Harry Potter and the Methods of Rationality

by Eliezer Yudkowsky

  Hermione, having finished hand-crafting her Chocolate Cake Sauce, began to dip her carrots in it and eat them.

  "Why do you ask?" said Harry. "Do you wish you were back in the Muggle world?"

  "Not exactly," Hermione said, as she crunched into both the carrot and the chocolate. "I was just, well, feeling strange about having wanted to be a witch... Did you want to be a wizard when you were little?"

  "Of course," Harry said promptly. "I also wanted psychic powers and super-strength and adamantium-reinforced bones and my own flying castle and sometimes I felt sad that I might have to settle for just being a famous scientist and an astronaut."

  Hermione nodded. "You know," she said softly, "I think the witches and wizards who grow up here don't really appreciate magic properly..."

  "Well, of course they don't," Harry said, "that's what gives us our advantage. Isn't that obvious? I mean seriously, that was bloody obvious to me within five minutes of walking into Diagon Alley." There was a puzzled look on the boy's face, like he couldn't understand why she was paying attention to something so ordinary.

  Chapter 74: SA, Escalation of Conflicts, Pt 9

  Harry walked forward a step, then another step, until a sense of unease began to pervade him, a disquiet in his nerves.

  He said nothing, lifted no hand; the pervading sense of unease would say it for him.

  From behind the closed door of the office came a whisper, carrying through the door as though no door were present.

  "It is not my office hours," said that cold whisper, "nor yet the time of our meeting. I take ten Quirrell points from you, and be glad it is not more."

  Harry stayed calm. Going through Azkaban had recalibrated his scale of emotional disturbances; and losing a House point, which had formerly rated five out of ten, now lay somewhere around zero point three. Harry's voice was likewise level, as he said, "You made a testable prediction and it was falsified, Professor. I only wished to note that."

  As Harry turned to go, he heard the door opening behind him, and he swung back around in some surprise.

  Professor Quirrell was leaning back in his chair, his head lolling back against its rest, as a parchment floated before him. Both the Defense Professor's hands rested limply on the desk, as though nerveless. He might have been a corpse, excepting that the ice-blue eyes still moved, back and forth, back and forth.

  The parchment vanished, and was replaced by another so quickly it was like the material had only flickered.

  Then the lips moved as well. "And from this," whispered the lips, "you infer what, Mr. Potter?"

  Harry was shaken by the sight, but his voice stayed even as he said, "That ordinary people do not always do nothing, and that Hermione Granger is in more danger from Slytherin House than you thought."

  The lips curved, ever so barely. "So you think I have failed in my grasp of human nature. But that is hardly the only possibility, boy. Do you see the other?"

  Harry furrowed his brows as he stared at the Defense Professor.

  "I tire of this," the Defense Professor whispered. "You will stand there until you see it for yourself, or else leave." As though Harry had stopped existing, the Defense Professor's eyes looked back to the parchment, once more scanning back and forth.

  It was six parchments later that Harry saw it, and said out loud, "You think your prediction failed because there was some other factor at work which was not in your model. Some reason why Slytherin House hates Hermione more than you realized. Like when the orbital calculations for Uranus were wrong, and the problem wasn't in Newton's Laws, it was that they didn't know about Neptune -"

  The parchment vanished, and was not replaced. The head rose from its lolling position then, facing Harry more directly, and the voice which issued forth was quiet, but not toneless. "I think, boy," Professor Quirrell said softly, but in something approaching his normal voice, "that if all Slytherin House hated her so much, I would have seen it. And yet three formidable fighters of that House did something rather than nothing, at risk and at cost to themselves. What force could have moved them, or willed their motion?" The icy blue glitter of the Defense Professor's eyes met Harry's own gaze. "Some hand possessed of influence within Slytherin, perhaps. Then how would that hand have benefited itself by harm done to the girl and her followers?"

