Harry Potter and the Methods of Rationality

by Eliezer Yudkowsky

  Dear Father, Draco wrote.

  And then he stopped.

  Ink slowly dripped from his quill, staining the parchment near the words.

  Draco wasn't stupid. He was young, but his tutors had trained him well. Draco knew that Potter probably felt a lot more sympathy towards Dumbledore's faction than Potter was letting on... though Draco did think Potter could be tempted. But it was crystal clear that Potter was trying to tempt Draco just as Draco was trying to tempt him.

  And it was also clear that Potter was brilliant, and a whole lot more than just slightly mad, and playing a vast game that Potter himself mostly didn't understand, improvised at top speed with the subtlety of a rampaging nundu. But Potter had managed to choose a tactic that Draco couldn't just walk away from. He had offered Draco a part of his own power, gambling that Draco couldn't use it without becoming more like him. His father had called this an advanced technique, and had warned Draco that it often didn't work.

  Draco knew he hadn't understood everything that had happened... but Potter had offered him the chance to play and right now it was his. And if he blurted the whole thing out, it would become Father's.

  In the end it was as simple as that. The lesser techniques require the unawareness of the target, or at least their uncertainty. Flattery has to be plausibly disguised as admiration. ("You should have been in Slytherin" is an old classic, highly effective on a certain type of person who isn't expecting it, and if it works you can repeat it.) But when you find someone's ultimate lever it doesn't matter if they know you know. Potter, in his mad rush, had guessed a key to Draco's soul. And if Draco knew that Potter knew it - even if it had been an obvious sort of guess - that didn't change anything.

  So now, for the first time in his life, he had real secrets to keep. He was playing his own game. There was an obscure pain to it, but he knew that Father would be proud, and that made it all right.

  Leaving the ink drippings in place - there was a message there, and one that his father would understand, for they had played the game of subtleties more than once - Draco wrote out the one question that really had gnawed at him about the whole affair, the part that it seemed he ought to understand, but he didn't, not at all.

  Dear Father:

  Suppose I told you that I met a student at Hogwarts, not already part of our circle of acquaintances, who called you a 'flawless instrument of death' and said that I was your 'one weak point'. What would you say about him?

  It didn't take long after that for the family owl to bring the reply.

  My beloved son:

  I would say that you had been so fortunate as to meet someone who enjoys the intimate confidence of our friend and valuable ally, Severus Snape.

  Draco stared at the letter for a while, and finally threw it into the fire.

  Chapter 8: Positive Bias

  All these worlds are J. K. Rowling's, except Europa. Attempt no fanfics there.

  One alert reviewer asked whether, if Luna is a seer, that means this is going to be an HPDM bottom!Draco mpreg fic. I regret that FFN does not allow me any larger font size in which to say NO. It honestly hadn't occurred to me that Luna might be a real seer - I'll have to decide whether to run with that or not - but I think we can all safely assume that if Luna is a seer, she said something about "light planting a seed in darkness", and Xenophilius, as always, interpreted this in rather the wrong way.

  "Allow me to warn you that challenging my ingenuity is a dangerous sort of project, and may tend to make your life a lot more surreal."

  No one had asked for help, that was the problem. They'd just gone around talking, eating, or staring into the air while their parents exchanged gossip. For whatever odd reason, no one had been sitting down reading a book, which meant she couldn't just sit down next to them and take out her own book. And even when she'd boldly taken the initiative by sitting down and continuing her third read-through of Hogwarts: A History, no one had seemed inclined to sit down next to her.

  Aside from helping people with their homework, or anything else they needed, she really didn't know how to meet people. She didn't feel like she was a shy person. She thought of herself as a take-charge sort of girl. And yet, somehow, if there wasn't some request along the lines of "I can't remember how to do long division" then it was just too awkward to go up to someone and say... what? She'd never been able to figure out what. And there didn't seem to be a standard information sheet, which was ridiculous. The whole business of meeting people had never seemed sensible to her. Why did she have to take all the responsibility herself when there were two people involved? Why didn't adults ever help? She wished some other girl would just walk up to her and say, "Hermione, the teacher told me to be friends with you."

