those emotions has been forged in the furnace of history. That is why Shakespeare's work is paradoxically both universal and contingent. It is universal because today, whether we live in Britain or in Japan, we are able to recognise in his characters the workings of our own self. It is contingent because this concept of the self was not given by nature but made in history.
Human nature, then, cannot simply be understood as a natural phenomenon because it is also historically constituted. And this historicity of human nature establishes limits to naturalistic explanations of what it is to be human.
Someone might say, 'Hold on, does not a scientific view of the world require a naturalistic philosophy? In questioning naturalism, are we not in danger of invoking supernatural or divine explanations of how the world operates, opening the way to, say, Creationism and the like?'
The answer to this depends upon the definition of naturalism, or rather upon the redefinition that has taken place in recent decades. Originally, as the concept developed through the seventeenth and eighteenth centuries, 'naturalism' meant the ability to explain all events and phenomena without recourse to the supernatural and the divine. It came to be understood as a liberation from the dogmas of religion and the conservative social order for which they served as an ideology, as well as a declaration of independence for scientific inquiry into both the nature of the world and human nature. In this sense I consider myself a naturalist.
In recent decades, though, there has been redefinition of naturalism which is now widely taken to mean not simply the rejection of supernatural accounts but also the acceptance of the idea that the explanations of natural science suffice to explain all phenomena, not just the phenomena of nature; in other words that mental and social phenomena can be reduced to the physical. Naturalism has been reformulated as an all-embracing physicalism. For a contemporary naturalist the only conceptual system in terms of which the world and its processes can be reliably characterised is that of the physical sciences of nature. In contemporary naturalism, as Frederick Olafson has put it, 'The world and nature are one and the same, and everything in them is of the same ontological type.'
Thus EO Wilson suggests that 'sociology and other social sciences, as well as the humanities, are the last branches of biology'. And Richard Dawkins believes that 'Science is the only way to understand the real world.' It's a view, I believe, that confuses the physical world with the 'real' world. For, as Mary Midgley has pointed out, 'Toothache is as real as teeth' and 'debt is as real as the house that was bought with it.' The social and the mental are as real as the natural. But the social and the mental cannot be understood as if they were simply natural.
The irony of such naturalism is that, while its starting point is a rejection of Cartesian dualism, its inability to make sense of agency leads it back into the Cartesian swamp. 'We are built as gene machines', Richard Dawkins wrote in The Selfish Gene, but we also possess 'the power to turn against our creators.' And according to Steven Pinker he is 'by Darwinian standards... a horrible mistake'. Why? Because he has chosen to remain childless. 'I am happy to be that way', he adds, 'and if my genes don't like it they can go and jump in the lake.' For thinkers like Dawkins and Pinker, human values and human nature are not rooted in nature but are non-natural creations.
But if we are built as gene machines how do we possess the power 'to turn against our creators', or to tell our genes to 'go jump in the lake'? Presumably such a capacity must itself be an evolved trait. But how could such a trait, which by definition reduces biological fitness to zero, survive? If a horse or a chimp told its genes to go take a jump, it would not survive very long in evolutionary terms. So how is it possible for humans to act like this, if we are simply natural creatures?
Moreover, human values, presumably, do not float down from the sky, but emerge out of human thought and behaviour. How then do they originate if not through 'natural selection and neurophysiology' which Pinker and Dawkins hold to be the basis of all other behaviours? Pinker explains it like this:
The mechanistic stance allows us to understand what makes us tick and how we fit into the physical universe. When those discussions wind down for the day, we go back to talking about each other as free and dignified human beings.
But freedom and dignity seem here to have no relationship to the physical world, and hence to human nature. They seem to float free in a universe of their own. We have jumped headlong, in other words, back into the Cartesian swamp where the physical is unconnected to the moral world. As Frans de Waal has said of such arguments, 'These authors want to have it both ways: human behaviour is an evolutionary product except when it is hard to explain.'
De Waal's own solution is to see morality as natural, in the same way as is culture. The trouble with this argument, however, is the same as with culture: it ignores the dual character of being human. Morality in human life is based on our existence as subjects - that is, as moral agents capable of taking responsibility for our actions and who, through history, can develop our moral sensibilities. What we might call morality in the non-human world describes behaviours by beings that are objects - beings that do not possess agency, cannot take responsibility, and for whom the notion of moral progress is inapplicable. Once you fail to make such a distinction then you are forced to accept, as Colin Blakemore does, that 'moral responsibility has no real meaning but it's a fiction we've created because otherwise society could not work.' If, on the other hand, one believes that moral responsibility and political agency are more than fictions, then one has to take seriously the existence of humans as subjects.