  "Um..." said Harry. "It would have to be someone threatened by Hermione somehow, or someone who would get the credit if she was hurt? I don't know anyone who fits that profile, but then I don't know much about anyone in Slytherin outside first-year." The thought was also coming to Harry that deducing a hidden mastermind from a single mildly-unexpected attack seemed like insufficient evidence to support the prior improbability of the theory; but then it was Professor Quirrell who was doing the deducing...

  The Defense Professor was just looking at Harry, eyelids slightly lowered as though in impatience.

  "And yes," said Harry, "I am sure that Draco Malfoy isn't behind it."

  A hiss of outward air like a sigh. "He is the son of Lucius Malfoy, trained to the most exacting standards. Whatever you have seen of him, even in what seem to be unguarded moments when his mask slips and you trust that you have seen the truth beneath, even that may all be part of the face he chooses to show you."

  Only if Draco successfully cast the Patronus Charm as part of keeping up the act. But Harry didn't say that, of course; instead he just grinned slightly, and said, "So either you've really never read Draco's mind, or that's just what you want me to think."

  There was a pause. One of the hands turned over, beckoned a finger.

  Harry stepped into the room. The door closed behind him.

  "That was not something you should have said aloud in human speech," said Professor Quirrell's soft voice. "Legilimency, on Malfoy's heir? Did Lucius Malfoy learn of it, he would have me assassinated outright."

  "He would try," Harry said. It should have won a crinkle of Professor Quirrell's eyes, but the Defense Professor's face was unmoving. "But sorry."

  When the Defense Professor spoke again, his voice had once more become a cold whisper. "I suppose I could, and pity the assassin." His head fell back against the chair, lolled to one side, the eyes no longer meeting Harry's. "But these small games hardly hold my interest as they stand. Add Legilimency, and it ceases to be a game at all."

  Harry hardly knew what to say. He'd seen Professor Quirrell in an angry mood once or twice before, but this seemed emptier, and Harry didn't know what to say to it. What's bothering you, Professor Quirrell? he could not ask.

  "What does hold your interest?" Harry said a few moments later, after he'd worked it out as a safer-seeming strategy for redirecting Professor Quirrell's attention to positive things. Citing experimental results about keeping a gratitude journal as a strategy for improving life happiness didn't seem like it would be taken well.

  "I will tell you what does not hold my interest," said that icy whisper. "Grading Ministry-mandated essays does not hold my interest, Mr. Potter. But I have undertaken the position of Defense Professor at Hogwarts, and I will see it through to its end." Another parchment appeared in front of Professor Quirrell's head, and his eyes began to scan it. "Reese Belka held a high position in my armies before her folly. I will offer her the chance to stay rather than being expelled, if she tells me exactly of the forces which moved her. And I shall make clear to her what will happen if she lies. I do permit myself to read faces."

  The Defense Professor's finger pointed past Harry, toward the door.

  "But whether you were wrong about human nature," Harry said, "or whether there's some extra force at work in Slytherin House - either way, Hermione Granger is in more danger than you predicted. Last time it was three strong fighters, so what happens after -"

  "She wishes not my help, nor yours," said a soft cold voice. "I no longer find your concerns so entertaining as I once did, Mr. Potter. Go."

  Somehow, even though they were all equals and she definitely wasn't in charge, it was always Hermione who ended up
speaking first in this sort of situation.

  The four tables of Hogwarts, the four Houses having breakfast, were glancing over at where they, the eight members of S.P.H.E.W., had gathered off to one side.

  Professor Flitwick was also staring sternly at all of them from the Head Table. Hermione wasn't looking there, but she could feel Professor Flitwick's gaze on the back of her neck. Literally feel it. It was really creepy.

  "Why'd you tell Tracey you wanted to talk to us, Mr. Potter?" said Hermione, her tone crisp.

  "Professor Quirrell expelled Reese Belka from her army last night," Harry Potter said. "And from all her other after-school Defense activities. Do any of you see the significance of that? Miss Greengrass? Padma?"

  Harry's eyes swept over them, as Hermione exchanged a puzzled glance with Padma, and Daphne shook her head.

