Much of Human Nature and the
Limits of Science sets out an argument against evolutionary psychology and
the way that the science is used to draw political conclusions. I have discussed this aspect of the book
elsewhere (in The Philosophers’
Magazine) and here I will simply say that Dupré makes a very convincing
case that, in his words, “evolutionary psychology is … a largely bankrupt
approach to understanding human behavior” (p. 15).

The sixth chapter turns to rational
choice theory as used in economics and the rest of the social sciences. Dupré concedes that using rational choice
and game theory may be helpful in understanding patterns in people’s purchasing
and selling property and goods. But he
argues that it is a mistake to extend these models to the rest of human life,
and he decries the imperialistic tendencies of rational choice theory to quash
other ways of understanding social behavior. 
His two examples to make his case are Philipson and Posner’s economic
approach to understanding the AIDS epidemic and Nobel Prize winner Gary
Becker’s account of human partner choice in his Treatise
on the Family. Both accounts
assume that humans are fundamentally motivated by personal-utility-maximizing
considerations. They give little or no
place for altruism or more complex motivations. Dupré is highly critical of such reductionist approaches, which he
argues lead to “the obliteration of the most interesting and important aspects
of human behaviour” (p. 132) and instead he promotes non-reductionist
metaphysical pluralism.

Dupré’s arguments are simple and
somewhat obvious; what is surprising is that serious thinkers were ever tempted
to take the oversimplifications of evolutionary psychology and rational choice
theory seriously. These theories may
well have a place in the overall explanation of human behavior, but it takes
only brief thought for it to be clear that they cannot provide the whole
story. Dupré makes his case well, but
he is hardly the first to point out the deficiencies of evolutionary psychology
or rational choice theory as global approaches to understanding human social
life, and Dupré himself often refers to the other critics who have made similar
points previously. It is only in the
final chapter on free will that Dupré’s book makes strikingly original
claims.

In Chapter 7, Dupré’s aims “to show
how disposing of both the bad metaphysics and its scientistic spawn opens the
way for a proper account of human autonomy” (p. 154). He argues that we do not have good reason to believe in
determinism, and without determinism, there is room for an account of freedom
of the will. This is well-trodden
ground, but Dupré’s argument shows clear understanding of how simple randomness
(from the phenomena of quantum theory or chaos theory, for example) does not
help to understand free will. The
strength of his account is to provide an alternative way of understanding the
relationship between the falsity of determinism and the possibility of free
will.

Dupré holds that freedom has little
conceptual connection to being able to act otherwise. He is concerned to develop the concept of the autonomous agent as
the originator of an action. This idea
has been developed by the philosopher Roderick Chisholm and is captured by the
phrase, “agent causation.” But unlike
Chisholm, Dupré does not argue that agent causation can provide an account of
alternative possibilities of action, and he takes agent causation to be similar
to other forms of causation. Indeed, he
argues that human freedom relies on our causal powers.

Traditional determinism is
committed to the thesis of causal completeness, which requires that
“there be some quantitatively precise law governing the development of every
situation” (p. 157). Even an
indeterministic theory such as quantum mechanics is committed to causal
completeness, according to Dupré; it assigns probabilities to events rather
than making predictions with certainty, but it still is governed by the
assumption that it is applicable to every physical event. Dupré rejects the thesis of causal
completeness, because he holds that, “few, if any, situations have a complete causal
truth to be told about them” (p. 157), and “causal order is everywhere partial
and incomplete” (p. 158). Of course,
Dupré believes that objects have causal powers, and indeed, the key to human
autonomy lies precisely in the fact that we are dense concentrations of such
powers.