What all this reveals is that the tension between scientific naturalism and human exceptionalism remains unresolved. It seems crucial to think of humans as conscious agents capable of rational thought and collective action if science itself is to advance. Yet humanism appears to be an obstacle to the realisation of a fully materialist science of Man. By making humans into conscious agents we seem to separate them from the rest of nature, and hence suggest that the language of natural science cannot fully encompass our humanness.
How this tension plays itself out at any particular moment depends not just on the arguments of science, but also on wider cultural views of Man. What underlies contemporary naturalism - the stress on human continuities with the natural world at the expense of the discontinuities - are not simply scientific developments (though there have been tremendous advances in recent years in evolutionary biology, genetics, neuroscience, psychology, artificial intelligence, etc) but also the cultural pessimism that infects our age. We live in an age that is deeply pessimistic about the human condition. A century of unparalleled bloodshed and destruction has created a widespread skepticism about human capacities.
Every impression that humans make upon the world seems for the worse. The attempt to master nature appears to have led to global warming and species depletion. The attempt to master society, many feel, led directly to Auschwitz and the gulags. We no longer believe, as Michael Ignatieff has observed, that 'material progress entails or enables moral progress'. We eat well, we drink well, we live well 'but we do not have good dreams'. The Holocaust 'remains a ghost at our feast'. The result has been a growth of anti-humanism, of despair about human capacities, a view of human reason and agency as forces for destruction rather than for betterment.
Half a millennia ago, Descartes viewed reason as 'the noblest thing we can have because it makes us in a certain way equal to God and exempts us from beings his subject'. Today, many view human reason as a tool for destruction rather than betterment. 'Progress and mass murder run in tandem', John Gray writes in his provocative new book, Straw Dogs. 'As hope for a better world has grown, so has mass murder.' Gray, Professor of Modern European Thought at the London School of Economics, rejects the idea that human consciousness and agency have any value, or indeed are any more than absurd illusions. 'The freest human being', he suggests, 'is not one who acts on reasons he has chosen for himself, but one who never has to choose. Such a human being has the perfect freedom of a wild animal - or a machine.' 'In a real sense', the late ecologist Murray Bookchin noted, 'we seem to be afraid of ourselves - of our uniquely human attributes. We seem to be suffering from a decline in human self-confidence and in our ability to create ethically meaningful lives that enrich humanity and the non-human world.'
As we have become more pessimistic about the human condition, as the exceptional status of human beings has seemed at best mere self-delusion, at worst dangerously hubristic, so the idea that humans are just beasts (literally and metaphorically) has appeared both scientifically plausible and culturally acceptable.
The history of the twentieth century, the biological anthropologist Rob Foley argues, has transformed scientists' vision of humanity, leading to 'a loss of confidence in the extent to which humans could be said to be on a pedestal above the swamp of animal brutishness':
The camps of Dachau and Belsen, the millions killed in religious wars, the extent of poverty, famine and disease, and the almost boundless capacity of humans to do damage to each other at national and personal levels have, in the twentieth century, rather dented human self-esteem.
The Victorians believed that humans were closer to the angels than to the apes. During the course of the twentieth century, however, Foley notes, 'apes have become more angelic' while humans have become 'more apish'. 'Where it was originally thought that humans were the advanced and progressive form of life and other animals the more primitive', he concludes, 'now it may be argued that the animal within us is our noble side, and humanity or civilisation the blacker side - a complete reversal of the original Victorian image'.
The pessimism of contemporary culture, in other words, has cleared a space for a more naturalistic vision of humanity, a vision that seeks to erase the distinctions between humanity and nature and to deny the exceptional qualities of being human.
This retreat from humanism, and the rejection of human exceptionalism, makes, I believe, for both bad science and bad politics. It makes for bad science because the attempt to understand humans in the same language as the rest of nature ignores an essential quality of humanness - human agency. And it makes for bad politics because once we accept that human agency - and human reason - are forces for destruction rather than betterment, then we lose the only means we possess for human advancement, whether social, moral or technological.
The tension between scientific naturalism and human exceptionalism is not an embarrassment that needs to be swept away, but an important way of understanding what it is to be human. We will, I believe, develop in time a conceptual framework that allows us to mediate the two. In the meantime, we should recognise the tension as a reflection of the dual character of being human, as beings both in and out of nature, as both objects and as subjects.