Harry Potter and the Methods of Rationality

by Eliezer Yudkowsky

  ...it wasn't like he'd been about to leave the Muggle world to start a new era of magical research, and not take along any way of generating electricity.

  Shortly after, the Chaos Legionnaires heard the sound of fingers snapping, followed by a crackling noise from beneath the blanket. The shield started glowing more brightly, and Harry's voice said, "Don't be distracted please, eyes on General Malfoy."

  The strain was showing on Draco's face, along with the fury and annoyance and frustration.

  Harry smiled up at him, and mouthed, Tell you later.

  And that was when a spiral of green energy shot out of the forest and smashed into Draco's shield, which shrieked like pieces of sharp glass being rubbed together, and Draco staggered.

  In sudden, frantic panic, Harry took the jumper cables off the battery and fed them into the pouch, then he fed the battery itself into the pouch, and then he tore off the blanket and grabbed his wand and stood up.

  All of his soldiers were still there and glancing around frantically.

  "Contego," Harry said, and his soldiers followed suit, but Harry didn't even know which direction the shield ought to be pointing in. "Did anyone see where that came from?" Shaken heads. "And General Malfoy, would you mind telling me if you got General Granger?"

  "Why yes," Draco said acidly, "I mind."

  Oh, hell.

  Harry's mind began calculating, Draco inside the shield, Draco worn out now to some degree, Harry worn out too, Hermione in the woods who-knew-where, Harry and four other Chaotics left...

  "You know, General Granger," Harry said out loud, "you really should've waited to attack until after I'd fought General Malfoy. You might've been able to get all the survivors."

  From somewhere came a girl's high-pitched laughter.

  Harry froze.

  That wasn't Hermione.

  And that was when the dreadful, eerie, cheerful chant began to rise, coming from all around them.

  "Don't be frightened, don't be sad,

  We'll only hurt you if you're bad..."

  "Granger cheated!" burst out Draco inside the shield. "She woke up her soldiers! Why doesn't Professor Quirrell -"

  "Let me guess," Harry said, the sickness already churning in his stomach. He really hated losing. "It was a very easy battle, right? They dropped like flies?"

  "Yes," Draco said. "We got them all on the first shot -"

  The look of horrified realization spread from Draco to the Chaos Legionnaires.

  "No," Harry said, "we didn't."

  Camouflaged forms were appearing from among the trees.

  "Allies?" Harry said.

  "Allies," Draco said.

  "Good," said General Granger's voice, and a spiral of green energy blazed out of the woods and shattered Draco's shield to splinters.

  General Granger surveyed the battlefield with a definite feeling of satisfaction. She was down to nine Sunshine Soldiers, but that was probably enough to handle the last survivor of the enemy forces, especially when Parvati and Anthony and Ernie were already holding their wands on General Potter, whom she'd ordered taken alive (well, conscious).

  It was Bad, she knew, but she'd really really really wanted to gloat.

  "There's a trick, isn't there?" said Harry, the strain showing in his voice. "There has to be some trick. You can't just turn into a perfect general. Not on top of everything else. You're not that Slytherin! You don't write creepy poetry! No one's that good at everything!"

  General Granger glanced around at her Sunshine Soldiers, and then looked back at Harry. Everyone was probably watching this on the screens outside.

  And General Granger said, "I can do anything if I study hard enough."

  "Oh now that's just bu-"

  "Somnium."

  Harry slumped to the ground in mid-sentence.

  "SUNSHINE WINS," intoned the huge voice of Professor Quirrell, seeming to come from everywhere and nowhere.

  "Niceness has triumphed!" cried General Granger.

  "Hooray!" shouted the Sunshine Soldiers. Even the Gryffindor boys said it, and they said it with pride.

  "And what's the moral of today's battle?" said General Granger.

  "We can do anything if we study hard enough!"

  And the survivors of the Sunshine Regiment marched off toward the victory field, singing their marching song as they went:

  Don't be frightened, don't be sad,

  We'll only hurt you if you're bad,

  And send you to a home that's true,

  With new friends to watch over you,

  Be sure to tell them you were sent

  By Granger's Sunshine Regiment!

