because only the human brain was physically able to reply. The jewel received input from the senses, but had no control over the body, and its intended reply coincided with what was actually said only because the device was a perfect imitation of the brain. To tell the outside world ‘I am the jewel’ — with speech, with writing, or with any other method involving the body — was patently false (although to
think it
to oneself was not ruled out by this line of reasoning).
However, in a broader sense, I decided that the question was simply misguided. So long as the jewel and the human brain shared the same sensory input, and so long as the teacher kept their thoughts in perfect step, there was only
one
person,
one
identity,
one
consciousness. This one person merely happened to have the (highly desirable) property that if
either
the jewel
or
the human brain were to be destroyed, he or she would survive unimpaired. People had always had two lungs and two kidneys, and for almost a century, many had lived with two hearts. This was the same: a matter of redundancy, a matter of robustness, no more.
That was the year that my parents decided I was mature enough to be told that they had both undergone the switch— three years before. I pretended to take the news calmly, but I hated them passionately for not having told me at the time. They had disguised their stay in hospital with lies about a business trip overseas. For three years I had been living with jewel-heads, and they hadn’t even told me. It was
exactly
what I would have expected of them.
‘We didn’t seem any different to you, did we?’ asked my mother.
‘No,’ I said — truthfully, but burning with resentment nonetheless.
‘That’s why we didn’t tell you,’ said my father. ‘If you’d known we’d switched, at the time, you might have
imagined
that we’d changed in some way. By waiting until now to tell you, we’ve made it easier for you to convince yourself that we’re still the same people we’ve always been.’ He put an arm around me and squeezed me. I almost screamed out, ‘Don’t
touch
me!’ but I remembered in time that I’d convinced myself that the jewel was No Big Deal.
I should have guessed that they’d done it, long before they confessed; after all, I’d known for years that most people underwent the switch in their early thirties. By then, it’s downhill for the organic brain, and it would be foolish to have the jewel mimic this decline. So, the nervous system is rewired; the reins of the body are handed over to the jewel, and the teacher is deactivated. For a week, the outward-bound impulses from the brain are compared with those from the jewel, but by this time the jewel is a perfect copy, and no differences are ever detected.
The brain is removed, discarded, and replaced with a spongy tissue-cultured object, brain-shaped down to the level of the finest capillaries, but no more capable of thought than a lung or a kidney. This mock-brain removes exactly as much oxygen and glucose from the blood as the real thing, and faithfully performs a number of crude, essential biochemical functions. In time, like all flesh, it will perish and need to be replaced.
The jewel, however, is immortal. Short of being dropped into a nuclear fireball, it will endure for a billion years.
My parents were machines. My parents were gods. It was nothing special. I hated them.
* * * *
When I was sixteen, I fell in love, and became a child again.
Spending warm nights on the beach with Eva, I couldn’t believe that a mere machine could ever feel the way I did. I knew full well that if my jewel had been given control of my body, it would have spoken the very same words as I had, and executed with equal tenderness and clumsiness my every awkward caress
— but I couldn’t accept that its inner life was as rich, as miraculous, as joyful as mine. Sex, however pleasant, I could accept as a purely mechanical function, but there was something between us (or so I believed) that had nothing to do with lust, nothing to do with words, nothing to do with
any
tangible action of our bodies that some spy in the sand dunes with parabolic microphone and infrared binoculars might have discerned. After we made love, we’d gaze up in silence at the handful of visible stars, our souls conjoined in a secret place that no crystalline computer could hope to reach in a billion years of striving. (If I’d said
that
to my sensible, smutty, twelve-year-old self, he would have laughed until he hemorrhaged.)
I knew by then that the jewel’s ‘teacher’ didn’t monitor every single neuron in the brain. That would have been impractical, both in terms of handling the data, and because of the sheer physical intrusion into the tissue. Someone-or-other’s theorem said that sampling certain critical neurons was almost as good as sampling the lot, and — given some very reasonable assumptions that nobody could disprove — bounds on the errors involved could be established with mathematical rigour.
