This is a fanfic of LessWrong's famous Harry Potter and the Methods of Rationality. In this alternate world, Petunia married an Oxford Professor named Michael Verres instead of Vernon Dursley, and Harry is raised with an understanding of science and rationality by the time the letters from Hogwarts arrive.
I'm merely experimenting with a rewrite of the first few chapters to examine how they might be "smoothed out" to better match the rest of the story in tone and characterization, and adding more context so as not to assume the readers are familiar with the canon series. Harry Potter is owned by J.K. Rowling.
Chapter 1: A Day of Very Low Probability
Beneath the moonlight glints a tiny fragment of silver, a fraction of a line...
(black robes, falling)
...blood spills out in litres, and someone screams a word.
Harry James Potter-Evans-Verres was doing his best to ignore the yelling outside his cupboard.
It was an hour before supper, and he was lying in the cupboard under the stairs and reading a fantasy novel. Normally he enjoyed reading in companionable silence with his father in his study, or tuning out the sound of his mother's soap operas in the living room, but when he wanted quiet that even his room couldn't provide, he would go under the stairs. It was a private, cozy place, mostly insulated from the sounds of phone conversations, television, or outside traffic.
This particular night, however, the walls were no match for the steadily rising voices of Michael and Petunia Evans-Verres, and soon Harry began to catch bits and pieces of the conversation.
"...just rubbish... fourth time this week... a silly prank, Petunia-"
Harry adjusted his glasses and tried to concentrate on the book. The author was attempting to explain, through an old wizard's limited grasp of biology and chemistry, how the dragons in his world breathed fire. Though Harry generally preferred science-fiction, he always enjoyed fantasy best when the writers at least tried to put some of the magic in rational, understandable terms: it fired up his imagination to think outside the box for what was possible, if not terribly probable.
"-not a prank, I told you... have to show him, or they'll keep... more and more of them..."
"...nonsense, there's no need... about crackpots sending him letters!"
Unfortunately, now his imagination was preoccupied with what kinds of letters his dad was keeping from him. Harry closed his book, no longer able to concentrate as a familiar bitterness flared up in him.
It wasn't that his parents mistreated him. Far from it: he'd been sent to the best primary schools, and when that proved insufficient was given the best tutors an endless pool of starving university students could provide. He'd always been encouraged to study whatever caught his attention, was bought all the books he wanted, was sponsored in whatever maths or science competitions he entered. He knew he was exceedingly lucky, and was always grateful for what his parents gave him... but he would have been satisfied with half as much if it meant he had their respect.
Of course if asked, his parents would say they respected him. An Oxford Professor of Biochemistry and his liberal wife were expected to show an enlightened view of child-rearing that included respect... but that respect meant something different than it would for a fellow adult, who they would never have dreamed of talking about as if he weren't in the house, let alone making decisions for him.
It wasn't their fault; society as a whole had such low expectations of children. And if it was ever going to change, it would be up to those like him to change it.
So Harry swung his legs out of the small hammock he'd strung to the walls, turned off the lantern his father had hung up for him, and opened the door into the hallway.
The voices immediately quieted. By the time he stepped into the living room his parents were sitting calmly on the couch, watching the news on a television that stuck out from its surroundings. The Evans-Verres living room was dominated by books. Every inch of wall space was covered by a bookcase going almost to the ceiling. Some bookshelves were stacked to the brim with hardback books: science, maths, history, and everything else. Other shelves had two layers of paperback science fiction, one set right side up, the other stacked sideways in what's left of the space above. And it still wasn't enough. Books were overflowing onto the tables and the sofas, covered the top of the television, and made little stacks under the windows.
"Hi Mum, Dad. Is everything alright?"
"Hello, Harry." His mother turned to him with a warm smile, face still young and pretty despite her age. "Yes, everything's fine."
"Did we disturb your reading, Son?" his father asked, looking contrite. "Our debate got a bit passionate at the end there."