If the behavior of the
microphysical components of our bodies is determined, then it follows that the
movements of our bodies are determined. 
The exact relation between the higher levels of descriptions and the
lower levels is a matter of philosophical dispute; reductionism holds that the
higher levels are reducible to the lower levels, eliminativism holds that the
higher levels are simply false and only the lower levels of description are
true, and supervenience holds that both levels of description are true and one
level is not reducible to another, but the higher level does in a
metaphysically significant way depend on the lower level. The same relationships between levels will
hold even if determinism is not true, but causal completeness is. Dupré insists that all these view of the
relationship between different levels of description make the causal powers of
ordinary sized objects at best epiphenomenal. 
Higher structural levels lack causal autonomy. But with the denial of causal completeness, one can save the
causal autonomy of higher structural levels. 
Structures at each level have distinctive causal powers, and the
different levels will interact with each other. (Dupré first set out these ideas in his groundbreaking 1993 book The
Disorder of Things.)

Dupré’s argument against
determinism starts by pointing out what a strong metaphysical claim it makes,
and to shift the burden of proof onto determinists to make the case for their
view. He then argues that there is nothing
in our empirical knowledge of the world to suggest that determinism must be
true. Indeed, even the greatest
successes of scientific reductionism are modest and limited, and give no
support to a strong claim of universal determinism. The success of apparently
deterministic theories such as Newton’s laws of motion is restricted to simple
systems such as the solar system. As
has been pointed out by Nancy Cartwright in her influential 1983 book How
The Laws of Physics Lie, the laws of physics rarely describe the actual
behavior of objects, and are only true under a ceteris paribus (other
things being equal) condition. Most
systems are very complex, and so other things are not equal. Dupré moves from this straightforward point
to a more surprising claim:

The assumption that the laws of Newtonian mechanics
are, in some sense, carrying on regardless under the overlay of increasingly
many interfering and counteracting forces is not merely sheer speculation, but
actually of dubious intelligibility. 
What are these laws supposed to be doing, given that the objects,
subject to such diverse other influences, are not behaving in any sense in
accord with them? (p. 166)

This is a bizarre suggestion, for it seems that
Dupré is suggesting that some laws of motion cease operating in cases of
complex interaction of objects. His
idea that the continuation of the laws of physics might even be unintelligible
in complex situations is surely just plain wrong, since most physicists would
claim to have a clear and distinct idea of what it means. It is not clear why he makes this claim,
since he does not need it order to attack his target of causal
completeness. His basis is the
empiricist view that we should not extrapolate beyond the available evidence,
and there is little empirical evidence for causal completeness.

An interesting distinction made by
Dupré is worth mentioning here. He
concedes that science might do well to make a methodological assumption of
determinism; that is to say, science might make progress assuming that there is
an underlying order governing complex interactions, and this might lead to
successful scientific laws. But the
helpfulness of the methodological assumption does not prove the truth of the
metaphysical thesis of determinism. All
is shows is that the methodology helps us to discover what order there is in
the world.

Furthermore, Dupré emphasizes that
there is plenty of evidence, including random events such as coin tosses, that
the world is genuinely indeterministic. 
While not conclusive, this evidence is certainly counterbalances the
evidence from predictable events that the world is deterministic. And if there is some indeterminism in the
world, then it will not be contained but rather will have effects far and wide. Dupré concludes this part of his discussion
by pointing out that if there is some indeterminism in the world, the empirical
evidence for causal completeness will be even weaker than it would be in a
determinist world, and it becomes even less clear what we might mean by laws
being true ceteris paribus, because it is not clear what we are holding
to be equal.

If the evidence available to us
does not lend good support to the thesis of causal completeness, then what
leads so many to believe in it? Dupré
suggests that our intuitions may rest on our experience of complex highly
organized structures such as machines and biological organisms. It must at least be true that there must be
some order in the world for it to be even possible to successfully build
machines. But Dupré points out that it
takes enormously skillful engineering to create machines, and one of the marks
of a successful design is that it minimizes the unpredictability of the
operation of a machine.

