The philosophical debate on free will has a way of blowing people’s minds when they first encounter it. And fair enough: thinkers who deny the existence of free will insist that nobody ever meaningfully chooses what they do. Earlier this week, for example, walking past a cafe, I stopped to buy a coffee, and certainly it felt as if I could have chosen otherwise. Nobody forced me inside at gunpoint, and I’m not enslaved to an overpowering caffeine addiction. I just wanted coffee. But hold on: that desire, and the bodily movements involved in the purchase, were caused by events in my brain. And what caused them? Prior brain events, interacting with my environment. My brain itself, for that matter, is only the way it is because of my genes and upbringing, both of which resulted from the chance meeting of my parents – and so on, in an unbroken chain of causes, back to the big bang.
If our actions are “determined” in this way, the moral implications are dizzying. It becomes hard to see how to blame a Harold Shipman or Charles Manson – or a Vladimir Putin or Donald Trump – for anything they do. If I’d been born with Shipman’s exact genes, and experienced his precise upbringing, I’d simply have been him; there’s no secret corner of my psyche where a ghostly “free will” lurks, capable of making better decisions. (I’m ignoring randomness in quantum physics here, in the interests of my sanity; you’ll have to take my word for it that few free-will theorists think it makes much difference.)
Perhaps because denying free will feels so counterintuitive – while talk of inner ghosts is plainly unscientific – a majority of philosophers are “compatibilists”. They believe our actions are in fact determined, but that we nonetheless have free will. In a free-will sceptic such as me, this is apt to prompt murmurings about having one’s cake and eating it. But the compatibilists do have a point: if you want a coffee, and nothing stops you from getting one – you can afford it, the cafe’s open, etc – then in what sense is your purchase not freely made? Because you didn’t choose to want coffee in the first place? But to meet that definition of freedom, you’d have to be free not to want what in fact you do want. Which is a very strange notion indeed.
Into this bewildering terrain steps the celebrated behavioural scientist Robert Sapolsky, who sets out in Determined to banish free will once and for all – and to show that confronting its nonexistence needn’t condemn us to amorality or despair. It’s only one aspect of the book’s strangeness that he does this in a style that often calls to mind a hugely knowledgable yet stoned west coast slacker. (I’m still recovering from his reaction, in a book crammed with footnotes and diagrams of motor neurons, to the conclusion that we don’t control our lives: “Fuck. That really blows.”)
His strategy is an ambitious one: to track every link of the causal chain that culminates in human behaviour, starting with what’s happening in the brain in the final few milliseconds before we act, all the way back to how our brains are shaped by early experiences, and even before that, all mostly at the fine-grained level of neurotransmitters and genes.
Along the way, he makes impassioned arguments against such ideas as “grit”, which seem to suggest that those raised in situations that tax their willpower could just choose to develop more of it. Yes, there are people who “overcame bad luck with spectacular tenacity and grit” – but their capacity for tenacity and grit was bestowed by luck, too. Everything is luck, including whether or not you have the right character traits for dealing with bad luck. In the words of the free-will sceptic Galen Strawson, “luck swallows everything”.
Determined is a bravura performance, well worth reading for the pleasure of Sapolsky’s deeply informed company. What’s less clear is whether this inventory of the causes of human behaviour should change anyone’s position on free will. After all, most free-will deniers make their case on a priori grounds, meaning that their arguments aren’t dependent on specific scientific findings. If the entire present state of the world was caused by the entire state of the world just before that, and the world back then was caused by the state of the world before that, and so on, then the details of exactly what’s causing what don’t seem to matter.
Meanwhile, compatibilists, by definition, have already made their peace with the idea that everything is fully caused, and insist it’s no threat to free will. So Sapolsky’s insistence that everything is really, really fully caused seems unlikely to trouble them. Perhaps there are people who believe free will hides out in some part of the brain not yet charted by scientists. If so, this book will set them right. But in philosophy, at least, that isn’t a common view.
Maybe it is a subliminal awareness of these issues that explains Sapolsky’s tic of informing the reader how much he disliked writing large chunks of the book. “Giving this section this ridiculous heading reflects how unenthused I am about having to write this next stretch,” he writes at one point. About 170 pages later: “I really do not want to write this chapter, or the next one.” To which another kind of free-will denier may reply, well, maybe you needn’t have done. Once you’ve made the basic case that there’s no space for free will, you’ve said it all.
Later in the book, when he turns to the question of how we should live in the absence of free will, Sapolsky’s humane worldview comes to the fore. Some argue that realising we lack freedom may turn us into moral monsters. But he makes a moving case that, really, it’s a reason to live with profound forgiveness and understanding – for seeing “the absurdity of hating any person for anything they’ve done”. It is the ultimate philosophical grounding for the idea that “there but for the grace of God go I”. A familiar paradox lurks here, as with any discussion of how we ought to respond to the absence of free will: if there’s no free will, surely we’re just going to respond however we respond? But this doesn’t mean Sapolsky’s absorbing and compassionate book won’t change how people think, or how they behave towards one another. It just means they won’t have freely chosen to make that change.
• Determined: Life Without Free Will by Robert Sapolsky is published by Bodley Head (£25). To support the Guardian and Observer order your copy at guardianbookshop.com. Delivery charges may apply