Harry and his mother exchanged knowing smiles. Professor Evans-Verres viewed arguments as uncivilized, and so any he participated in were automatically elevated in status to "debate." "It's alright. I just couldn't help but overhear," Harry said with mild emphasis, "and it sounded like a letter arrived for me?"
He saw it in the quick glance they gave each other, his mother's expectant, his father's calculating. Harry knew his father was struggling with some mighty cognitive dissonance. One part of him felt guilt from withholding someone's mail from them, a grievous breach of privacy. The other part felt entitled by societal norms that parents were allowed to decide for their children what information they should or shouldn't have, no matter how bright and precocious those children might be.
"Yes," Petunia said after the silence stretched on a few seconds. "It's the first time I've seen it, or I would have told you sooner. Your father thinks it's just prank mail, but he doesn't understand-"
"Well no harm in having a look then, right?" Harry said, and held his hand out expectantly, brow raised in an expression of innocent patience. He wasn't quite sure what he'd do if his father refused, trying to reason with him rarely worked on any topic that concerned Harry's subordinate status...
After a moment though his father nodded and stood up, walking toward the trash and fishing an envelope and a couple sheets of paper from it. "Quite right Harry, no harm in looking. You're a bright boy, and I know you won't get suckered in by whatever crock they're selling."
Michael handed the letters and envelope to Harry, who had to choke back a retort to the patronizing tone his father had adopted now that he was giving in. Admitting one's mistakes was for scientific journals, apparently, and not for adults to do to children...
Harry chided himself on the bitter thoughts as he went to the table. He knew this was a sore spot for him, and it occasionally took a while for his temper to calm down. So he forced himself to smile back at his dad, then straightened the first thick, rich sheet of paper out and began to read, acutely aware of his parents' stares.
Harry's eyes scanned the letter in a few seconds, blinked, then looked up to meet theirs.
Michael Evans-Verres smiled. "Yes, rather silly I th-"
Harry held his hand up, then looked back down at the parchment (that's what you'd call material like this, Harry knew, simple "paper" didn't suffice) and slowly reread the message.
Dear Mr. Potter,
We are pleased to inform you that you have been accepted at Hogwarts School of Witchcraft and Wizardry. Please find enclosed a list of all necessary books and equipment.
Term begins on 1 September. We await your owl by no later than 31 July.
On the second sheet he found a list that wouldn't be out of place in a fantasy role-playing game rulebook.
"What is it, some kind of late summer camp?" Harry asked as he eyed the impressive seal heading the parchment: a lion, snake, raven and badger surrounding an ornate H. He smiled as he looked back at the name of the school. What, was "Newteyes" taken?
"No, Harry," his mother said. "It's not a summer camp. As I was telling your father..." She took a deep breath, straightened in her seat, and avoided looking at her husband, gaze steady on Harry. "My sister... your mother, Lily... was a witch. She got that same letter. I'd promised to keep it secret, my whole family did, but now it's clear you're meant to know, if they've come for you like they did her."
Harry exchanged a glance with his father this time, feeling a mix of exasperation and confusion. Mum rarely spoke of his biological parents. It wasn't taboo or anything, it just never really came up. They'd died in a car crash when he was one year old, the same crash which had given him the lightning shaped scar on his forehead. To hear that they were Wiccan wasn't terribly surprising considering some of Petunia's beliefs, but the gravity of her tone didn't match the subject matter.
"Well that's, er, very interesting, I guess. But what does her religion have to do with me? Who's 'they?'" He didn't particularly like the ominous sound of them "coming for him," whoever they were. He imagined a shadowy coven meeting in a forest and pronouncing it time to bring the young Potter into the fold.
"It wasn't a religion. I'm saying she was an actual witch. She could do magic. Her husband, your father, was a wizard. They both went to this magic school, Hogwarts, when they were eleven. And that you got that letter, it means you're a wizard too, Harry."
