Since writing about Billie Holiday’s song Me, myself and I, the question of ‘who is I?’ has been gnawing away inside my mind. A couple of weeks ago I picked up a second-hand book in Thirsk that’s turned the gnawing into a gnashing. The book is called Into the silent land, and it’s by a British neuropsychologist, Paul Broks.
The book is an episodic collection of stories, most culled from Broks’s clinical practice, a few from his personal life, that illustrate the often uncertain relationships between the brain – often the damaged or impaired brain – and human behaviour and character. One model, possibly, was Oliver Sacks’s well-known collection of case studies, The man who mistook his wife for a hat. Tellingly, Broks says that he ‘studiously avoided [Sacks’s works] while writing this book’.
Into the silent land: travels in neuropsychology is a beautifully written book. It mixes genres and styles – parable, meditation, dialogue, clinical notes, personal recollection – with great art and variation. But there’s a silver thread running through all the chapters: the puzzling connection, or lack of if, between the ‘dollop of mush’ (Broks’s phrase) that is the physical reality of the brain and the limitless library of thoughts, memories, feelings and sensations that seem to inhabit our ‘minds’. One prominent shelf in this library is labelled ‘identity’, and it’s the problem of the nature or grounding of personal identity that causes Broks most perplexity.
He introduces us to the question with the aid of the human face, and the ‘irresistible illusion’ that behind the face of the person we’re looking at is a ‘self’. ‘We see the signal of consciousness in a gleaming eye and imagine some ethereal space beneath the vault of the skull’. But this is an illusion, says Broks: ‘the brute fact is there is nothing but material substance: flesh and blood and bone and brain. I know. I’ve seen’.
Not only do we assume that other people have ‘selves’, we believe that we ourselves – what a presumptuous word ‘ourself’ is! – also possess selves. ‘We create our selves by inference: automatically and irresistibly. In doing so we ride the rails of the deepest human convention but, at root, it is just that, a convention. The self is not an intrinsic feature of the brain, and it is possible to become derailed …’
Having given his students, and us, a whistle-stop tour of the parts of the brain and their neural networks, Broks encapsulates his problem: ‘where is the mind in this tangled wood of neurons and nerve fibres? It isn’t anywhere. And the self? What did you expect? A genie in a bottle?’
If the self can’t be located by staring at the grey matter, suggests Broks, maybe it lies elsewhere, not in an single object, but in the relations of the brain with other parts of the body, and, even more important, with the external social world. We all of us assemble a self ‘as a device we humans employ as a means of negotiating the social environment’. In fact, this concept has a long history, back to early Buddhist teachings and to David Hume, who denied the existence of a singular ego or self.
The problem of the ‘non-existence’ of the self seems most acute when you consider the continuity of identity over time in the same individual – yourself. Broks relates how he showed his students an old video of himself as a young researcher interviewing a patient with brain disease. ‘He [the patient] is dead now and it occurs to me that every molecule of my younger self has been replaced with the passage of time. In a sense, neither of those bodies has survived.’ Does recollection of one’s younger sense constitute one’s identity? If so, what if I suffer from amnesia about a period in my past? Does it follow that I have nothing in common with the youth I was then? Maybe, Broks suggests, identity is just a series of associations or rough approximations. His analogy is with Wolverhampton Wanderers, the team he supported as man and boy. The team is completely different now, the club was revived after twice going into liquidation, its stadium was demolished and rebuilt, and so on. And yet there is still an identifiable entity called Wolverhampton Wanderers.
In his penultimate chapter Broks, who has steeped himself in the philosophical literature of mind and body, conducts a thought experiment, in the form of a science fiction story. Travel to Mars and back to Earth is commonplace, thanks to the teleportation machine, which clones every atom of the traveller and rebuilds him or her instantly on the other planet. The story’s narrator is the victim of a rare failure of the machine. Usually the ‘original’ version of the traveller from Earth is vaporised, through a process called ‘discorporation’, when the new, Martian copy is created. But on this occasion, though the Martian version has been formed successfully, the narrator emerges from the machine on Earth intact. Derek, the engineer supervising the machine – his name is borrowed from that of the philosopher Derek Parfit, who invented the transportation story – is puzzled.
Discorporation is necessary because it is intolerable to have two people of identical composition roaming the solar system. Because over time they will not in fact be precisely identical: each will accumulate experiences that will multiply their differences. The narrator, whose replica has probably already phoned his wife to report his safe arrival on Mars, will have to appear before the Subcommittee on Personal Identity to discover whether his continued existence breaks the Proliferation of Persons Act. The outlook isn’t hopeful.
In the meantime Derek tries to convince him that his destruction, if that is what is decreed, will be no disaster. He outlines two conflicting theories of personal identity. The dominant, Ego Theory assumes a ‘pilot in the cockpit’ of the individual, a manager or controller of all thoughts and sensations, persisting unchanged through one’s life. Bundle Theory, on the other hand, denies the existence of an essential ‘I’. What happen within us is just a stream of experiences, thoughts and actions, and life is the series of them all, bound together in various complex ways. The Bundle Theory, suggests Derek, is the one that fits the physiological facts of the brain best.
The narrator is unpersuaded. Bundle Theory simply doesn’t tally with the way we think about ourselves. The idea of a central self seems much more to us than what Derek calls, dismissively, a ‘fact of grammar’, ‘a false belief about ourselves’.
Derek reminds him that he’s already been teleported several times already, and that he said goodbye to his ‘original’ self many years ago. And yet he did not find his situation intolerable then: ‘teleportation is no more threatening or problematic than travelling on life’s journey from one day to the next’. The important thing is psychological continuity: the bundle of thoughts we wake up with are sufficiently similar to those we went to bed with the night before that we don’t worry. The Martian replica is the equivalent of that waker. Even death does not bring a complete end to the series, since memories, influences, advice followed can all be regarded as extensions of one’s own bundle. Their continuation is assured by others. Bob Holman, the academic and community activist who died recently, said ‘If I have achieved anything, I hope it is seen in other people, not me.’
Derek admits, though, that even Bundle philosophers, from Hume to Thomas Nagel, admit that the theory is too much for most people to accept.
The narrator finally dozes off, and dreams that he sees a younger version of his wife in the company of a man with no face. He wakes to find a white envelope pushed under the door. It’s an invitation from the Subcommittee on Personal Identity to appear before them later that morning.
The microscopic beams of neurological science are homing in with ever greater refinement on the minute connections of the human brain, in much the same way that physicists have explored the world of particles in detail far beyond those once regarded as the ultimate in smallness. Whether they will ever find the locus and nature of personal subjective experience is doubtful. Whether they will give us enough confidence in the explanatory power of ‘bundles’ to be able to consign the self to the world of mythology is also uncertain. And there’s another point, as Broks observes. Our social system, including our entire system of justice, relies on the notion of a coherent and directing personal identity, an identity that can be held to account for the actions of its owner. So perhaps, if the Ego is really a fiction, it may be a necessary fiction, a mental system that has evolved to allow us to live successfully as connected individuals.