The image of science which used to
dominate popular and philosophical discussions was very much drawn from
physics. Science was a reductive enterprise: it explained the phenomena which
we observe in terms of the law-governed behavior of tiny particles. On the
basis of this view of science, philosophers sought to elaborate a single set of
criteria which would demarcate science from non-science. Not surprisingly, they
ended up with a very narrow view of science, neatly summed up in Ernst
Rutherford’s claim that "all of nature is physics; everything else is
stamp collecting".

Today, however, much of the most interesting work in
science and in philosophy of science is in biology. The image of science has
changed accordingly; the criteria which a discipline has to meet to count as a
science have been broadened, or the search for such criteria abandoned
altogether. John Dupré has been one of the philosophers in the forefront of
this rethinking of science. He has helped us to rethink what science is, in the
light of biology and of evolution. More recently, however, he has turned from
defending the biological sciences from those who would disparage them, to
attacking them. Or, more precisely, to attacking one way in which these
sciences are understood. He is carrying the fight against reductionism into
biology itself. This book is the latest product of that fight.

Dupré’s main target is the form of reductionism
which consists in dividing up the organism into discrete functional units.
Evolutionary theorists commonly attempt to explain the function of this or that
trait in terms of its contribution to the fitness of the individual. Most
notoriously, and from Dupré’s perspective perniciously, evolutionary
psychologists attempt to divide the mind up into discrete modules, dedicated to
carrying out fitness-relevant tasks: detecting cheaters in social situations,
or assessing the attractiveness of a potential partner in terms of the
probability that mating with them would contribute to one’s reproductive
success. The problems with the latter approach have been analyzed many times,
recently by Dupré himself in his Human Nature and the Limits of Science.
Here he extends the critique beyond psychological structures. He argues that
assigning functions to any phenotypical trait is always much harder than
evolutionary biologists tend to assume. All traits have many fitness effects,
both positive and negative. But when we assess their functions, we necessarily
focus on just some of those effects. Moreover, there is no non-arbitrary manner
in which to identify particular traits. It is only in the context of a whole
organism that any part of it is fitness relevant.

So what can evolution tell us about
ourselves, if it cannot tell us about our bodies and our minds? More or less
nothing, Dupré claims. It is ‘a body of science with almost entirely
intellectual benefits’ (28). The one exception, he claims, is negative: by
undermining its last intellectual support, the theory of evolution delivers ‘a death
blow to pre-scientific, theocentric cosmologies’ (41). In other words,
Christian fundamentalists, on the one hand, and proselytizers for atheism like
Richard Dawkins, on the other, are right: the theory of evolution is
incompatible with religious belief. Since evolution is true, we ought to
abandon religion.

Dupré is certainly right that with
this last piece of the naturalistic jigsaw in place, God plays no explanatory
role in our understanding of the universe, and for that reason believers are
unable to offer unbelievers convincing reasons for accepting their faith.
However, it is far from clear that the converse holds: that accepting the truth
of the theory of evolution is rationally incompatible with continuing to hold
religious beliefs. Since religious believers need make no empirical claims
regarding this world, there need be no conflict. Faith may be sufficient, by
the believers’ lights.

This is a short book intended for a
wide audience. Accordingly, arguments are sketched rather than developed fully.
In a book which is so polemical and which argues for views which are so
controversial, this leads to frustration. It is certainly true that, from
Herbert Spencer in Darwin’s day, to E.O. Wilson and the current crop of
evolutionary psychologists in ours, absurdly inflated claims for the importance
of evolution to society and our self-understanding were and are made. Spencer
thought to place politics upon an evolutionary footing, while Wilson claimed that
morality could be replaced by evolutionary thinking. Dupré is certainly right
in dismissing this kind of claim. But is he right in thinking that no claim of
this kind, no matter how weak, could be correct? That is far from clear.
Suppose that our emotions are the product of evolution, and that they play a
central role in morality as many psychologists and philosophers believe. This
might imply two things: First, that our evolutionary history sets certain,
extremely broad, constraints upon a possible system of morality for us, and,
second, that rational creatures who had taken a different evolutionary path
would have a different moral system. Dupré seems committed to denying both
claims. Whether he is justified in this or not depends upon the further development
of his arguments, a further development this frustratingly short book cannot
give us.

Link:

• Review of
  Human Nature and the Limits of Science

© 2004 Neil Levy

Dr Neil Levy is a fellow of the Centre for Applied Philosophy
and Public Ethics at Charles Sturt
University, Australia. He
is the author of two mongraphs and over a dozen articles and book chapters on
Continental philosophy, ethics and political philosophy. He is currently
writing a book on moral relativism.

Categories: Philosophical, General