Read Harry Potter and the Methods of Rationality Online
Authors: Eliezer Yudkowsky
“Mum,” Harry said into the unnerving silence, “I’m going to test the hypothesis. According to your theory, how do I send an owl to Hogwarts?”
His mother turned from the kitchen sink to stare at him, looking shocked. “I - I don’t know, I think you just have to own a magic owl.”
That should’ve sounded highly suspicious,
oh, so there’s no way to test your theory then,
but the peculiar certainty in Harry seemed willing to stick its neck out even further.
“Well, the letter got here somehow,” Harry said, “so I’ll just wave it around outside and call ‘letter for Hogwarts!’ and see if an owl picks it up. Dad, do you want to come and watch?”
His father shook his head minutely and kept on reading.
Of course,
Harry thought to himself. Magic was a disgraceful thing that only stupid people believed in; if his father went so far as to
test
the hypothesis, or even
watch
it being tested, that would feel like
associating
himself with that…
Only as Harry stumped out the back door, into the back garden, did it occur to him that if an owl
did
come down and snatch the letter, he was going to have some trouble telling Dad about it.
But - well - that can’t
really
happen, can it? No matter what my brain seems to believe. If an owl really comes down and grabs this envelope, I’m going to have worries a lot more important than what Dad thinks.
Harry took a deep breath, and raised the envelope into the air.
He swallowed.
Calling out
Letter for Hogwarts!
while holding an envelope high in the air in the middle of your own back garden was… actually pretty embarrassing, now that he thought about it.
No. I’m better than Dad. I will use the scientific method even if it makes me feel stupid.
“Letter -” Harry said, but it actually came out as more of a whispered croak.
Harry steeled his will, and shouted into the empty sky, “
Letter for Hogwarts! Can I get an owl?
”
“Harry?” asked a bemused woman’s voice, one of the neighbours.
Harry pulled down his hand like it was on fire and hid the envelope behind his back like it was drug money. His whole face was hot with shame.
An old woman’s face peered out from above the neighbouring fence, grizzled grey hair escaping from her hairnet. Mrs. Figg, the occasional babysitter. “What are you doing, Harry?”
“Nothing,” Harry said in a strangled voice. “Just - testing a really silly theory -”
“Did you get your acceptance letter from Hogwarts?”
Harry froze in place
.
“Yes,” Harry’s lips said a little while later. “I got a letter from Hogwarts. They say they want my owl by the 31st of July, but -”
“But you don’t
have
an owl. Poor dear! I can’t imagine
what
someone must have been thinking, sending you just the standard letter.”
A wrinkled arm stretched out over the fence, and opened an expectant hand. Hardly even thinking at this point, Harry gave over his envelope.
“Just leave it to me, dear,” said Mrs. Figg, “and in a jiffy or two I’ll have someone over.”
And her face disappeared from over the fence.
There was a long silence in the garden.
Then a boy’s voice said, calmly and quietly, “What.”
#include “stddisclaimer.h”
“Of course it was my fault. There’s no one else here who could be responsible for anything.”
“Now, just to be clear,” Harry said, “if the professor does levitate you, Dad, when you know you haven’t been attached to any wires, that’s going to be sufficient evidence. You’re not going to turn around and say that it’s a magician’s trick. That wouldn’t be fair play. If you feel that way, you should say so
now
, and we can figure out a different experiment instead.”
Harry’s father, Professor Michael Verres-Evans, rolled his eyes. “Yes, Harry.”
“And you, Mum, your theory says that the professor should be able to do this, and if that doesn’t happen, you’ll admit you’re mistaken. Nothing about how magic doesn’t work when people are sceptical of it, or anything like that.”
Deputy Headmistress Minerva McGonagall was watching Harry with a bemused expression. She looked quite witchy in her black robes and pointed hat, but when she spoke she sounded formal and Scottish, which didn’t go together with the look at all. At first glance she looked like someone who ought to cackle and put babies into cauldrons, but the whole effect was ruined as soon as she opened her mouth. “Is that sufficient, Mr. Potter?” she said. “Shall I go ahead and demonstrate?”
“
Sufficient?
Probably not,” Harry said. “But at least it will
help.
Go ahead, Deputy Headmistress.”