  But let it be quite clear that Hermione Granger, sitting alone on the first day of school in one of the few compartments that had been empty, in the last carriage of the train, with the compartment door left open just in case anyone for any reason wanted to talk to her, was not sad, lonely, gloomy, depressed, despairing, or obsessing about her problems. She was, rather, rereading Hogwarts: A History for the third time and quite enjoying it, with only a faint tinge of annoyance in the back of her mind at the general unreasonableness of the world.

  There was the sound of an inter-train door opening, and then footsteps and an odd slithering sound coming down the hallway of the train. Hermione laid aside Hogwarts: A History and stood up and stuck her head outside - just in case someone needed help - and saw a young boy in a wizard's dress robes, probably first or second year going by his height, and looking quite silly with a scarf wrapped around his head. A small trunk stood on the floor next to him. Even as she saw him, he knocked on the door of another, closed compartment, and he said in a voice only slightly muffled by the scarf, "Excuse me, can I ask a quick question?"

  She didn't hear the answer from inside the compartment, but after the boy opened the door, she did think she heard him say - unless she'd somehow misheard - "Does anyone here know the six quarks or where I can find a first-year girl named Hermione Granger?"

  After the boy had closed that compartment door, Hermione said, "Can I help you with something?"

  The scarfed face turned to look at her, and the voice said, "Not unless you can name the six quarks or tell me where to find Hermione Granger."

  "Up, down, strange, charm, truth, beauty, and why are you looking for her?"

  It was hard to tell from this distance, but she thought she saw the boy grin widely under his scarf. "Ah, so you're a first-year girl named Hermione Granger," said that young, muffled voice. "On the train to Hogwarts, no less." The boy started to walk towards her and her compartment, and his trunk slithered along after him. "Technically, all I needed to do was look for you, but it seems likely that I'm meant to talk to you or invite you to join my party or get a key magical item from you or find out that Hogwarts was built over the ruins of an ancient temple or something. PC or NPC, that is the question?"

  Hermione opened her mouth to reply to this, but then she couldn't think of any possible reply to... whatever it was she'd just heard, even as the boy walked over to her, looked inside the compartment, nodded with satisfaction, and sat down on the bench across from her own. His trunk scurried in after him, grew to three times its former diameter and snuggled up next to her own in an oddly disturbing fashion.

  "Please, have a seat," said the boy, "and do please close the door behind you, if you would. Don't worry, I don't bite anyone who doesn't bite me first." He was already unwinding the scarf from around his head.

  The imputation that this boy thought she was scared of him made her hand send the door sliding shut, jamming it into the wall with unnecessary force. She spun around and saw a young face with bright, laughing green eyes, and an angry red-dark scar set into his forehead that reminded her of something in the back of her mind but right now she had more important things to think about. "I didn't say I was Hermione Granger!"

  "I didn't say you said you were Hermione Granger, I just said
you were Hermione Granger. If you're asking how I know, it's because I know everything. Good evening ladies and gentlemen, my name is Harry James Potter-Evans-Verres or Harry Potter for short, I know that probably doesn't mean anything to you for a change -"

  Hermione's mind finally made the connection. The scar on his forehead, the shape of a lightning bolt. "Harry Potter! You're in Modern Magical History and The Rise and Fall of the Dark Arts and Great Wizarding Events of the Twentieth Century." It was actually the very first time in her whole life that she'd met someone from inside a book, and it was a rather odd feeling.

  The boy blinked three times. "I'm in books? Wait, of course I'm in books... what a strange thought."

  "Goodness, didn't you know?" said Hermione. "I'd have found out everything I could if it was me."