At first, I declared that
within these errors,
however small, lay the difference between brain and jewel, between human and machine, between love and its imitation. Eva, however, soon pointed out that it was absurd to make a radical, qualitative distinction on the basis of the sampling density; if the next model teacher sampled more neurons and halved the error rate, would
its
jewel then be ‘halfway’ between
‘human’ and ‘machine?’ In theory — and eventually, in practice — the error rate could be made smaller than any number I cared to name. Did I really believe that a discrepancy of one in a billion made any difference at all — when every human being was permanently losing thousands of neurons every day, by natural attrition?
She was right, of course, but I soon found another, more plausible, defence for my position. Living neurons, I argued, had far more internal structure than the crude optical switches that served the same function in the jewel’s so-called ‘neural net’. That neurons fired or did not fire reflected only one level of their behaviour; who knew what the subtleties of biochemistry — the quantum mechanics of the specific organic molecules involved — contributed to the nature of human consciousness? Copying the abstract neural topology wasn’t enough. Sure, the jewel could pass the fatuous Turing test — no outside observer could tell it from a human — but that didn’t prove that
being
a jewel felt the same as
being
human.
Eva asked, ‘Does that mean you’ll never switch? You’ll have your jewel removed? You’ll let yourself
die
when your brain starts to rot?’
‘Maybe,’ I said. ‘Better to die at ninety or a hundred than kill myself at thirty, and have some machine marching around, taking my place, pretending to be me.’
‘How do you know
I
haven’t switched?’ she asked, provocatively. ‘How do you know that I’m not just
“pretending to be me”?’
‘I know you haven’t switched,’ I said, smugly. ‘I just
know.’
‘How? I’d look the same. I’d talk the same. I’d act the same in every way. People are switching younger, these days.
So how do you know I haven’t?’
I turned on to my side towards her, and gazed into her eyes. ‘Telepathy. Magic. The communion of souls.’
My twelve-year-old self started snickering, but by then I knew exactly how to drive him away.
* * * *
At nineteen, although I was studying finance, I took an undergraduate philosophy unit. The Philosophy Department, however, apparently had nothing to say about the Ndoli Device, more commonly known as
‘the jewel’. (Ndoli had in fact called it ‘the
dual’,
but the accidental, homophonic nickname had stuck.) They talked about Plato and Descartes and Marx, they talked about St Augustine and — when feeling particularly modern and adventurous — Sartre, but if they’d heard of Godel, Turing, Hamsun or Kim, they refused to admit it. Out of sheer frustration, in an essay on Descartes I suggested that the notion of human consciousness as ‘software’ that could be ‘implemented’ equally well on an organic brain or an optical crystal was in fact a throwback to Cartesian dualism: for ‘software’ read ‘soul’. My tutor superimposed a neat, diagonal, luminous red line over each paragraph that dealt with this idea, and wrote in the margin (in vertical, bold-face, twenty-point Times, with a contemptuous two-hertz flash): irrelevant!
I quit philosophy and enrolled in a unit of optical crystal engineering for non-specialists. I learnt a lot of solid-state quantum mechanics. I learnt a lot of fascinating mathematics. I learnt that a neural net is a device used only for solving problems that are far too hard to be
understood.
A sufficiently flexible neural net can be configured by feedback to mimic almost any system — to produce the same patterns of output from the same patterns of input — but achieving this sheds no light whatsoever on the nature of the system being emulated.
‘Understanding,’ the lecturer told us, ‘is an overrated concept. Nobody really
understands
how a fertilised egg turns into a human. What should we do? Stop having children until ontogenesis can be described by a set of differential equations?’
I had to concede that she had a point there.
It was clear to me by then that nobody had the answers I craved — and I was hardly likely to come up with them myself; my intellectual skills were, at best, mediocre. It came down to a simple choice: I could waste time fretting about the mysteries of consciousness, or, like everybody else, I could stop worrying and get on with my life.
* * * *
When I married Daphne, at twenty-three, Eva was a distant memory, and so was any thought of the communion of souls. Daphne was thirty-one, an executive in the merchant bank that had hired me during my PhD, and everyone agreed that the marriage would benefit my career. What she got out of it, I was never quite sure. Maybe she actually liked me. We had an agreeable sex life, and we comforted each other when we were down, the way any kind-hearted person would comfort an animal in distress.
