Harry Potter and the Methods of Rationality

by Eliezer Yudkowsky

  It was, for a start, the largest classroom he had yet seen at Hogwarts, akin to a major university classroom, with layered tiers of desks facing a gigantic flat stage of white marble. The classroom was high up in the castle - on the fifth floor - and Harry knew that was as much explanation as he'd get for where a room like this was supposed to fit. It was becoming clear that Hogwarts simply did not have a geometry, Euclidean or otherwise; it had connections, not directions.

  Unlike a university hall, there weren't rows of folding seats; instead there were quite ordinary Hogwarts wooden desks and wooden chairs, lined up in a curve across each level of the classroom. Except that each desk had a flat, white, rectangular, mysterious object propped up on it.

  In the center of the gigantic platform, on a small raised dais of darker marble, was a lone teacher's desk. At which Quirrell sat slumped over in his chair, head lolled back, drooling slightly over his robes.

  Now what does that remind me of...?

  Harry had arrived at the lesson so early that no other students were there yet. (The English language was defective when it came to describing time travel; in particular, English lacked any words capable of expressing how convenient it was.) Quirrell didn't seem to be... functional... at the moment, and Harry didn't particularly feel like approaching Quirrell anyway.

  Harry selected a desk, climbed up to it, sat down, and retrieved the Defence textbook. He was around seven-eighths of the way through - he'd planned on finishing the book before this lesson, actually, but he was running behind schedule and had already used the Time-Turner twice today.

  Soon there were sounds as the classroom began to fill up. Harry ignored them.

  "Potter? What are you doing here?"

  That voice didn't belong here. Harry looked up. "Draco? What are you doing in oh my god you have minions."

  One of the lads standing behind Draco seemed to have rather a lot of muscle for an eleven-year-old, and the other was poised in a suspiciously balanced-looking stance.

  The white-blonde-haired boy smiled rather smugly and gestured behind him. "Potter, I introduce to you Mr. Crabbe," his hand moved from Muscles to Balance, "Mr. Goyle. Vincent, Gregory, this is Harry Potter."

  Mr. Goyle tilted his head and gave Harry a look that was probably supposed to mean something but ended up just looking squinty. Mr. Crabbe said "Please to meetcha" in a tone that sounded like he was trying to lower his voice as far as it could go.

  A fleeting expression of consternation crossed Draco's face, but was quickly replaced by his superior grin.

  "You have minions!" Harry repeated. "Where do I get minions?"

  Draco's smirk grew wider. "I'm afraid, Potter, that the first step is to be Sorted into Slytherin -"

  "What? That's not fair!"

  "- and then for your families to have an arrangement from before you were born."

  Harry looked at Mr. Crabbe and Mr. Goyle. They both seemed to be trying very hard to loom. That is, they were leaning forwards, hunching over their shoulders, sticking their necks out and staring at him.

  "Um... hold on," said Harry. "This was arranged years ago?"

  "Exactly, Potter. I'm afraid you're out of luck."

  Mr. Goyle produced a toothpick and began cleaning his teeth, still looming.

  "And," said Harry, "Lucius insisted that you were not to grow up knowing your bodyguards, and that you were only to meet them on your first day of school."

  That wiped the grin from Draco's face. "Yes, Potter, we all know you're brilliant, the whole school knows by now, you can stop showing off -"

  "So they've been told their whole lives that they're going to be your minions and they've spent years imagining what minions are supposed to be like -"

  Draco winced.

  "- and what's worse, they do know each other and they've been practising -"

  "The boss told ya to shut it," rumbled Mr. Crabbe. Mr. Goyle bit down on his toothpick, holding it between his teeth, and used one hand to crack the knuckles on the other.

  "I told you not to do this in front of Harry Potter!"

  The two looked a bit sheepish and Mr. Goyle quickly put the toothpick back in a pocket of his robes.

  But the moment Draco turned away from them to face Harry again, they went back to looming.

  "I apologise," Draco said stiffly, "for the insult which these imbeciles have offered you."

