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of 'outdated Western dualism'.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'.1
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.'2
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?'3
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'.4
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'.5
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.'6
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'.7
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.8
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 points out, 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.9
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.'10
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.'11
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.