As humanists we tend to be materialists, rejecting divine or mystical explanations for any natural or human phenomena. And as materialists we tend to believe that we can understand human beings, and the human mind, in the same way as we understand any other phenomena in nature. From such a naturalistic viewpoint the human mind is simply a sophisticated version of the animal mind, or a sophisticated version of a machine.

I want to argue that this is an entirely muddle-headed way of understanding human beings and the human mind. Indeed I want to argue the very opposite: first, that human beings are exceptional beings, not simply unique in the sense that every species is unique, but exceptional in that humans cannot be understood solely as natural beings. The rejection of human exceptionalism is not a materialist, but a mechanistic outlook. And second, I want to show that such mechanistic views have become fashionable, not because of advances in science, but because of the growth of antihumanist sentiments in our culture.

A paradox of 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 animals are inanimate, nor because ants or apes work like computers or TVs, but because, like all machines, they lack agency and will. Animals are objects of natural forces, not potential subjects of their own destiny. They act out a drama, not create one.

Humans, however, are not disenchanted creatures. We possess purpose and agency, 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 to some extent can shape our own fate. We are biological beings, and under the purview of biological and physical laws. But we are also conscious beings with purpose and agency, traits the possession of which allow us to design ways of breaking the constraints of biological and physical laws. We are, in other words, both inside nature and outside of it.

Transcendence

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 outside of nature because of the distinction we must make between inert, mechanical nature and active, thinking humanity. This is, in philosopher 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."

To talk of humans as 'transcendent' is not to ascribe to them spiritual properties. It is, rather, to recognise that as subjects we have the ability to transform our selves, our natures, our world, an ability denied to any other physical being. In the six million years since the human and chimpanzee lines first diverged on either side of Africa's Great Rift Valley, the behaviour and lifestyles of chimpanzees have barely changed. Human behaviour and lifestyles clearly have. 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 and the conquest of space. It is this capacity for constant innovation that distinguishes humans from all other animals. All animals have an evolutionary past. Only humans make history.

All non-human animals are constrained by the tools that nature has bequeathed them through natural selection. They are not capable of striving towards truth; they simply absorb information, and behave in ways useful for their survival. The kinds of knowledge they require of the world have been largely pre-selected by evolution. No animal is capable of asking questions or generating problems that are irrelevant to its immediate circumstances or its evolutionarily-designed needs. When a beaver builds a dam, it doesn't ask itself why it does so, or whether there is a better way of doing it. When a swallow flies south, it doesn't wonder why it is hotter in Africa or what would happen if it flew still further south.

Humans do ask themselves these and many other kinds of questions, questions that have no relevance, indeed make little sense, in the context of evolved needs and goals. What marks out humans is our capacity to go beyond our naturally-defined goals  such as the need to find food, shelter or a mate  and to establish human-created goals.

Some contemporary thinkers believe that there are indeed certain questions that humans are incapable of answering because of our evolved nature. Steven Pinker, for instance, argues that "Our minds evolved by natural selection to solve problems that were life-and-death matters to our ancestors, not to commune with correctness or to answer any question we are capable of asking. We cannot hold ten thousand words in our short-term memory. We cannot see ultra-violet light. We cannot mentally rotate an object in the fourth dimension. And perhaps we cannot solve conundrums like free will and sentience."

Whether or not this is true remains to be seen. What we do know, however, is that most scientific problems  from the structure of DNA, to the physical composition of the sun, to the mechanism of evolution  are problems that would not have been "life-and-death matters to our ancestors". We have solved them despite our evolutionary legacy, not just because of it. The development of science requires mental skills, many of which are evolved adaptations. But it also requires us to transcend those adaptations. Our evolutionary heritage certainly shapes the way that humans approach the world. But it does not limit it, as it does for all other animals.

All humans view the world from a specific perspective: from the perspective of our individual senses, of our particular species, of our particular culture, of the historical period we inhabit. But we are also able to proceed beyond the particularities of our individual lives, to take a more inclusive, objective view of the world. To acquire such an understanding, we need, in the words of the American philosopher Thomas Nagel, "to step back from our initial view of it and form a new conception which had that view and its relation to the world as its object".