  Harry gave a meaningful look to Mr. Crabbe and Mr. Goyle. "I'd say you're being a little harsh on them, Draco. I think they're acting exactly the way I'd want my minions to act. I mean, if I had any minions."

  Draco's jaw dropped.

  "Hey, Gregory, you don' think he's tryna lure us away from the boss, do ya?"

  "I'm sure Mr. Potter wouldn't be that foolish."

  "Oh, I wouldn't dream of it," Harry said smoothly. "It's just something to keep in mind if your current employer seems unappreciative. Besides, it never hurts to have other offers while you're negotiating your working conditions, right?"

  "What's he doin' in Ravenclaw?"

  "I can't imagine, Mr. Crabbe."

  "Both of you shut up," Draco said through gritted teeth. "That's an order." With a visible effort, he transferred his attention to Harry again. "Anyway, what're you doing in the Slytherin Defence class?"

  Harry frowned. "Hold on." His hand went into his pouch. "Timetable." He looked over the parchment. "Defence, 2:30pm, and right now it's..." Harry looked at his mechanical watch, which read 11:23. "2:23, unless I've lost track of time. Did I?" If he had, well, Harry knew how to get to whatever lesson he was supposed to be at. God he loved his Time-Turner and someday, when he was old enough, they would get married.

  "No, that sounds right," Draco said, looking puzzled. His gaze turned to look over the rest of the auditorium, which was filling with green-trimmed robes and...

  "Gryffindorks!" spat Draco. "What're they doing here?"

  "Hm," Harry said. "Professor Quirrell did say... I forget his exact words... that he would be ignoring some of the Hogwarts teaching conventions. Maybe he just combined all his classes."

  "Huh," said Draco. "You're the first Ravenclaw in here."

  "Yup. Got here early."

  "What're you doing all the way in the back row, then?"

  Harry blinked. "I dunno, seemed like a good place to sit?"

  Draco made a scoffing sound. "You couldn't get any further away from the teacher if you tried." The blonde-haired boy leaned slightly closer. "Anyway, is it true about what you said to Derrick and his crew?"

  "Who's Derrick?"

  "You hit him with a pie?"

  "Two pies, actually. What am I supposed to have said to him?"

  "That he wasn't doing anything cunning or ambitious and he was a disgrace to Salazar Slytherin." Draco was staring intently at Harry.

  "That... sounds about right," Harry said. "I think it was more like, 'is this some kind of incredibly clever plot that will gain you a future advantage or is it really as much of a disgrace to the memory of Salazar Slytherin as it looks like' or something like that. I don't remember the exact words."

  "You're confusing everyone, you know," said the blonde-haired boy.

  "Huh?" Harry said in honest confusion.

  "Warrington said that spending a long time under the Sorting Hat is one of the warning signs of a major Dark Wizard. Everyone was talking about it, wondering if they should start sucking up to you just in case. Then you went and protected a bunch of Hufflepuffs, for Merlin's sake. Then you told Derrick he's a disgrace to Salazar Slytherin's memory! What's anyone supposed to think?"

  "That the Sorting Hat decided to put me in the House of 'Slytherin! Just kidding! Ravenclaw!' and I've been acting accordingly."

  Mr. Crabbe and Mr. Goyle both giggled, causing Mr. Goyle to quickly clap a hand to his mouth.

  "We'd better go get our seats," Draco said. He hesitated, straightened a bit, spoke a bit more fomally. "But I do want to continue our last conversation and I accept your conditions."

  Harry nodded.
"Would you mind terribly if I waited until Saturday afternoon? I'm in a bit of a contest right now."

  "A contest?"

  "See if I can read all my textbooks as fast as Hermione Granger did."

  "Granger," Draco echoed. His eyes narrowed. "The mudblood who thinks she's Merlin? If you're trying to show her up then all Slytherin wishes you the very best luck, Potter, and I won't bother you 'til Saturday." Draco inclined his head respectfully, and wandered off, tailed by his minions.

  Oh, this is going to be so much fun to juggle, I can already tell.