Michael Evans-Verres laughed, and Harry almost joined him. Petunia Evans-Verres had always been something of the odd-woman-out in their family. Some of the most "spirited debates" he could remember between his parents involved her superstitions, and he had a clear memory as a child of her waving a crystal of some kind in careful patterns over him when he was sick.
When he was younger he used to enjoy going with her to the smoky, mysterious shops she would occasionally frequent, with their pungent odors and exotic wares. Thankfully his father's books had taught him how to critically examine the beliefs sold in such places, and a few years ago he had begun to find their air of obscure mysticism groundless and mildly irritating.
Harry smiled down at the parchment listing the "school supplies." Wand, spell books, potion ingredients... he quickly scanned the latter. Nope, no "hog warts" listed, though newt eyes did indeed show up, as well as powdered hens' teeth. He wondered how expensive that would be; he knew there was some research being done on atavism in chickens that resulted in them growing vestigial teeth, and that the mutation was rather rare. Aboriginal medicine men must have found plenty of uses for it, or imagined them at any rate. He wondered what Hogwarts pretended to use them for. Good dental hygiene?
And yet he didn't laugh with his father. Because...
Because somewhere in him was a strange certainty that she was right, in this, the most unlikely of cases. You're a wizard too, Harry.
"Well, maybe someday he'll be a wizard at chess," his father said, still smiling as he turned back to the news. "But if whoever keeps sending those letters shows up at the door in a robe and pointy hat, I'm calling the men in the white coats."
Petunia continued to look only at Harry, her gaze intent, waiting.
"Mum," he said. "What do you mean by 'wizard?'"
Petunia bit her lip. "I can't just tell you. You'll think I'm-" She swallowed, and Harry felt confused again. His mother had always defended her less rational beliefs with an exasperating calm, merely shrugging off logical arguments and relying on some inner conviction. This sudden nervousness, and the confusion he felt from it, made him pay attention. "Listen. I wasn't—always like this—" She gestured at herself, as though to indicate her lithe form. "Lily did this. Because I... I begged her. For years, I begged her. Lily had always been prettier than me, and I'd... been mean to her, because of that, and then she got magic, can you imagine how I felt? And I begged her to use some of that magic on me so that I could be pretty too, even if I couldn't have her magic, at least I could be pretty."
Harry watched in alarm as tears gathered in Petunia's eyes.
"And Lily would tell me no, and make up the most ridiculous excuses, like the world would end if she were nice to her sister, or a centaur told her not to—the most ridiculous things, and I hated her for it. And when I had just graduated from university, I was going out with this boy, Vernon Dursley, he was fat and he was the only boy who would talk to me. And he said he wanted children, and that his first son would be named Dudley. And I thought to myself, what kind of parent names their child Dudley Dursley? It was like I saw my whole future life stretching out in front of me, and I couldn't stand it. And I wrote to my sister and told her that if she didn't help me I'd rather just—"
Petunia stopped. Harry felt somewhat wretched for being responsible for her having to relate such an obviously painful memory. A glance at his father showed his dad similarly stricken. He'd never known that Mum had been through such a dark period, had been so envious of her sister... he wondered how much guilt she must have felt after his biological parents had died.
"Anyway," Petunia said, voice small. "She gave in. She warned me it was dangerous, and I said I didn't care. I drank this potion and I was sick for weeks, but when I got better my skin cleared up and I finally filled out and... I was beautiful. People were nice to me," her voice broke, "and after that I couldn't hate my sister any more, especially when I learned what her magic brought her in the end—"
"Darling," Michael said gently, "you got sick, you gained some weight while resting in bed, and your skin cleared up on its own. Or being sick made you change your diet—"
"No, it was nothing like that. It was magic, real magic. I saw it, other things, like people disappearing—"
"Petunia," Michael said. The annoyance was creeping back into his voice. "You know that can't be true. Do I really have to explain why?"
Petunia wrung her hands. She seemed to be on the verge of tears. "My love, I know I can't win arguments with you, but please, I wish you'd just trust me on this—"
The two of them stopped and looked at Harry. He took a deep breath and thought about the problem. "Mum, your parents didn't have magic, did they?"