To go beyond a purely personal view of the world, we need to climb out of our individual minds, as it were, and view the world from a more external viewpoint. To go beyond the view afforded by a particular culture, we need, metaphorically at least, to climb out of that culture and view it from the outside. And so on. This process of climbing out of immediate circumstances to achieve a more inclusive view is precisely the process of transcendence. Without such a process neither history nor science would be possible.

Uniquely among organisms, then, human beings are both objects of nature and subjects that can, to some degree at least, shape our own fate. Science has expunged teleology from the natural world. But teleology remains a crucial aspect of the human world. The challenge for any mechanistic theory, then, is to explain the teleology of the human world in non-teleological terms.

Mechanism

Mechanistic scientists have risen to this challenge in two ways. One is to deny teleology. The other is to ignore it. Some mechanists argue that teleology is an illusion, something that natural selection has designed us to believe in, not because it is true, but because it is 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". An extreme version of this argument is provided by 'eliminative materialists' such as the philosophers Paul and Patricia Churchland who argue that there are no such as things as desires, beliefs, and minds. These, they believe, are simply figments of a 'folk psychology' that will eventually be swept away by a proper science. (Though, of course, they believe no such thing as, in their universe, beliefs do not exist).

Many find implausible the notion that human agency is an illusion and the self just a story. They therefore adopt a different approach  accepting, in principle, the existence of consciousness and free will, but ignoring them in practice when formulating scientific concepts of human nature. Steven Pinker, for instance, is "as certain that I am sentient as I am certain of anything". Moral reasoning, he points out, depends upon our acknowledgement of ourselves as sentient beings. The concept of sentience "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 at least."

It seems bizarre to hold that sentience is both central to human thinking and also irrelevant to our understanding of how the mind works. As neuroscientist Ray Tallis points out, to construct a theory of the human mind while ignoring sentience is a bit like "trying to build a house by starting at the second floor". Sentience, 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."

The relationship between humans as physically determined beings, and humans as moral agents, is one of the most difficult problems for scientists and philosophers. But denying one or other aspects of our humanness is not a way of solving the conundrum. By insisting that humans can be understood in purely naturalistic terms, mechanistic thinkers are in practice forced to give up on the attempt to understand humans as subjective beings, and compelled to view us simply as objects.

Certainly, recent advances in evolutionary biology, developmental psychology, neuroscience and genetics have helped transform our understanding of human nature, undermining, for instance, the idea of newborn infants as blank slates and providing new insights into everything from autism to sexual behaviour. And it is not surprising that they have  we are, after all, physical beings and evolved creatures.

But so long as researchers treat humans as if we were simply objects, and not as subjects, then they will face a major conceptual obstacle in their understanding of what it is to be human.

Subjectivity

Subjectivity is an integral part of our world. But acknowledging humans as subjects is not the same as saying that humans are beyond understanding. There is no reason why we should not build a rational, scientific account of human subjectivity. What we cannot do, however, is understand it by using solely the same methods that we use to understand purely objective phenomena: the methods of natural science.

Those who continue to insist that we must understand mental states with the tools of natural science because these tools are the best at dismantling the secrets of nature are a bit like the drunk who loses his keys in the gutter, but searches for them under the lamp-post fifty yards up the road because 'that's where the light is'.

Materialism

Many materialists find this argument troublesome because they hold steadfastly to the belief that there is only one way of understanding the world. Materialism, according to the mathematician Norman Levitt, "refers to the view that there is essentially only one kind of reality, one kind of material existence, governed by its unique and invariable set of laws".

There is, however, more than one way to understand 'materialism'. One definition is that the only stuff that exists is physical matter. A second is that one can explain all events and phenomena without recourse to the supernatural or the divine. Materialism can also refer to the belief that the explanations of natural science suffice to explain all phenomena, not simply the phenomena of nature; in other words that mental and social phenomena can be 'reduced' to physical phenomena. This is the sense in which naturalistically-inclined thinkers understand 'materialism'. And it is what I call a 'mechanistic', rather than a materialist, view of the world.