  Chapter 31: Working in Groups, Pt 2

  Aftermaths:

  Harry paced backward and forward in his general's office, which made a wonderful room for pacing, it didn't have any other uses as far as he could tell.

  How?

  How?

  Hermione shouldn't have won that battle! Not on her first try, not when she wasn't at all violent by her nature, automatically being a great military commander on top of everything else was too much even for her.

  Had she read about the tactic in a military history book? But it hadn't been just that one tactic, she'd had her forces perfectly positioned to block any retreat, her troops had been better coordinated than his or Draco's...

  Had Professor Quirrell broken his promise not to help her? Had he given her the diary of General Tacticus or something?

  Harry was missing something here, something really important, and his mind went around and around in circles, and he still couldn't figure it out.

  Finally Harry sighed. He wasn't getting anywhere on this, and he had to go learn the Breaking Drill Hex from Hermione or someone before the next battle - Professor Quirrell had explained to Harry, his voice amused but with a sharp undertone of warning, that "no magical items except the ones I give you" included Muggle technology no matter how much that wasn't magic. Plus Harry also needed to figure out how to bring down Mr. Goyle next time...

  Battles counted for a lot of Quirrell points if you were a general, and Harry needed to get cracking if he wanted to win Professor Quirrell's Christmas wish.

  In his private room at Slytherin, Draco Malfoy stared off into space, as though the wall in front of his desk was the most fascinating surface in the world.

  How?

  How?

  In retrospect it had been an obvious sort of idea as cunning plots went, but Granger wasn't supposed to be cunning! She'd been too much of a Hufflepuff to use a Simple Strike Hex! Had Professor Quirrell been advising her despite his promise, or...

  And then Draco finally did what he should have done much earlier.

  What he should have done after the first time he met with Granger.

  What Harry Potter had told him to do, trained him to do, and yet Harry had also warned Draco that it would take time to make his brain realize that the methods applied to real life, and Draco hadn't understood that until today. He could have avoided every single one of his mistakes if he'd just applied the things Harry had already told him -

  Draco said out loud, "I notice that I am confused."

  Your strength as a rationalist is your ability to be more confused by fiction than by reality...

  Draco was confused.

  Therefore, something he believed was fiction.

  Granger should not have been able to do all that.

  Therefore, she probably hadn't.

  I promise not to help General Granger in any way that the two of you don't know about.

  With sudden horrified realization, Draco swept papers out of the way, hunting through the mess on his desk, until he found it.

  And there it was.

  Right in the list of people and equipment assigned to each of the three armies.

  Curse Professor Quirrell!

  Draco had read it and he still hadn't seen it -

  The afternoon sunlight poured down into the office of the Sunshine Regiment, illuminating Genera
l Granger in her chair as though she glowed with a golden aura.

  "How long do you think it will take Malfoy to figure it out?" said General Granger.

  "Not long," said Colonel Blaise Zabini. "He may have already. How long will it take Potter to figure it out?"

  "Forever," said General Granger, "unless Malfoy tells him, or one of his own soldiers realizes. Harry Potter just doesn't think like that."

  "Really?" said Captain Ernie Macmillan, looking up from one of the corner tables where he was being crushed at chess by Captain Ron Weasley. (They'd brought back all the other chairs after Malfoy had left, of course.) "I mean it seems kind of obvious to me. Who would try to come up with all the ideas just by themselves?"

  "Harry," said Hermione, at exactly the same time Zabini said, "Malfoy."

  "Malfoy thinks he's way better than everyone else," said Zabini.

  "And Harry... doesn't really see most other people like that," said Hermione.

  It was kind of sad, actually. Harry had grown up very, very alone. It wasn't that he went around thinking in words that only geniuses had a right to exist. It just wouldn't occur to him that anyone in Hermione's army besides Hermione could have any good ideas.

