A clock ticks. Somewhere, a baby cries. You’re in an oddly abstract space, all planes and verticals. It reminds you of a library. You don’t remember ever being in a library. You remember nothing but the sudden unprovoked shove in the small of your back, and the precipitate drop. A split-second glimpse of shining railway tracks, wooden sleepers, the ingenious mechanism of points.
Then oblivion.
Now this.
Even here, in this Platonic afterlife, you’re fat. You always will be fat. It defines you, eternally. You’re the Fat Man. It seems unfair. You don’t even remember eating.
Perspiring, thighs chafing in your ill-fitting suit, you set off in search of the crying baby. Your quest takes you around a corner, and at once you are in a library. It’s no improvement: the maze of shelving seems endless. You take down a book, and find page after page of random letters. The next you open is blank, except for one page with a single flyspeck of comma.
You put the book back in its place and plod on. The crying diminishes. You cock your head, turn, walk to another corner and triangulate. Off you go again, with more confidence.
Around the next corner, at eye level, you meet a pair of eyes.
The eyes are connected to a brain, which hangs unsupported in mid-air. The brain is connected to a tiny, tinny-looking audio device where its chin would be if it had a skull.
“Hello,” says the brain.
“Hello,” you say. You stick out your hand, then withdraw it and wipe your palm on your thigh. Hurriedly, you introduce yourself.
“I’m the Fat Man, from” – it dawns on you – “the Trolley Problem.”
“Pleased to meet you,” the speaker crackles. “I’m the Brain.”
“Yes?”
“A Boltzmann brain,” it elaborates. “A conscious human brain formed by random molecular motion in the depths of space.”
“That seems improbable.”
“Highly improbable!” the Brain agrees. “But given enough space, matter and time, inevitable – unfortunately for me.” It rotates, looking around. “We seem to be in the Library of Babel, the useless library of all possible books.” Its rotation brings its eyes back around to you, and stops. “I keep wishing I could blink.”
You shrug. “Sorry, I can’t help.”
The Brain laughs. “Count yourself lucky you’re not from the thought experiment about organ donation.”
You shudder.
“Well,” says the Brain, briskly, “let’s see if we can find baby Hitler and calm him down. All this crying is getting on my nerves.”
The Brain zooms away, and you hurry after it, your thoughts catching up at the same time. Information comes to you when you need it, yet you have no memory of any life before this. It’s like you’re...
But you’ve caught up.
“That baby is Hitler?”
“Yes,” says the Brain, as if over its shoulder. “Time travellers keep trying to kill him. They always fail, of course, but it’s most unsettling for the child. Frankly, I fear for his future mental stability.”
From the next aisle comes the sound of footsteps, and a woman’s voice:
“Loud and clear, Bob. Loud and clear.”
You sidestep between bookcases to intercept the clicking footsteps. The woman halts. She is wearing a dark blue shift-dress and black high-heeled shoes. Over her neat hairdo sits a set of headphones with a mike in front of her mouth. She looks at you with disdain and at the Brain with distaste.
You introduce yourselves. She’s Alice. She keeps talking quietly to Bob, warning him against some third-party eavesdropper, Charlie. Otherwise, she’s not very communicative.
Soon the three of you find the baby crying in a carved wooden cradle in a canyon of books. You look at it helplessly, then at Alice. She shoots you a baleful glare, picks up the child, and strokes and coos and pats his back. Hitler pukes on her shoulder. Then he stops bawling, but keeps looking around. His crumpled little face glowers with wary suspicion.
Once the baby’s hushed, the sound that predominates is the ticking. You listen intently, trying to detect its source. Suddenly the ticking is interrupted by a scream, followed by sobs.
“Jeez!” says Alice. “What now?”
“It’s the Ticking Bomb Scenario,” says the Brain. “Some poor devil is being tortured to reveal its location.”
“We have to stop that!” you cry.
“Why?” asks Alice, coldly. “Do you value some terrorist’s comfort over the lives of innocents?”
“I was innocent,” you point out. “Nobody asked my opinion before shoving me to certain death.”
You and Alice glare at each other.
“Sounds like you’re a Kantian and Alice is a utilitarian,” muses the Brain. “The dignity of the individual versus the greatest good of the greatest number.”
Stand-off.
“I know!” says the Brain, brightly. “Let’s find the Ticking Bomb and turn it off ourselves!”
“Sounds like a plan,” says Alice.
The Brain rises high above the shelves, almost out of sight. It roams, rotating, then swoops back.
“Found it!” it says. “Thirty-two minutes to go before it explodes.”
“Will we have time?” you ask.