  "Well," Harry said quietly, "I wouldn't actually expect you to. But what it means is that you're in danger, and I don't know how much danger." The boy squared his shoulders, looking straight into Hermione's eyes. "I wasn't going to say this, but... I just wanted to offer to put you under whatever protection I could give. Make it clear to everyone that anyone who messes with you, is messing with the Boy-Who-Lived."

  "Harry!" said Hermione sharply. "You know I don't want -"

  "Some of them are my friends too, Hermione." Harry didn't take his eyes from hers. "And it's their decision, not yours. Padma? You told me that I owed you no debt for what I did, and that's the sort of thing a friend would say."

  Hermione broke her gaze from Harry, to look at where Padma was shaking her head.

  "Lavender?" Harry said. "You fought well in my army, and I'll fight for you if you wish it."

  "Thank you, General!" Lavender said crisply. "I mean Mr. Potter. No, though. I'm a heroine and a Gryffindor, and I can fight for myself."

  There was a pause.

  "Parvati?" Harry said. "Susan? Hannah? Daphne? I don't know any of you so well, but it's something I would offer anyone who came to ask it of me, I think."

  One by one, the other four girls shook their heads.

  Hermione realized what was coming, then, but she didn't see a single thing she could do about it.

  "And my loyal soldier, Chaotic Tracey?" said Harry Potter.

  "Really?" gasped Tracey, oblivious to the stabbing glares that Hermione and every other girl were directing at her. Tracey's hands flew artfully to her cheeks, though she didn't actually manage to blush, not that Hermione could see; and her brown eyes were, if not shining, at least opened very wide. "You'd do that? For me? I mean - I mean, of course, absolutely, General Chaos -"

  And so it was on that very morning that Harry Potter went over to the Gryffindor table, and then the Slytherin table, and told both Houses that anyone who hurt Tracey Davis, regardless of what she was doing at the time, would, quote, learn the true meaning of Chaos, unquote.

  It was with considerable restraint that Draco Malfoy managed to prevent himself from slamming his head repeatedly into his plate of toast.

  They weren't exactly scientists, the bullies of Hogwarts.

  But even they, Draco knew, were going to want to test it.

  The Society for the Promotion of Heroic Equality for Witches hadn't announced it, it didn't seem like it would do any good to announce it. But they had all quietly decided (or, in the case of Lavender, been shouted into it by all seven other girls) to take a break from fighting bullies for a while, at least until their Heads of House weren't looking at them quite so sharply anymore, and older students had stopped bumping Hermione into walls.

  Daphne had told Millicent that they were taking a break.

  And so it was with some puzzlement, a few days later, that Daphne looked at the parchment delivered to her at lunch, drawn in a hand so shaky it was almost unreadable, saying:

  2 this afternoon at the top of the stairs going up from the library REALLY IMPORTANT everyone has to be there - Millicent

  Daphne looked around, but she couldn't see Millicent anywhere in the Great Hall.

  "A message from your informant?" said Hermione, when Daphne told her. "That's odd - I didn't -"

  "You didn't what?" said Daphne, after the Ravenclaw girl had stopped in mid-sentence.

  The Sunshine General shook her head and said, "Listen, Daphne, I think we need to know where these messages come from before we keep following them. Look at what happened last time, how could anyone have known where those three bullies would be, unless they were in on it?"

  "I can't say -" Daphne said. "I mean, I can't say anything, but I know where the messages come from, and I know how anyone can know."

  Hermione gave Daphne a look that, for a moment, made the Ravenclaw girl look scarily like Professor McGonagall.

  "Uh huh," said Hermione. "And do you know how Susan suddenly turned into Supergirl?"

  Daphne shook her head, and said, "No, but I think it might be really important that if we get a message saying we should be somewhere, everyone has to be there." Daphne hadn't seen what had happened with Susan, after Daphne had tried to avert the prophecy by keeping Susan away. But she'd been told about it afterward, and now Daphne was afraid that...

  She might have possibly...

  Might possibly have Broken Something...

  "Uh huh," said Hermione, who was doing the McGonagall Stare again.