“Just Professor will do,” said she, and then, “
Wingardium Leviosa
.”
Harry looked at his father.
“Huh,” Harry said.
His father looked back at him. “Huh,” his father echoed.
Then Professor Verres-Evans looked back at Professor McGonagall. “All right, you can put me down now.”
His father was lowered carefully to the ground.
Harry ruffled a hand through his own hair. Maybe it was just that strange part of him which had
already
been convinced, but… “That’s a bit of an anticlimax,” Harry said. “You’d think there’d be some kind of more dramatic mental event associated with updating on an observation of infinitesimal probability -” Harry stopped himself. Mum, the witch, and even his Dad were giving him
that look
again. “I mean, with finding out that everything I believe is false.”
Seriously, it should have been more dramatic. His brain ought to have been flushing its entire current stock of hypotheses about the universe, none of which allowed this to happen. But instead his brain just seemed to be going,
All right, I saw the Hogwarts Professor wave her wand and make your father rise into the air, now what?
The witch-lady was smiling benevolently upon them, looking quite amused. “Would you like a further demonstration, Mr. Potter?”
“You don’t have to,” Harry said. “We’ve performed a definitive experiment. But…” Harry hesitated. He couldn’t help himself. Actually, under the circumstances, he
shouldn’t
be helping himself. It was right and proper to be curious. “What else
can
you do?”
Professor McGonagall turned into a cat.
Harry scrambled back unthinkingly, backpedalling so fast that he tripped over a stray stack of books and landed hard on his bottom with a
thwack.
His hands came down to catch himself without quite reaching properly, and there was a warning twinge in his shoulder as the weight came down unbraced.
At once the small tabby cat morphed back up into a robed woman. “I’m sorry, Mr. Potter,” said the witch, sounding sincere, though the corners of her lips were twitching upwards. “I should have warned you.”
Harry was breathing in short gasps. His voice came out choked.
“You can’t DO that!”
“It’s only a Transfiguration,” said Professor McGonagall. “An Animagus transformation, to be exact.”
“You turned into a cat! A
SMALL
cat! You violated Conservation of Energy! That’s not just an arbitrary rule, it’s implied by the form of the quantum Hamiltonian! Rejecting it destroys unitarity and then you get FTL signalling! And cats are
COMPLICATED!
A human mind can’t just visualise a whole cat’s anatomy and, and all the cat biochemistry, and what about the
neurology?
How can you go on
thinking
using a cat-sized brain?”
Professor McGonagall’s lips were twitching harder now. “Magic.”
“Magic
isn’t enough
to do that! You’d have to be a god!”
Professor McGonagall blinked. “That’s the first time I’ve ever been called
that.
”
A blur was coming over Harry’s vision, as his brain started to comprehend what had just broken. The whole idea of a unified universe with mathematically regular laws, that was what had been flushed down the toilet; the whole notion of
physics
. Three thousand years of resolving big complicated things into smaller pieces, discovering that the music of the planets was the same tune as a falling apple, finding that the true laws were perfectly universal and had no exceptions anywhere and took the form of simple maths governing the smallest parts,
not to mention
that the mind was the brain and the brain was made of neurons, a brain was what a person
was
-
And then a woman turned into a cat, so much for all that.
A hundred questions fought for priority over Harry’s lips and the winner poured out: “And, and what kind of incantation is
Wingardium Leviosa?
Who invents the words to these spells, nursery schoolers?”
“That will do, Mr. Potter,” Professor McGonagall said crisply, though her eyes shone with suppressed amusement. “If you wish to learn about magic, I suggest that we finalise the paperwork so that you can go to Hogwarts.”
“Right,” Harry said, somewhat dazed. He pulled his thoughts together. The March of Reason would just have to start over, that was all; they still had the experimental method and that was the important thing. “How do I get to Hogwarts, then?”
A choked laugh escaped Professor McGonagall, as if extracted from her by tweezers.
“Hold on a moment, Harry,” his father said. “Remember why you haven’t been going to school up until now? What about your condition?”
Professor McGonagall spun to face Michael. “His condition? What’s this?”
“I don’t sleep right,” Harry said. He waved his hands helplessly. “My sleep cycle is twenty-six hours long, I always go to sleep two hours later, every day. I can’t fall asleep any earlier than that, and then the next day I go to sleep two hours later than
that.
