The riddle of free will goes unsolved

Neuroscientist Michael Gazzaniga's Who's In Charge? Free will and the science of the brain is fascinating, but doesn't deliver on its promise

ABOUT half way through this fascinating book, Michael Gazzaniga harks back to his previous one, Human. He wanted to call it Phase Shift, he says, but his publisher overruled him.

Gazzaniga - one of the giants of modern neuroscience - tells this story to illustrate a point about the difference between animal and human brains, but by the end of the book it has taken on a different complexion. Because while Who's In Charge? is full of wonderful material, anybody expecting an answer to the vexing question of free will is going to come away disappointed.

The book is based on Gazzaniga's contribution to the Gifford lecture series, established in 1887 at four prestigious British universities to "promote and diffuse the study of Natural Theology in the widest sense of the term". It romps around the intersection of neuroscience and the human condition, from Gazzaniga's own astonishing work on split-brain patients to social neuroscience, consciousness, morality and more. Free will gets a look in, but is far from the centrepiece. To subtitle the book Free will and the science of the brain frankly sets up expectations that are never met, and which prove very distracting.

As one example of how the title does disservice to the content, Gazzaniga opens his final chapter with the harrowing story of Lawrence Singleton, who in 1978 raped a teenage girl in California, hacked off her forearms with an axe and left her to die by the roadside. She survived, and her testimony helped put Singleton away. He got 14 years but served just eight. After being released for good behaviour, he went on to murder a prostitute. He died on death row in 2001.

As I read this horrific tale, I was expecting it to be the point where Gazzaniga finally takes on the problem of free will. Singleton's acts were monstrous, but was he really responsible? Frustratingly, the story turns out to be a preamble for a discussion of how our brains deal with justice and retribution. Interesting stuff, but my own brain was plotting a bit of justice and retribution of its own for being misled.

So what of free will? The problem is a familiar one. We live in a deterministic universe. Given enough information about its present state, we could extrapolate to any past or future state with 100 per cent accuracy. Everything that has or will happen was determined at the big bang - and given that our brains are part of the physical universe, free will does not exist. Depressingly, neuroscience itself offers little comfort that this isn't the case.

Gazzaniga's solution is also a familiar one. Post-Newtonian physics has retreated from strict determinism in the form of quantum mechanics, chaos theory and emergence. Perhaps neuroscience can use them to rescue free will? Gazzaniga throws all of these at the problem but ultimately they bounce off, leaving determinism's hard and unforgiving core intact.

There is a great book waiting to be written on free will. This isn't it, but it's worth reading all the same.