  Nobody seemed to know where it had started, who had started it. If you'd tried tracing it afterward, tracked it back word by word and mutter by mutter, you probably would have found it all going in a huge circle.

  Peregrine Derrick was tapped on his shoulder as he left Potions that morning.

  Jaime Astorga heard a whisper in his ear at lunch.

  Robert Jugson III discovered a tiny folded note under his plate.

  Carl Sloper overheard two older Gryffindors whispering about it, and they gave him significant glances as they walked past.

  Nobody seemed to know where the word began, or who had first spoken it, but it named the place, and it named the time, and it said that the color would be white.

  "Every single one of you had better be absolutely clear on this," said Susan Bones. The Hufflepuff girl, or whatever strange power had possessed her, wasn't even pretending to act normal anymore. The round-faced girl was striding through the halls with a firm, confident gait. "If we get there and it's just one bully, that's fine, you can fight them the regular way. My mysterious superpowers won't activate if there are no innocents in danger. But if five seventh-year bullies jump out of a closet, you know what you do? That's right, you run away and let me fight them. Finding a teacher is optional, the important thing is that you run away as soon as I create an opening. In a fight like that you are liabilities. You are civilian targets I have to worry about protecting. So you will get away as fast as possible and you will not try to do anything heroic or so help me, the hour you get out of your healer's beds I will personally show up and kick your asses right back in. Are we all clear on that?"

  "Yes," squeaked most of the girls, though in Hannah's case it came out, "Yes, Lady Susan!"

  "Don't call me that," snapped Susan. "And I don't think I heard you, Miss Brown! I'm warning you, I have friends who write plays and if you do anything dumb, posterity will remember you as Lavender, the Amazing Stupid Hostage."

  (Hermione was beginning to worry about just how many other Hogwarts students besides Harry had mysterious dark sides, and whether she was likely to develop one if she kept hanging out with them.)

  "Alright, Captain Bones," said Lavender in an unusually respectful tone, as they turned another corner along the shortest way to the library, passing through a rather large corridor studded with six sets of double doors, three sets on either side. "Can I ask if there's any way for me to become a double witch?"

  "Sign up for the Auror preparation program in your sixth year," said Susan. "It's the next best thing. Oh, and if a famous Auror offers to oversee your summer internship, just ignore anyone who warns you that he's a terrible influence or that you're al
most certainly going to die."

  Lavender was nodding rapidly. "Got it, got it."

  (Padma, who hadn't actually been there last time, was giving Susan very skeptical looks.)

  Then Susan suddenly stopped in place and her wand snapped up and she said, "Protego Maximus!"

  A jolt of adrenaline went through Hermione, she was instantly drawing her wand and spinning around -

  But she couldn't see anything wrong, through the greater blue haze now surrounding them all.

  The other girls, who had likewise pulled into formation, were also looking puzzled.

  "Sorry!" said Susan. "Sorry, girls. Give me a moment to check this place out. Thinking of a certain person has just reminded me that this hall we're in right now, with all those doors, would be an excellent place for an ambush."

  There was a moment of silence.

  "Now," said a harsh male voice, blurred into unidentifiability by a buzzing undertone.

  All six sets of double doors slammed open.

  White robes filed silently forward, all-concealing white robes without marks of House affiliation and white cloth hiding the faces beneath the hoods. They marched out, and marched out, crowding the great corridor in numbers too high to count easily. Less than fifty robes, probably. Certainly more than thirty. All of them already surrounded by blue haze.

  Susan said some Extremely Bad Words, so awful that at almost any other time, Hermione would have noticed.

  "That message!" Daphne cried in sudden horror. "It wasn't from -"

  "Millicent Bulstrode?" said the voice and its buzzing undertone. "No, it wasn't. You see, Miss Greengrass, if the same girl sends off a Slytherin message every day you fight a bully, pretty soon someone else will notice. We'll have a talk with her after we're done with you."

  "Miss Susan," said Hannah in a voice just starting to quaver, "can you be super enough to -"