  The boy spoke rather dryly. "Miss Granger, it has been less than 72 hours since I went to Diagon Alley and discovered my claim to fame. I have spent the last two days buying science books. Believe me, I intend to find out everything I can." The boy hesitated. "What do the books say about me?"

  Hermione Granger's mind flashed back, she hadn't realised she would be tested on those books so she'd read them only once, but it was just a month ago so the material was still fresh in her mind. "You're the only one who's survived the Killing Curse so you're called the Boy-Who-Lived. You were born to James Potter and Lily Potter formerly Lily Evans on the 31st of July 1980. On the 31st of October 1981 the Dark Lord He-Who-Must-Not-Be-Named though I don't know why not attacked your home. You were found alive with the scar on your forehead in the ruins of your parents' house near the burnt remains of You-Know-Who's body. Chief Warlock Albus Percival Wulfric Brian Dumbledore sent you off somewhere, no one knows where. The Rise and Fall of the Dark Arts claims that you survived because of your mother's love and that your scar contains all of the Dark Lord's magical power and that the centaurs fear you, but Great Wizarding Events of the Twentieth Century doesn't mention anything like that and Modern Magical History warns that there are lots of crackpot theories about you."

  The boy's mouth was hanging open. "Were you told to wait for Harry Potter on the train to Hogwarts, or something like that?"

  "No," Hermione said. "Who told you about me?"

  "Professor McGonagall and I believe I see why. Do you have an eidetic memory, Hermione?"

  Hermione shook her head. "It's not photographic, I've always wished it was but I had to read my school books five times over to memorize them all."

  "Really," the boy said in a slightly strangled voice. "I hope you don't mind if I test that - it's not that I don't believe you, but as the saying goes, 'Trust, but verify'. No point in wondering when I can just do the experiment."

  Hermione smiled, rather smugly. She so loved tests. "Go ahead."

  The boy stuck a hand into a pouch at his side and said "Magical Drafts and Potions by Arsenius Jigger". When he withdrew his hand it was holding the book he'd named.

  Instantly Hermione wanted one of those pouches more than she'd ever wanted anything.

  The boy opened the book to somewhere in the middle and looked down. "If you were making oil of sharpness -"

  "I can see that page from here, you know!"

  The boy tilted the book so that she couldn't see it any more, and flipped the pages again. "If you were brewing a potion of spider climbing, what would be the next ingredient you added after the Acromantula silk?"

  "After dropping in the silk, wait until the potion has turned exactly the shade of the cloudless dawn sky, 8 degrees from the horizon and 8 minutes before the tip of the sun first becomes visible. Stir eight times widdershins and once deasil, and then add eight drams of unicorn bogies."

  The boy shut the book with a sharp snap and put the book back into his pouch, which swallowed it with a small burping noise. "Well well well well well well. I should like to make you a proposition, Miss Granger."

  "A proposition?" Hermione said suspiciously. Girls weren't supposed to listen to those.

  It was also at this point that Hermione realised the other thing - well, one of the things - which was odd about the boy. Apparently people who were in books actually sounded like a book when they talked. This was quite the surprising discovery.

  The boy reached into his pouch and said, "can of pop", retrieving a bright green cylinder. He held it out to her and said, "Can I offer you something to drink?"

  Hermione politely accepted the fizzy drink. In fact she was feeling sort of thirsty by now. "Thank you very much," Hermione said as she popped the top. "Was that your proposition?"

  The boy coughed. "No," he said. Just as Hermione started to drink, he said, "I'd like you to help me take over the universe."

  Hermione finished her drink and lowered the can. "No thank you, I'm not evil."

  The boy looked at her in surprise, as though he'd been expecting some other answer. "Well, I was speaking a bit rhetorically," he said. "In the sense of the Baconian project, you know, not political power. 'The effecting of all things possible' and so on. I want to conduct experimental studies of spells, figure out the underlying laws, bring magic into the domain of science, merge the wizarding and Muggle worlds, raise the entire planet's standard of living, move humanity centuries ahead, discover the secret of immortality, colonize the Solar System, explore the galaxy, and most importantly, figure out what the heck is really going on here because all of this is blatantly impossible."