"No," Petunia said. "Just Lily."
"Then your family also must not have believed her letter. How did they get convinced?"
"Ah... They didn't just send a letter. They sent a professor from Hogwarts. He..." Petunia's eyes flicked to Michael. "He showed us some magic."
"Well there we are then. You don't have to fight over this," Harry said firmly as the obvious solution came to mind, hoping against hope that he could convince them, keep them from arguing further... "If it's true, we can just get a Hogwarts professor here and see the magic for ourselves, and Dad will admit that it's true. And if not, then Mum will admit that it's false. That's what the experimental method is for, right?"
"Oh, come now, Harry," Professor Evans-Verres said. "Really, magic? I thought you'd know better than to take this seriously, even if you're only ten."
I. Shall. SCREAM.
"Mum," Harry said instead, doing his best to keep his voice calm. "If you want to win this argument with Dad, look in chapter two of the first book of the Feynman Lectures on Physics. There's a quote there about how philosophers say a great deal about what science absolutely requires, and it's all wrong, because the only rule in science is that the final arbiter is observation—that you just have to look at the world and report what you see. Um... off the top of my head I can't think of where to find something about how it's an ideal of science to settle things by experiment instead of arguments, but..."
His mother just smiled. "Thank you, Harry. But," she looked back at her husband. "I don't want to win an argument with your father. I want my husband to just... listen to his wife who loves him, and trust her just this once..."
Harry closed his eyes briefly. Hopeless. Both of his parents were hopeless.
Now they were getting into one of those arguments again, one where his mother tried to make her husband feel guilty, and his father tried to make his wife feel stupid.
"I'm going to go to my room," Harry announced. His voice trembled a little. "Please try not to fight too much about this, Mum, Dad, we'll know soon enough how it comes out, right?"
"Of course, Harry," said his father, and his mother gave him a reassuring kiss, and then they went on "debating" while Harry climbed the stairs to his bedroom.
He shut the door behind him and tried to think, wandering past his own bookshelves crammed with textbooks and sci-fi to lie on his bed.
The funny thing was, he should have agreed with Dad. No one had ever seen any evidence of magic, and according to Mum, there was a whole magical world out there. How could anyone keep something like that a secret in a world of video cameras and spy satellites? More magic? That seemed like a rather suspicious sort of excuse.
Except that some part of Harry was utterly convinced that what his Mum said was true. He was magic... a wizard.
Was it simple ego? What child didn't want to believe they possessed hidden, magic powers? He knew he had an inflated sense of self-importance as others judged it. He'd always vowed to one day justify it by proving himself unique. Of course, he'd figured it would be somewhere in the realm of science. He'd imagined becoming a world renowned biologist, curing cancer and extending lifespans indefinitely. Or going into physics to perfect cold fusion, ending the planet's energy needs and propelling humanity to the stars. Reasonable things. Mostly. Not magic, at any rate.
Maybe his powers of reason had been impaired somehow. He frowned, probing his skull with his fingers as if some wound would present itself. He hadn't hit his head on anything lately... not that he could remember in any case. Would he even remember? There was a scary thought. Harry mentally jumped through some quick mental hoops to confirm that yes, the least complicated answer that fit all the facts is most likely to be the true one, that all claims require evidence and that extraordinary claims require extraordinary evidence, that two plus two still equaled four.
It should have been a clean case for Mum joking, lying or being insane, in ascending order of awfulness. If Mum had sent the letter herself, that would explain how it arrived at the letterbox without a stamp. A little insanity was far, far less improbable than the universe really working like the contents of that letter implied.
What about his mother's other views? Was he any more susceptible to those? He considered her belief that atoms arranged in a particular pattern identified as a "crystal" could somehow destroy bacteria or viruses in his body when touched to his skin... specifically those bacteria or viruses deemed "harmful," opposed to all the beneficial ones... Yes, that he could still rationally reject as a form of wish fulfillment without any evidence to back it up. If the person from Hogwarts came to their house and started bending spoons, he would toss the letter in the trash and think nothing further of it.
