Informavores have choices

Michael Rutter is impressed by arguments that free will is in our cells

Many people suppose that science is the enemy of free will; that the more that we know about how genes and environmental influences come together to shape our behaviour, the less opportunity there will be to invoke some hypothetical third force of free will that is outside the biological determinism that characterises natural science. Religion argues for the existence of a "soul" that is outside biology, but if science rejects that view, what is left?

Daniel Dennett maintains an uncompromisingly materialistic stance and utterly rejects a dualistic concept of consciousness.

Nevertheless, within the confines of science, Dennett argues persuasively that free will is real, that it derives from our evolutionarily determined biology and that the advances in knowledge to be expected over the decades ahead will increase the importance of free will rather than diminish it.

That is because a greater understanding of genes and the environment will allow us to use deterministic principles to bring about changes that we decide are desirable, and that represent our choices and not just our reflexes.

Put simply, the key point is that our biology means that "we are designed by evolution to be informavores - epistemically hungry seekers of information, in an endless quest to improve our purchase on the world, the better to make decisions about our subjectively open future". We have evolved to be entities designed to change our natures in response to interactions with the rest of the world. We are thinking, feeling beings with the capacity to imagine what might be, to conceptualise the consequences of different actions, and hence the capacity to evaluate the ends and not just the means. It is language, and the thought processes that go with language, that provides that capacity, a capacity that marks us off from other species. Thus "recognising our uniqueness as reflective, communicative animals does not require any human 'exceptionalism' that must shake a defiant fist at Darwin and shun the insights to be harvested from that beautifully articulated and empirically anchored system of thought".

Dennett quotes with approval what Merlin Donald intended to serve as an antidote to Dennett's views, in which Donald argues that his (Donald's) book "proposes that the human mind is unlike any other on this planet, not because of its biology, which is not qualitatively unique, but because of its ability to generate and assimilate culture". It is just that ability that is central to Dennett's concepts; the only difference is that Dennett argues convincingly that this is part of our biology.

As always, Dennett brings together science, philosophy and common sense, but he does so in a way that takes seriously opposing views and accepts the need to counter them through logic and empirical findings. The publisher's blurb describes Dennett as a polemicist, and I suppose that he is in the sense that he loves to challenge orthodoxies; but he is no evangelist castigating his opponents. Rather, he relies on evidence, being willing (unlike evangelists) to recognise what is not known or what remains either uncertain or present as a problem. He warns us to beware of rhetorical questions because they imply a reductio ad absurdum argument that provides a hiding place for some unexamined assumptions. Dennett is skilled in his detection of such hidden assumptions, and his own arguments are clever, but he is consistent in playing straight with both the concepts and the empirical findings. What he does supremely well is dissect out the key issues and consider just what they mean.

Thus, he shows convincingly that determinism does not imply inevitability (because avoidance and prevention may be possible); that indeterminism would not give more room for manoeuvre (because it is determinism that allows us to decide how to change things); and that real options (and not just apparent ones) exist in a deterministic world. Dennett uses thought experiments to show the logic of what is possible but also turns to real-life examples to illustrate what happens. He uses spinning a fair coin as a way of noting that the randomness comes not from a lack of deterministic causes, but rather from amplifying the sum of forces operating. He also brings out the scientific value of randomness by drawing attention to the randomised controlled trial of medical treatments as an example of randomisation severing the causal links that would otherwise determine which treatment each patient chose (and hence which would seriously interfere with the possibility of finding out whether the treatment truly is effective).

Computers, Dennett notes, can be programmed to adapt to changes in the environment and to learn from mistakes. Similarly, we are not designed to have fixed natures. But we differ from computers in terms of the additional ability that comes with language, of being able to ask for, and give, reasons, and to imagine what could be created. Meaningful choice involves two requirements: information and a path for the information to guide.

Increasingly, we have both. Genetic determinism is dismissed as a nonsense because, once the processes are understood, interventions can be invented to prevent effects (the dietary treatment of phenylketonuria provides a telling illustration but so does the correction of short sight by means of spectacles). It is in this way that more and better scientific knowledge will increase the choices.

Appeals that we should not interfere with nature get equally short shrift.

The whole of medicine involves such interference - whether through antibiotics to counter infections, drugs to reduce cholesterol levels, coronary bypass surgery to improve the blood supply to the heart or hip replacements. "Every human artifice thwarts or redirects some trend of nature; the trick is to figure out enough about how nature's patterns are put together so that our interference in them will achieve the results we want". Perhaps, Dennett suggests, the worry is that science will give us too much freedom. If your child lacks "true grit", maybe you will be able to buy him some artificial grit. Why should all self-improvement be done the old fashioned way? The answers are not obvious and Dennett is well aware of both the ethical and practical problems, but the questions need to be addressed directly, not distorted by ill-advised attempts to smother them by invoking "against nature" arguments.

Parts of the book require the reader to engage in some serious thinking, for example in following through the thought experiments or considering why the fact that the physiological evidence shows that the brain acts before you yourself recognise that you are deciding does not rule out free will.

The evidence on the time taken for messages to be passed from the brain to the muscles bringing about the action is fascinating, and it does force some reconsideration of how thought processes operate. However, decisions about what needs to be done in any given situation are not confined to the moment of action. Often there has been considerable consideration of alternatives and planning what to do long before the message to act is transmitted.

Dennett writes with great clarity, and readers are taken through the issues and arguments step by step. He also uses wonderful turns of phrase.

Throughout, there is the ever-present sense of fun and mischievous irreverence that makes the book an enjoyable, as well as a serious, read.

His own great gift with words is matched by his choice of quotations. Thus the H. L. Mencken aphorism that "conscience is the inner voice that warns us someone might be looking" and the Alcoholics Anonymous advice to "fake it until you can make it" enliven the discussion on the extent to which we can be deceived or deceive ourselves.

By any standard, this is an outstandingly good, as well as important, book.

There is no better philosophical exponent than Dennett of what evolutionary biology really means. It is a book to be read because it is so entertaining, but also a book that should make most readers think afresh about their assumptions.

Sir Michael Rutter is professor of developmental psychopathology, Institute of Psychiatry, London.