“If we hurry.”
Hurry, you do. Alice’s heels go click-click-click. Baby Hitler bounces up and down in her reluctant embrace. You’re almost out of breath. The Brain darts ahead, a gruesome will-o’-the-wisp guiding you onwards.
You arrive at a wider space amid the shelving, with a table in the middle. In the middle of the table is a box, on which is mounted some kind of apparatus. A man in a white coat is observing the box. Behind the man is another man, observing the man and the box. Behind that man stands... well, you know how it goes.
From inside the box comes the sound of a cat mewling, a protest louder and more plaintive even than that of Baby Hitler.
“Should we –?” you ask.
“No,” says the Brain. “It would just add another layer of decoherence to the wave function.”
“Damn right,” says Alice. “No way am I going back for that goddamn cat.”
You all hurry on, leaving Schrödinger’s Cat, Schrödinger himself, Wigner, Wigner’s friend and all the others to their indefinite fate. The Brain leads you around a corner and into an aisle facing a glass wall. The light is ruddy. You spare a glance outside. To the horizon stretch waste dumps, some burning. On them crawl endless human figures, salvaging junk, grubbing subsistence from garbage.
“Is that Hell?” asks Alice, sounding horrified.
“No,” the Brain calls back. “It’s trillions of people living lives barely worth living! But it’s a better situation than mere billions of people living lives well worth living, wouldn’t you agree?”
“No,” says Alice. “I wouldn’t.”
“Nor I,” you say.
“Too bad!” says the Brain. “The reasoning is rigorous. Your revulsion is mistaken, but understandable. It’s not called the Repugnant Conclusion for nothing, you know.”
You have no breath to spare for argument. Another ten minutes’ jogging brings you all in front of the Ticking Bomb. The simple timer, now counting down from twelve minutes, is attached to a large cylindrical device labelled ‘10 kilotons’.
“Oh!” says the Brain. “It’s an atomic bomb! Does that change our views on the morality of torture?”
“No,” say you and Alice at the same moment. Baby Hitler’s eyes widen and his face brightens, but he says nothing.
Alice reaches over and turns the timer back to one hour. The ticking resumes.
“Now we have time to think,” she says.
“It’s interesting to reflect,” says the Brain, “that somewhere in this library is a book containing a complete system of self-evident moral philosophy that answers all our questions. Formed out of random letters, just as I am formed out of random molecules.”
“Along with its refutation?” says Alice.
“Point,” says the Brain.
“One of us must stay here,” you say, “and keep turning the clock back, while the others go and find the torture chamber before too many more fingernails are extracted. And then – “
“And then what?” asks Alice. “How does that help all the poor people outside?”
“No,” you say, “but – “
“Have you noticed how our memories work? Doesn’t it strike you as odd? Try drawing something at random.”
You try to think of something. Nothing comes to mind..
“What?” you say. “I can’t think of anything I’m not thinking about.”
“Tree,” says Alice. You’ve never heard the word before. You sketch a tree.
“See?” says Alice. “That’s not how human memories work. That’s how computer memories work, as I’m sure the Brain can confirm.”
“Yes,” says the Brain. “And?”
“We aren’t human minds,” says Alice. “We’re abstractions of the subjects and victims of thought experiments. This isn’t a physical space, and I doubt that it’s some kind of afterlife, given that none of us had lives. The overwhelming probability is that we’re in a simulation.”
“Ah,” you say. “But –”
“Yes,” says Alice. “What monsters the creators of such a simulation must be!”
You and Alice look out of the window at the hellish landscape, and at each other.
“We must put a stop to this,” you say.
Alice nods. You reach for the timer at the same moment.
“Wait!” cries the Brain.
Too late.
Zero.
What the Brain was about to tell you is that there are worse possibilities than being in a simulation. The worst possibility is that this thought experiment is simply a possibility, but a logical one. From inside a logical possibility, there is no way to distinguish it from actuality. And a logical possibility can’t be made or unmade by omnipotence itself, let alone by a ten-kiloton atomic bomb.
What the Brain doesn’t know, and couldn’t possibly tell you, is that there is a greater possibility: that somewhere, somehow, all the victims of all the logical possibilities including those that exist in what we laughingly call actuality can be saved, can be liberated, can be redeemed; that their suffering can be expunged as though it had never been; and that, however impossible that great, all-encompassing thought experiment may seem, or indeed be, it is nevertheless something for which you are doomed to strive, and to seek over and over again until you find it.
A clock ticks. Somewhere, a baby cries. You’re in an oddly abstract space, all planes and verticals. It reminds you of a library.