  The classroom was filling up rapidly now with all four colors of trim: green, red, yellow, and blue. Draco and his two friends seemed to be in the midst of trying to acquire three contiguous front-row seats - already occupied, of course. Mr. Crabbe and Mr. Goyle were looming vigorously, but it didn't seem to be having much effect.

  Harry bent over his Defence textbook and continued reading.

  At 2:35PM, when most of the seats were taken and no one else seemed to be coming in, Professor Quirrell gave a sudden jerk in his chair and sat up straight, and his face appeared on all the flat, white rectangular objects that were propped up on the students' desks.

  Harry was taken by surprise, both by the sudden appearance of Professor Quirrell's face and by the resemblance to Muggle television. There was something both nostalgic and sad about that, it seemed so much like a piece of home and yet it wasn't really...

  "Good afternoon, my young apprentices," said Professor Quirrell. His voice seemed to come from the desk screen and to be speaking directly to Harry. "Welcome to your first lesson in Battle Magic, as the founders of Hogwarts would have put it; or, as it happens to be called in the late twentieth century, Defence Against the Dark Arts."

  There was a certain amount of frantic scrabbling as students, taken by surprise, reached for their parchment or notebooks.

  "No," Professor Quirrell said. "Don't bother writing down what this subject was once called. No such pointless question will count toward your marks in any of my lessons. That is a promise."

  Many students sat straight up at that, looking rather shocked.

  Professor Quirrell was smiling thinly. "Those of you who have wasted time by reading your useless first-year Defence textbooks -"

  Someone made a choking sound. Harry wondered if it was Hermione.

  "- may have gotten the impression that although this subject is called Defence Against the Dark Arts, it is actually about how to defend against Nightmare Butterflies, which cause mildly bad dreams, or Acid Slugs, which can dissolve all the way through a two-inch wooden beam given most of a day."

  Professor Quirrell stood up, shoving his chair back from the desk. The screen on Harry's desk followed his every move. Professor Quirrell strode towards the front of the classroom, and bellowed:

  "The Hungarian Horntail is taller than a dozen men! It breathes fire so quickly and so accurately that it can melt a Snitch in midflight! One Killing Curse will bring it down!"

  There were gasps from the students.

  "The Mountain Troll is more dangerous than the Hungarian Horntail! It is strong enough to bite through steel! Its hide is resistant enough to withstand Stunning Hexes and Cutting Charms! Its sense of smell is so acute that it can tell from afar whether its prey is part of a pack, or alone and vulnerable! Most fearsome of all, the troll is unique among magical creatures in continuously maintaining a form of Transfiguration on itself - it is always transforming into its own body. If you somehow succeed in ripping off its arm it will grow another within seconds! Fire and acid will produce scar tissue which can temporarily confuse a troll's regenerative powers - for an hour or two! They are smart enough to use clubs as tools! The mountain troll is the third most perfect killing machine in all Nature! One Killing Curse will bring it down."

  The students were looking rather shocked.

  Professor Quirrell was smiling rather grimly. "Your sad excuse for a third-year Defence textbook will suggest to you that you expose the mountain troll to sunlight, which will freeze it in place. This, my young apprentices, is the sort of useless knowledge you will never find in my lessons. You do not encounter mountain trolls in open daylight! The idea that you should use sunlight to stop them is the result of foolish textbook authors trying to show off their mastery of minutia at the expense of practicality. Just because there is a ridiculously obscure way of dealing with mountain trolls does not mean you should actually try to use it! The Killing Curse is unblockable, unstoppable, and works every single time on anything with a brain. If, as an adult wizard, you find yourself incapable of using the Killing Curse, then you can simply Apparate away! Likewise if you are facing the second most perfect killing machine, a Dementor. You just Apparate away!"

  "Unless, of course," Professor Quirrell said, his voice now lower and harder, "you are under the influence of an anti-Apparition jinx. No, there is exactly one monster which can threaten you once you are fully grown. The single most dangerous monster in all the world, so dangerous that nothing else comes close. The Dark Wizard. That is the only thing that will still be able to threaten you."