10PM, 12AM, 2AM, 4AM, until it goes around the clock. Even if I try to wake up early, it makes no difference and I’m a wreck that whole day. That’s why I haven’t been going to a normal school up until now.”
“One of the reasons,” said his mother. Harry shot her a glare.
McGonagall gave a long
hmmmmm.
“I can’t recall hearing about such a condition before…” she said slowly. “I’ll check with Madam Pomfrey to see if she knows any remedies.” Then her face brightened. “No, I’m sure this won’t be a problem - I’ll find a solution in time. Now,” and her gaze sharpened again, “what are these
other
reasons?”
Harry sent his parents a glare. “I am a conscientious objector to child conscription, on grounds that I should not have to suffer for a disintegrating school system’s failure to provide teachers or study materials of even minimally adequate quality.”
Both of Harry’s parents howled with laughter at that, like they thought it was all a big joke. “Oh,” said Harry’s father, eyes bright, “is
that
why you bit a maths teacher in third year.”
“
She didn’t know what a logarithm was!
”
“Of course,” seconded Harry’s mother. “Biting her was a very mature response to that.”
Harry’s father nodded. “A well-considered policy for addressing the problem of teachers who don’t understand logarithms.”
“I was
seven years old!
How long are you going to keep on bringing that up?”
“I know,” said his mother sympathetically, “you bite
one
maths teacher and they never let you forget it, do they?”
Harry turned to Professor McGonagall. “There! You see what I have to deal with?”
“Excuse me,” said Petunia, and fled through the backdoor into the garden, from which her screams of laughter were clearly audible.
“There, ah, there,” Professor McGonagall seemed to be having trouble speaking for some reason, “there is to be no biting of teachers at Hogwarts, is that quite clear, Mr. Potter?”
Harry scowled at her. “Fine, I won’t bite anyone who doesn’t bite me first.”
Professor Michael Verres-Evans also had to leave the room briefly upon hearing that.
“Well,” Professor McGonagall sighed, after Harry’s parents had composed themselves and returned. “Well. I think, under the circumstances, that I should avoid taking you to purchase your study materials until a day or two before school begins.”
“What? Why? The other children already know magic, don’t they? I have to start catching up right away!”
“Rest assured, Mr. Potter,” replied Professor McGonagall, “Hogwarts is quite capable of teaching the basics. And I suspect, Mr. Potter, that if I leave you alone for two months with your schoolbooks, even without a wand, I will return to this house only to find a crater billowing purple smoke, a depopulated city surrounding it and a plague of flaming zebras terrorising what remains of England.”
Harry’s mother and father nodded in perfect unison.
“
Mum! Dad!
”
If J. K. Rowling asks you about this story, you know nothing.
“But then the question is - who?”
“Good Lord,” said the barman, peering at Harry, “is this - can this be -?”
Harry leaned towards the bar of the Leaky Cauldron as best he could, though it came up to somewhere around the tips of his eyebrows. A question like
that
deserved his very best.
“Am I - could I be - maybe - you never know - if I’m
not
- but then the question is -
who?
”
“Bless my soul,” whispered the old barman. “Harry Potter… what an honour.”
Harry blinked, then rallied. “Well, yes, you’re quite perceptive; most people don’t realise that so quickly -”
“That’s enough,” Professor McGonagall said. Her hand tightened on Harry’s shoulder. “Don’t pester the boy, Tom, he’s new to all this.”
“But it is him?” quavered an old woman. “It’s Harry Potter?” With a scraping sound, she got up from her chair.
“Doris -” McGonagall said warningly. The glare she shot around the room should have been enough to intimidate anyone.
“I only want to shake his hand,” the woman whispered. She bent low and stuck out a wrinkled hand, which Harry, feeling confused and more uncomfortable than he ever had in his life, carefully shook. Tears fell from the woman’s eyes onto their clasped hands. “My granson was an Auror,” she whispered to him. “Died in seventy-nine. Thank you, Harry Potter. Thank heavens for you.”
“You’re welcome,” Harry said automatically, and then he turned his head and shot Professor McGonagall a frightened, pleading look.