But that he was magical... that irrational belief still stayed. And he could think of no evidence to account for it: no moments in his life when he'd exhibited supernatural or unexplainable powers, no hidden talent manifesting in times of great peril or passion. But he still believed he was magic.
Harry rubbed his forehead, grimacing. Don't believe everything you think, Harry reminded himself. So where do you come from, strange little prediction? Why do I believe what I believe?
Usually Harry was pretty good at answering that question, but in this particular case, he had no clue what his brain was thinking. He couldn't remember having a belief so clearly based on faith since he was very young. Some people, unfamiliar with the scientific method or rationalism, seemed to think that science took faith, since no one did every experiment themselves, but rather relied on other scientists or textbooks to tell them what was true or not true.
The problem with this view was that no scientist had "faith" in textbooks, other scientists, or even the scientific method. They had confidence in them. Somewhere, someone was able to do the experiments, verified the results through repeated tests, and then subjected their findings to peer review so others could repeat the experiments. And if he wanted, Harry could take the time and effort to learn the information and repeat the experiment himself. Belief in science relied on the external, not the internal, and thus could be shown to others, taught and learned. He no more had faith in science than he had faith that Dad's car would start tomorrow: he had confidence based on experimentation and observation.
This new belief, however, was not based on external factors. He couldn't describe it to anyone in a way that would make sense. He couldn't demonstrate the belief and have it peer reviewed. It just was.
Harry mentally shrugged. A button calls to be pushed, a handle yearns to be turned, and the thing to do with a testable hypothesis is to go and test it.
He went to his desk, shoved some of the books to the side, and took a piece of lined paper from a drawer to start writing.
Dear Minerva McGonagall
Harry paused, reflecting, then discarded the paper for another, tapping another millimetre of graphite from his mechanical pencil. This called for careful calligraphy.
Dear Deputy Headmistress Minerva McGonagall,
Or Whomsoever It May Concern:
I recently received your letter of acceptance to Hogwarts, addressed to Mr. H. Potter. You may not be aware that my genetic parents, James Potter and Lily Potter (formerly Lily Evans) are dead. I was adopted by Lily's sister, Petunia Evans-Verres, and her husband, Michael Verres-Evans.
I am extremely interested in attending Hogwarts, conditional on such a place actually existing. Only my mother Petunia says she knows about magic, and she can't use it herself. My father is highly skeptical. I myself am uncertain. I also don't know where to obtain any of the books or equipment listed in your acceptance letter.
Mother mentioned that you sent a Hogwarts representative to Lily Potter (then Lily Evans) in order to demonstrate to her family that magic was real, and, I presume, help Lily obtain her school materials. If you could do this for my own family it would be extremely helpful.
Harry James Potter-Evans-Verres.
Harry added their current address, then folded up the letter and put it in an envelope, which he addressed to Hogwarts. Further consideration led him to obtain a candle and drip wax onto the flap of the envelope, into which, using a penknife's tip, he impressed the initials H.J.P.E.V. If he was going to descend into this madness, he was going to do it with style.
Then he opened his door and went back downstairs. His father was sitting in the living-room and reading a book of higher maths to show how smart he was, and his mother was in the kitchen preparing one of his father's favourite meals to show how loving she was. It didn't look like they were talking to one another at all. As scary as arguments could be, not arguing was somehow much worse.
"Mum," Harry said into the unnerving silence, "I'm going to test the hypothesis. According to your theory, how do I send a letter to Hogwarts?"
His mother turned from the sink to look at him uncertainly. "I don't know, I think you 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 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.
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 this. I will use the scientific method even if the result 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 from nearby.
Harry yanked down his hand as if it had caught fire, hiding 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. "Hi Mrs. Figg. I'm just... testing a really silly theory-"
"Did you get your acceptance letter from Hogwarts?"
"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 thinking himself 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."