  "Anyhow," Hermione said. "Captains Goldstein and Weasley, you're on duty for thinking up strategic ideas for our next battle. Captains Macmillan and Susan - sorry, I mean Macmillan and Bones - try to come up with some tactics we can use, also any training you think we should try. Oh, and congratulations on your marching song, Captain Goldstein, I think it was a big plus for esprit de corps."

  "What're you doing?" said Susan. "And Colonel Zabini?"

  Hermione stood up out of her chair, stretching. "I'll try to figure out what Harry Potter is thinking and Colonel Zabini will try to figure out what Draco Malfoy might do, and both of us will join you again after we come up with something. I'm going to walk while I think. Zabini, you want to come along?"

  "Yes, General," said Zabini stiffly.

  It hadn't been meant as an order. Hermione sighed to herself a little. This was going to take some getting used to, and although Zabini's first idea had certainly worked, she wasn't quite sure that Professor Quirrell's quote mixture of positive and negative incentives unquote would be enough to keep the Slytherin fully on her side until December when traitors would be allowed for the first time...

  She still had no idea what she was going to do with Professor Quirrell's Christmas wish, either. Maybe she'd just ask Mandy if she wanted anything, when the time came around.

  Chapter 32: Interlude: Personal Financial Management

  "But Headmaster," Harry argued, some of his desperation leaking into his voice, "leaving all of my assets in one undiversified vault full of gold coins - it's crazy, Headmaster! It's like, I don't know, doing Transfiguration experiments without consulting a recognized authority! You just don't do that with money!"

  From the lined face of the old wizard - underneath a festive holiday hat like a catastrophic automobile collision between cars of green and red cloth - a grave, sad look peered out at Harry.

  "I'm sorry, Harry," said Dumbledore, "and I do apologize, but allowing you control over your own finances would give you far too much independence of action."

  Harry's mouth opened and no sound came out. He was, literally, speechless.

  "I will permit you to withdraw five Galleons for Christmas presents," said Dumbledore, "which is more than any boy your age should spend, but poses no threat, I think -"

  "I can't believe you just said that!" the words burst out of Harry's mouth. "You admit to being that manipulative?"

  "Manipulative?" said the old wizard, smiling slightly. "No, manipulative would be if I did not admit it, or if I had some deeper motive behind the obvious. This is quite straightforward, Harry. You are not yet ready to play the game, and it would be foolish to allow you thousands of Galleons with which to upset the gameboard."

  The bright hustle and bustle of Diagon Alley had increased by a hundredfold and redoubled as Christmas approached, with all the shops enshrouded in brilliant sorceries that flashed and sparkled as though the season's spirit was about to blaze out of control and turn the whole area into a cheerful holiday crater. The streets were so crowded with witches and wizards in festive and loud clothing that your eyes were assaulted almost as severely as your ears; and it was clear, from the bewildering variety of the shoppers, that Diagon Alley was considered an international attraction. There were witches wrapped in giant swathes of cloth like toweled mummies, and wizards in formal top hats and bath-robes, and young children barely past toddling age who were decorated with lights that blazed almost as bright as the shops themselves, as their parents took them hand in hand through that magic wonderland and let them shriek to their heart's content. It was the season to be merry.

  And in the midst of all that light and cheer, a note of blackest night; a cold, dark atmosphere that cleared a few precious paces of distance even in the midst of all that crush.

  "No," said Professor Quirrell, with a look of grim revulsion, like he'd just bitten into food that not only tasted horrible but was morally repugnant to boot. It was the sort of grim face an ordinary person might make after biting into a meat pie, and discovering that it was rotten and had been made from kittens.

  "Oh, come on," Harry said. "You must have some ideas."

  "Mr. Potter," Professor Quirrell said, his lips set in a thin line, "I agreed to act as your adult guardian on this expedition. I did not agree to advise you on your choice of presents. I don't do Christmas, Mr. Potter."

  "How about Newtonmas?" Harry said brightly. "Isaac Newton actually was born on December 25th, unlike some other historical figures I could name."