Professor McGonagall slammed her foot down just as the general rush was about to start. It made a noise that gave Harry a new referent for the phrase “Crack of Doom”, and everyone froze in place.
“We’re in a hurry,” Professor McGonagall said in a voice that sounded perfectly, utterly normal.
They left the bar without any trouble.
“Professor?” Harry said, once they were in the courtyard. He had meant to ask what was going on, but oddly found himself asking an entirely different question instead. “Who was that pale man, by the corner? The man with the twitching eye?”
“Hm?” said Professor McGonagall, sounding a bit surprised; perhaps she hadn’t expected that question either. “That was Professor Quirinus Quirrell. He’ll be teaching Defence Against the Dark Arts this year at Hogwarts.”
“I had the strangest feeling that I knew him…” Harry rubbed his forehead. “And that I shouldn’t ought to shake his hand.” Like meeting someone who had been a friend, once, before something went drastically wrong… that wasn’t really it at all, but Harry couldn’t find words. “And what
was…
all of that?”
Professor McGonagall was giving him an odd glance. “Mr. Potter… do you know… how
much
have you been told… about how your parents died?”
Harry returned a steady look. “My parents are alive and well, and they always refused to talk about how my
genetic
parents died. From which I infer that it wasn’t good.”
“An admirable loyalty,” said Professor McGonagall. Her voice went low. “Though it hurts a little to hear you say it like that. Lily and James were friends of mine.”
Harry looked away, suddenly ashamed. “I’m sorry,” he said in a small voice. “But I
have
a Mum and Dad. And I know that I’d just make myself unhappy by comparing that reality to… something perfect that I built up in my imagination.”
“That is amazingly wise of you,” Professor McGonagall said quietly. “But your
genetic
parents died very well indeed, protecting you.”
Protecting me?
Something strange clutched at Harry’s heart. “What…
did
happen?”
Professor McGonagall sighed. Her wand tapped Harry’s forehead, and his vision blurred for a moment. “Something of a disguise,” she said, “so that this doesn’t happen again, not until you’re ready.” Then her wand licked out again, and tapped three times on a brick wall…
…which hollowed into a hole, and dilated and expanded and shivered into a huge archway, revealing a long row of shops with signs advertising cauldrons and dragon livers.
Harry didn’t blink. It wasn’t like anyone was turning into a cat.
And they walked forwards, together, into the wizarding world.
There were merchants hawking Bounce Boots (“Made with real Flubber!”) and “Knives +3! Forks +2! Spoons with a +4 bonus!” There were goggles that would turn anything you looked at green, and a lineup of comfy armchairs with ejection seats for emergencies.
Harry’s head kept rotating, rotating like it was trying to wind itself off his neck. It was like walking through the magical items section of an
Advanced Dungeons and Dragons
rulebook (he didn’t play the game, but he did enjoy reading the rulebooks). Harry desperately didn’t want to miss a single item for sale, in case it was one of the three you needed to complete the cycle of infinite
wish
spells.
Then Harry spotted something that made him, entirely without thinking, veer off from the Deputy Headmistress and start heading straight into the shop, a front of blue bricks with bronze-metal trim. He was brought back to reality only when Professor McGonagall stepped right in front of him.
“Mr. Potter?” she said.
Harry blinked, then realised what he’d just done. “I’m sorry! I forgot for a moment that I was with you instead of my family.” Harry gestured at the shop window, which displayed fiery letters that shone piercingly bright and yet remote, spelling out
Bigbam’s Brilliant Books
. “When you walk past a bookshop you haven’t visited before, you have to go in and look around. That’s the family rule.”
“That is the most Ravenclaw thing I have ever heard.”
“What?”
“Nothing. Mr. Potter, our first step is to visit Gringotts, the bank of the wizarding world. Your
genetic
family vault is there, with the inheritance your
genetic
parents left you, and you’ll need money for school supplies.” She sighed. “And, I suppose, a certain amount of spending money for books could be excused as well. Though you might want to hold off for a time. Hogwarts has quite a large library on magical subjects. And the tower in which, I strongly suspect, you will be living, has a more broad-ranging library of its own. Any book you bought now would probably be a duplicate.”
Harry nodded, and they walked on.
