How to attain a free spirit

This is an amazingly clear book about free will - about the way in which we take decisions. It effectively lays to rest a ghost that still haunts us from the Newtonian age, especially from writers such as Julian Offray de la Mettrie, namely the deadening influence of mechanism and the obsession with analogies from simple clockwork machinery.

Chris Nunn forcibly points out that we - our conscious selves - are not helpless extras, shadows dragged along by remorseless clockwork bodies.

Instead we are something much larger: complex beings, creatures whose mind and body - inside and outside - are just two complementary aspects in a wider whole.

Since these two are not separate, competing items, we do not need T. H.

Huxley's "epiphenomenalist" theory - that consciousness is just an inert by-product of the body, a steam whistle that has no effect on the working of the engine. That - and indeed the whole mechanist analogy - was, of course, always somewhat bizarre. It is not clear how this independent engine was ever supposed to have been invented unless conscious thought had gone into designing and driving it. In fact, the concept of a machine is one that already involves the work of mind.

Today, it is becoming plain - despite Francis Crick's and Benjamin Libet's theories on consciousness and neuroscience, and a lively school of thought surrounding zombies - that bodies without the power of thought would not know what to do and so could not make their own decisions. For active, enterprising animals such as ourselves consciousness is not an optional, supernatural extra, but an evolutionary necessity. The reason it has taken us so long to see this is that, after Huxley's time, the behaviourists conducted a huge campaign in psychology to play down the role of conscious mind in human life. But this approach backfired so spectacularly that the tide turned and "consciousness studies" took shape as a vigorous and respectable inquiry, an exploration in which Nunn has played an effective part.

Confronting epiphenomenalism, Nunn points out that it has never been realistic to see ourselves as pure minds struggling against imprisonment in alien, mechanical bodies. The constraints that prevent free decision-making are mostly not physical, but social. They relate to ways of thinking that we grow up with - and take for granted.

Nunn also tackles the ontological argument. If we really do ditch the Cartesian mechanistic approach - if we finally stop dividing the world into shadowy minds and inert, lifeless matter - what shall we replace it with? Here, Nunn moves into a rather confusing stratum of physical theories, ingeniously using concepts such as chaos, complexity and quantum entanglement to conclude that, in some sense, the basic stuff of the world is not superstrings, but information or stories.

This kind of thinking does indeed undermine our residual dualism. It kills the obsessive belief, inherited from the Greek atomists, that the only reality is solid, tangible matter. Nunn's book points us in some interesting directions.

Mary Midgley was formerly senior lecturer in philosophy, Newcastle upon Tyne University. Her most recent books are The Essential Mary Midgley (an anthology of her work) and an autobiography, The Owl of Minerva .