It is quite possible to be a materialist  in the sense of rejecting divine explanations and accepting that the only stuff that exists is physical  without believing that mental and social phenomena can be explained in purely physical or mechanistic terms. A materialist view, in this sense, understands human beings without resort to mystical explanations. But it also sees humans as exceptional because humans, unlike any other beings, possess consciousness and agency. And understanding human consciousness and agency requires us to understand humans as not just natural, but also historical and social beings.

Mechanism and post-modernism

A mechanistic view, on the other hand, sees human beings largely as objects through which nature acts. Few scientists, even those with a mechanistic worldview, would deny that human beings possess consciousness or free will. Yet their desire for a purely naturalistic explanation of the world denies them the resources that allow them to understand humans as subjects. The peculiar place that humans occupy in the natural order means that we require special intellectual tools to understand ourselves. The tools of natural science have been developed for the understanding of objects (animals included), entities without consciousness or subjectivity. They are insufficient to understand what it is to be a human subject.

One of the ironies of a mechanistic view is that its reluctance to acknowledge the human subject has clear parallels with postmodern views of what it is to be human. Most mechanists are clearly, and quite rightly, implacably hostile to postmodernism, and its deconstruction of reason. "There is", as Norman Levitt puts it, "something medieval about it." Postmodernism "seems to represent a rejection of the strongest heritage of the Enlightenment. It seems to mock the idea that, on the whole, a civilisation is capable of progressing from ignorance to insight."

But despite such hostility, what links mechanism and postmodernism is the common distrust of human subjectivity. For mechanists, consciousness and the self are either illusory phenomena, or ones that can be ignored while we go about the scientific business of understanding humans in a purely naturalistic fashion.

Postmodernists equally decry the human subject. For postmodernists, the human subject is not a physical illusion but a historical construction, a myth foisted by European rationalist culture as part of its attempt to colonise the rest of the world, not just physically but also intellectually. Concepts of the subject, the historian Robert Young has written, "mask over the assimilation of the human with European values".

What also links mechanism and postmodernism is that they are both responses to the pessimism that fogs contemporary culture. A century of unparalleled bloodshed and destruction has created a widespread scepticism about human capacities. Every impression that Man makes upon his world, many feel, seems for the worse. The attempt to master nature has led to global warming and species depletion. The attempt to master society has led to Auschwitz and the gulags. We no longer believe, Michael Ignatieff recently observed, that "material progress entails or enables moral progress". We eat well, we drink well, we live well, Ignatieff observed, "but we do not have good dreams". The Holocaust "remains a ghost at our feast".

Natural scientists and social scientists have tended to respond to this pessimism in different ways. Many social scientists have come to deny the very notion of social progress and to question whether humans, just because they possess reason and engage in science, have privileged access to reality. Philosophers like Richard Rorty, for instance, argue that we can never know 'reality'; that the attempt to distinguish between appearance and reality is a chimera; that truth is relative to particular cultures and ages; and that progress cannot be measured in relation to any external yardstick.

Mechanistic thinkers find such views highly objectionable. But mechanism itself is a product of contemporary pessimism. The history of the twentieth century, the evolutionary biologist Rob Foley argues, has transformed scientists' vision of humanity, denting "human self-esteem" and 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 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."

For mechanists, pessimism about human nature has led to the view of humans as just as another animal, and of the human mind as a machine: Man, as Beast and Zombie. Both mechanists and postmodernists deny in their different ways the notion of the exceptional character of human beings. 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 animals or machines has appeared both scientifically plausible and culturally acceptable.

Rationality and subjectivity. In both science and politics they are often seen as conflicting elements. In fact they are integral aspects of our humanity. Together they shape our humanness, and our capacity for both scientific knowledge and political conduct. And together they help define the exceptional nature of human beings. If we ignore one or the other, in either science or in politics, we ignore an essential thread of our humanness.

Kenan Malik is a neurobiologist and psychologist, whose book Man, Beast and Zombie explores these themes.