  Professor Quirrell's lips were set in a thin line. "I will reluctantly teach you enough trivia for a passing mark on the Ministry-mandated portions of your first-year finals. Since your exact mark on these sections will make no difference to your future life, anyone who wants more than a passing mark is welcome to waste their own time studying our pathetic excuse for a textbook. The title of this subject is not Defence Against Minor Pests. You are here to learn how to defend yourselves against the Dark Arts. Which means, let us be very clear on this, defending yourselves against Dark Wizards. People with wands who want to hurt you and who will likely succeed in doing so unless you hurt them first! There is no defence without offence! There is no defence without fighting! This reality is deemed too harsh for eleven-year-olds by the fat, overpaid, Auror-guarded politicians who mandated your curriculum. To the abyss with those fools! You are here for the subject that has been taught at Hogwarts for eight hundred years! Welcome to your first year of Battle Magic!"

  Harry started applauding. He couldn't help himself, it was too inspiring.

  Once Harry started clapping there was some scattered response from Gryffindor, and more from Slytherin, but most students simply seemed too stunned to react.

  Professor Quirrell made a cutting gesture, and the applause died instantly. "Thank you very much," said Professor Quirrell. "Now to practicalities. I have combined all my first-year Battle classes into one, which allows me to offer you twice as much classroom time as Doubles sessions -"

  There were gasps of horror.

  "- an increased load which I will make up to you by not assigning any homework."

  The gasps of horror cut off abruptly.

  "Yes, you heard me correctly. I will teach you to fight, not to write twelve inches on fighting due Monday."

  Harry desperately wished he'd sat next to Hermione so he could see the look on her face now, but on the other hand he was pretty sure he was imagining it accurately.

  Also Harry was in love. It would be a three-way wedding: him, the Time-Turner, and Professor Quirrell.

  "For those of you who so choose, I have arranged some after-school activities that I think you will find quite interesting as well as educational. Do you want to show the world your own abilities instead of watching fourteen other people play Quidditch? More than seven people can fight in an army."

  Hot damn.

  "These and other after-school activities will also earn you Quirrell points. What are Quirrell points, you ask? The House point system does not suit my needs, because it makes House points too rare. I prefer to let my students know how they are doing more frequently than that. And on the rare occasions I offer you a written test, it will mark itself as you go along, and if you get too many related questions wrong, your test will show the names of students who got those questions right, and those students will be able to earn Quirrell points by helping you."

&nb
sp; ...wow. Why didn't the other professors use a system like that?

  "What good are Quirrell points, you wonder? For a start, ten Quirrell points will be worth one House point. But they will earn you other favors as well. Would you like to take your exam at an unusual time? Is there a particular session you would very much prefer to skip? You will find that I can be very flexible on behalf of students who have accumulated enough Quirrell points. Quirrell points will control the generalship of the armies. And for Christmas - just before the Christmas break - I will grant someone a wish. Any school-related feat that lies within my power, my influence, or above all, my ingenuity. Yes, I was in Slytherin and I am offering to formulate a cunning plot on your behalf, if that is what it takes to accomplish your desire. This wish will go to whoever has earned the most Quirrell points within all seven years."

  That would be Harry.

  "Now leave your books and loose items at your desks - they will be safe, the screens will watch over them for you - and come down onto this platform. It's time to play a game called Who's the Most Dangerous Student in the Classroom."

  Harry twisted his wand in his right hand and said "Ma-ha-su!"

  There was another high-pitched "bing" from the floating blue sphere that Professor Quirrell had assigned to Harry as his target. That particular sound meant a perfect strike, which Harry had been gotten on nine out of his last ten attempts.

  Somewhere Professor Quirrell had dug up a spell that was incredibly easy to pronounce, and had a ridiculously simple wand motion, and had a tendency to hit wherever you were currently looking at. Professor Quirrell had disdainfully proclaimed that real battle magic was far more difficult than this. That the hex was entirely useless in actual combat. That it was a barely ordered burst of magic whose only real content was the aiming, and that it would produce, when it hit, a pain briefly equivalent to being punched hard in the nose. That the sole purpose of this test was to see who was a fast learner, since Professor Quirrell was certain no one would have previously encountered this hex or anything like it.