  That sounded a bit more interesting. "And?"

  The boy stared at her incredulously. "And? That's not enough?"

  "And what do you want from me?" said Hermione.

  "I want you to help me do the research, of course. With your encyclopedic memory added to my intelligence and rationality, we'll have the Baconian project finished in no time, where by 'no time' I mean probably at least thirty-five years."

  Hermione was beginning to find this boy annoying. "I haven't seen you do anything intelligent. Maybe I'll let you help me with my research."

  There was a certain silence in the compartment.

  "So you're asking me to demonstrate my intelligence, then," said the boy after a long pause.

  Hermione nodded.

  "I warn you that challenging my ingenuity is a dangerous project, and tends to make your life a lot more surreal."

  "I'm not impressed yet," Hermione said. Unnoticed, the green drink once again rose to her lips.

  "Well, maybe this will impress you," the boy said. He leaned forward and looked at her intensely. "I've already done a bit of experimenting and I found out that I don't need the wand, I can make anything I want happen just by snapping my fingers."

  It came just as Hermione was in the middle of swallowing, and she choked and coughed and expelled the bright green fluid.

  Onto her brand new, never-worn witch's robes, on the very first day of school.

  Hermione actually screamed. It was a high-pitched sound that sounded like an air raid siren in the closed compartment. "Eek! My clothes!"

  "Don't panic!" said the boy. "I can fix it for you. Just watch!" He raised a hand and snapped his fingers.

  "You'll -" Then she looked down at herself.

  The green fluid was still there, but even as she watched, it started to vanish and fade and within just a few moments, it was like she'd never spilled anything at herself.

  Hermione stared at the boy, who was wearing a rather smug sort of smile.

  Wordless wandless magic! At his age? When he'd only gotten the schoolbooks three days ago?

  Then she remembered what she'd read, and she gasped and flinched back from him. All the Dark Lord's magical power! In his scar!

  She rose hastily to her feet. "I, I, I need to go the toilet, wait here all right -" she had to find a grownup she had to tell them -

  The boy's smile faded. "It was just a trick, Hermione. I'm sorry, I didn't mean to scare you."

  Her hand halted on the door handle. "A trick?"

  "Yes," said the boy. "You asked me to demonstrate my intelligence. So I did some
thing apparently impossible, which is always a good way to show off. I can't really do anything just by snapping my fingers." The boy paused. "At least I don't think I can, I've never actually tested it experimentally." The boy raised his hand and snapped his fingers again. "Nope, no banana."

  Hermione was as confused as she'd ever been in her life.

  The boy was now smiling again at the look on her face. "I did warn you that challenging my ingenuity tends to make your life surreal. Do remember this the next time I warn you about something."

  "But, but," Hermione stammered. "What did you do, then?"

  The boy's gaze took on a measuring, weighing quality that she'd never seen before from someone her own age. "You think you have what it takes to be a scientist in your own right, with or without my help? Then let's see how you investigate a confusing phenomenon."

  "I..." Hermione's mind went blank for a moment. She loved tests but she'd never had a test like this before. Frantically, she tried to cast back for anything she'd read about what scientists were supposed to do. Her mind skipped gears, ground against itself, and spat back the instructions for doing a science investigation project:

  Step 1: Form a hypothesis.

  Step 2: Do an experiment to test your hypothesis.

  Step 3: Measure the results.

  Step 4: Make a cardboard poster.

  Step 1 was to form a hypothesis. That meant, try to think of something that could have happened just now. "All right. My hypothesis is that you cast a Charm on my robes to make anything spilled on it vanish."

  "All right," said the boy, "is that your answer?"

  The shock was wearing off, and Hermione's mind was starting to work properly. "Wait, that can't be right. I didn't see you touch your wand or say any spells so how could you have cast a Charm?"