Daphne hadn’t switched. She put it off, month after month, inventing ever more ludicrous excuses, and I teased her as if I’d never had reservations of my own.
‘I’m afraid,’ she confessed one night. ‘What if
I die
when it happens — what if all that’s left is a robot, a puppet, a
thing?
I don’t want to
die.’
Talk like that made me squirm, but I hid my feelings. ‘Suppose you had a stroke,’ I said glibly, ‘which destroyed a small part of your brain. Suppose the doctors implanted a machine to take over the functions which that damaged region had performed. Would you still be “yourself’?’
‘Of course.’
‘Then if they did it twice, or ten times, or a thousand times—’
‘That doesn’t necessarily follow.’
‘Oh? At what magic percentage, then, would you stop being you ?
She glared at me. ‘All the old clichéd arguments—’
‘Fault them, then, if they’re so old and clichéd.’
She started to cry. ‘I don’t have to. Fuck you! I’m scared to death, and you don’t give a shit!’
I took her in my arms. ‘Sssh. I’m sorry. But
everyone
does it sooner or later. You mustn’t be afraid. I’m here. I love you.’ The words might have been a recording, triggered automatically by the sight of her tears.
‘Will you do it? With me?’
I went cold. ‘What?’
‘Have the operation, on the same day? Switch when I switch?’
Lots of couples did that. Like my parents. Sometimes, no doubt, it was a matter of love, commitment, sharing. Other times, I’m sure, it was more a matter of neither partner wishing to be an unswitched person living with a jewel-head.
I was silent for a while, then I said, ‘Sure.’
In the months that followed, all of Daphne’s fears — which I’d mocked as ‘childish’ and ‘superstitious’
— rapidly began to make perfect sense, and my own ‘rational’ arguments came to sound abstract and hollow. I backed out at the last minute; I refused the anaesthetic, and fled the hospital.
Daphne went ahead, not knowing I had abandoned her.
I never saw her again. I couldn’t face her; I quit my job and left town for a year, sickened by my cowardice and betrayal — but at the same time euphoric that I had
escaped.
She brought a suit against me, but then dropped it a few days later, and agreed, through her lawyers, to an uncomplicated divorce. Before the divorce came through, she sent me a brief letter:
There was nothing to fear, after all. I’m exactly the person I’ve always been. Putting it off was
insane; now that I’ve taken the leap of faith, I couldn’t be more at ease.
Your loving robot wife,
Daphne
* * * *
By the time I was twenty-eight, almost everyone I knew had switched. All my friends from university had done it. Colleagues at my new job, as young as twenty-one, had done it. Eva, I heard through a friend of a friend, had done it six years before.
The longer I delayed, the harder the decision became. I could talk to a thousand people who had switched, I could grill my closest friends for hours about their childhood memories and their most private thoughts, but however compelling their words, I knew that the Ndoli Device had spent decades buried in their heads, learning to fake exactly this kind of behaviour.
Of course, I always acknowledged that it was equally impossible to be
certain
that even another
unswitched
person had an inner life in any way the same as my own — but it didn’t seem unreasonable to be more inclined to give the benefit of the doubt to people whose skulls hadn’t yet been scraped out with a curette.
I drifted apart from my friends, I stopped searching for a lover. I took to working at home (I put in longer hours and my productivity rose, so the company didn’t mind at all). I couldn’t bear to be with people whose humanity I doubted.
I wasn’t by any means unique. Once I started looking, I found dozens of organisations exclusively for people who hadn’t switched, ranging from a social club that might as easily have been for divorcees, to a paranoid, paramilitary ‘resistance front’, who thought they were living out
Invasion of the Body
Snatchers.
Even the members of the social club, though, struck me as extremely maladjusted; many of them shared my concerns, almost precisely, but my own ideas from other lips sounded obsessive and ill-conceived. I was briefly involved with an unswitched woman in her early forties, but all we ever talked about was our fear of switching. It was masochistic, it was suffocating, it was insane.