Dupré then points out that
biological organisms are also highly reliable, even though they were not designed,
and unlike machines, they lack controls. 
Humans have autonomy, by which Dupré means that we have the capacity to
control ourselves. He emphasizes that
our many skills and capacities are shaped by our social context, and they
depend on that context. But Dupré
agrees with Kant that it is the human capacity to guide our actions by
principles that makes human autonomy worth caring about, for it is our ability
to be guided by our conception of the good that gives us hope that we can make
the world a better place. He further
argues that moral principles are essentially linguistic, and as such, “depend
essentially on the relationship between the individual and society” (p.
181). He takes care to assert that this
relationship is a dialectical one, i.e., it is one of mutual interaction and
dependency.

One might wonder what implications
Dupré’s view has for the study and treatment of mental illness, and
fortunately, in the closing pages of the book, he gives the reader some hints
using the example of attention deficit hyperactivity disorder (ADHD). In the Introduction to the book, Dupré
commented on the well-known increase in the diagnosis of the disorder and the
associated increase in the prescription of the stimulant medication
Ritalin. He warns of the dangers of
reductive approaches to understanding children’s restlessness, wonders how much
research has been done comparing the relation of different teaching techniques
to ADHD compared to the research done showing the efficacy of
psychopharmacological remedies, and suggests that drugged children are “the
price we pay for action on the basis of the reductionist myth” (p. 15). In the final chapter, he argues that when we
recognize the complexity of human behavior, we should then expect that a
pharmacological solution might have both positive and negative effects. Understanding the value of pluralism shows
that the teaching of medical students should be broadened rather than becoming
increasingly narrow.

These conclusions may strike
humanistic philosophers as banal and they can of course be supported on far
less controversial grounds than the metaphysical pluralism advocated by
Dupré. It takes only a little
appreciation for the limitations of scientific knowledge of human life to see
that it is important to be conscious of the social influences on human behavior
and the dangers of a reductionist approaches to understanding the mind. Nevertheless, Dupré’s advocacy of pluralism
is very welcome and timely in the current reign of neurophysiological
approaches to mental disorders.

It is Dupré’s discussion of the
relationship between autonomy and the rejection of causal completeness that is
of more substantial philosophical interest. 
His suggestions are certainly interesting even if they are somewhat
sketchy; one might wish that his ideas were spelled in more detail in order to
be able assess them fully, although to be fair, he does refer to some of his
previous published work in support of his current arguments. To a large extent, one’s sympathy with his
views about freewill will be related to one’s sympathy to what he refers to in
his Acknowledgements as the Stanford School of the philosophy of science, and
in particular the philosophy of Nancy Cartwright on scientific laws and
causality, as well as Dupré’s own work on the disunity of science. His view that autonomy is a matter of a
person’s causal powers does not by itself shed much light on the nature of
autonomy. For example, it does nothing
to help resolve controversies about whether people who are diagnosed with
addictions and obsessive-compulsive behavior, or even tics, have autonomy or
not. In one footnote (p. 176) Dupré says that “‘I’ refers to the whole
organism, not just some neurologically salient bits of it” but this does not
help us to understand the autonomy of behavior that results from some kind of
psychological conflict or is in some way a product of structures at different
levels of the whole organism.

One might hope that Dupré or other
philosophers who are impressed by his approach will further develop his
interesting suggestions about freedom. 
Yet Human Nature and the Limits of Science is an exciting book
for philosophy and deserves a wide readership. 
It is written in an approachable style that should be accessible not
only to professional philosophers and graduate students, but also to
upper-level undergraduates and philosophically-inclined social scientists.

 

© 2002 Christian Perring. All rights reserved.

Christian Perring,
Ph.D., is Chair of the Philosophy Department at Dowling College, Long Island.
He is editor of Metapsychology Online Review. His main research is on
philosophical issues in psychiatry. He is especially interested in exploring
how philosophers can play a greater role in public life, and he is keen to help
foster communication between philosophers, mental health professionals, and the
general public.

Categories: Philosophical