  This failed to impress Professor Quirrell.

  "Look," said Harry, "I'm sorry, but I've got to do something special for Fred and George and I've got no idea of my options."

  Professor Quirrell made a thoughtful humming sound. "You could ask which family members they most dislike, and then hire an assassin. I know someone from a certain government-in-exile who is quite competent, and he would give you a discount on multiple Weasleys."

  "This Christmas," Harry said, dropping his voice into a lower register, "give your friends the gift... of death."

  That made Professor Quirrell smile. It went all the way to his eyes.

  "Well," said Harry, "at least you didn't suggest getting them a pet rat -" Harry's mouth snapped shut, and he was regretting the words almost as soon as they were out of his mouth.

  "Pardon me?" said Professor Quirrell.

  "Nothing," Harry said at once, "long dumb story." And telling it seemed wrong somehow, maybe because Harry was afraid Professor Quirrell would have laughed even if Bill Weasley hadn't been cured and everything put back to right...

  And where had Professor Quirrell been that he'd never heard the story? Harry had gotten the impression that everyone in magical Britain knew.

  "Look," said Harry, "I'm trying to solidify their loyalty to me, you know? Make the Weasley twins my minions? Like the old saying goes: A friend isn't someone you use once and then throw away, a friend is someone you use over and over again. Fred and George are two of the most useful friends I have in Hogwarts, Professor Quirrell, and I plan to use them over and over again. So if you'd help me be Slytherin here, and suggest something they might be very grateful for..." Harry's voice trailed off invitingly.

  You just had to pitch these things the right way.

  They walked on for a good way before Professor Quirrell spoke again, his voice practically dripping with distaste. "The Weasley twins are using secondhand wands, Mr. Potter. They would be reminded of your generosity with every Charm they cast."

  Harry clapped his hands together in involuntary excitement. Just put the money on account at Ollivander's, and tell Mr. Ollivander to never refund it - no, better yet, to send it to Lucius Malfoy if the Weasley twins didn't show up before the start of their next school year. "That's brilliant, Professor!"

  Profes
sor Quirrell did not look like he appreciated the compliment. "I suppose I can tolerate Christmas in that spirit, Mr. Potter, though only barely." Then he smiled slightly. "Of course that will cost you fourteen Galleons, and you only have five."

  "Five Galleons," Harry said, with a sniff of outrage. "Just who does the Headmaster think he's dealing with, anyway?"

  "I think," said Professor Quirrell, "that it simply did not occur to him to fear the consequences if you turned your ingenuity to the task of obtaining funds. Though you were wise to lose, rather than making it an explicit threat. Out of curiosity, Mr. Potter, what would you have done if I hadn't turned away in boredom while you, in a fit of childish pique, counted out five Galleons worth of Knuts?"

  "Well, the easiest way would've been to borrow money from Draco Malfoy," said Harry.

  Professor Quirrell chuckled briefly. "Seriously, Mr. Potter."

  Duly noted. "Probably I'd have done a few celebrity appearances. I wouldn't resort to anything economically disruptive just for spending money." Harry had checked, and he would be allowed to keep the Time-Turner while he went home for the holidays, so that his sleep cycle didn't start to rotate. But then it was also possible that someone kept an eye out for magical day traders. The gold and silver trick would've taken work on the Muggle end, and seed funding, and the goblins might've gotten suspicious after the first cycle. And starting a real bank would be a lot of work... Harry hadn't quite worked out any money-making methods that were fast and certain and safe, so he'd been very glad when Professor Quirrell had turned out to be so easily fooled.

  "I do hope those five Galleons will be enough to last, since you counted them so carefully," said Professor Quirrell. "I doubt the Headmaster shall be so eager to entrust me with your vault key a second time, once he discovers I've been tricked."

  "I'm sure you did your best," Harry said with deep gratitude.

  "Do you need any assistance finding a safe place to store all those Knuts, Mr. Potter?"

  "Well, sort of," said Harry. "Do you know of any good investment opportunities, Professor Quirrell?"