“Don’t get me wrong, it’s a
great
distraction,” Harry said as his head kept swivelling, “probably the best distraction anyone has ever tried on me, but don’t think I’ve forgotten about our pending discussion.”
Professor McGonagall sighed. “Your parents - or your mother at any rate - may have been very wise not to tell you.”
“So you wish that I could continue in blissful ignorance? There is a certain flaw in that plan, Professor McGonagall.”
“I suppose it would be rather pointless,” the witch said tightly, “when anyone on the street could tell you the story. Very well.”
And she told him of He-Who-Must-Not-Be-Named, the Dark Lord, Voldemort.
“Voldemort?” Harry whispered. It should have been funny, but it wasn’t. The name burned with a cold feeling, ruthlessness, diamond clarity, a hammer of pure titanium descending upon an anvil of yielding flesh. A chill swept over Harry even as he pronounced the word, and he resolved then and there to use safer terms like You-Know-Who.
The Dark Lord had raged upon wizarding Britain like a wilding wolf, tearing and rending at the fabric of their everyday lives. Other countries had wrung their hands but hesitated to intervene, whether out of apathetic selfishness or simple fear, for whichever was first among them to oppose the Dark Lord, their peace would be the next target of his terror.
(
The bystander effect,
thought Harry, thinking of Latane and Darley’s experiment which had shown that you were more likely to get help if you had an epileptic fit in front of one person than in front of three.
Diffusion of responsibility, everyone hoping that someone else would go first.
)
The Death Eaters had followed in the Dark Lord’s wake and in his vanguard, carrion vultures to pick at wounds, or snakes to bite and weaken. The Death Eaters were not as terrible as the Dark Lord, but they were terrible, and they were many. And the Death Eaters wielded more than wands; there was wealth within those masked ranks, and political power, and secrets held in blackmail, to paralyse a society trying to protect itself.
An old and respected journalist, Yermy Wibble, called for increased taxes and conscription. He shouted that it was absurd for the many to cower in fear of the few. His skin, only his skin, had been found nailed to the newsroom wall that next morning, next to the skins of his wife and two daughters. Everyone wished for something more to be done, and no one dared take the lead to propose it. Whoever stood out the most became the next example.
Until the names of James and Lily Potter rose to the top of that list.
And those two might have died with their wands in their hands and not regretted their choices, for they
were
heroes; but for that they had an infant child, their son, Harry Potter.
Tears were coming into Harry’s eyes. He wiped them away in anger or maybe desperation,
I didn’t know those people, not really, they aren’t my parents
now,
it would be pointless to feel so sad for them -
When Harry was done sobbing into the witch’s robes, he looked up, and felt a little bit better to see tears in Professor McGonagall’s eyes as well.
“So what happened?” Harry said, his voice trembling.
“The Dark Lord came to Godric’s Hollow,” Professor McGonagall said in a whisper. “You should have been hidden, but you were betrayed. The Dark Lord killed James, and he killed Lily, and he came in the end to you, to your cot. He cast the Killing Curse at you, and that was where it ended. The Killing Curse is formed of pure hate, and strikes directly at the soul, severing it from the body. It cannot be blocked, and whomever it strikes, they die. But you survived. You are the only person ever to survive. The Killing Curse rebounded and struck the Dark Lord, leaving only the burnt hulk of his body and a scar upon your forehead. That was the end of the terror, and we were free. That, Harry Potter, is why people want to see the scar on your forehead, and why they want to shake your hand.”
The storm of weeping that had washed through Harry had used up all his tears; he could not cry again, he was done.
(And somewhere in the back of his mind was a small, small note of confusion, a sense of something wrong about that story; and it should have been a part of Harry’s art to notice that tiny note, but he was distracted. For it is a sad rule that whenever you are most in need of your art as a rationalist, that is when you are most likely to forget it.)
Harry detached himself from Professor McGonagall’s side. “I’ll - have to think about this,” he said, trying to keep his voice under control. He stared at his shoes. “Um. You can go ahead and call them my parents, if you want, you don’t have to say ‘genetic parents’ or anything. I guess there’s no reason I can’t have two mothers and two fathers.”
There was no sound from Professor McGonagall.
And they walked together in silence, until they came before a great white building with vast bronze doors, and carven words above saying
Gringotts Bank.