Eliezer Yudkowsky - Harry Potter and the Methods of Rationality

Harry blinked in surprise as his mind finally made the obvious connection.

... that meant that as soon as he learned a spell to temporarily alter his own sense of humor, he could make anything happen, by making it so that he would only find that one thing surprising enough to do a spit-take, and then drinking a can of Comed-Tea.

Well that was a short little journey to godhood. Even I expected this to take longer than my first day of school.

Come to think of it, he had also completely wrecked Hogwarts within ten minutes flat of getting Sorted.

Harry did feel a certain amount of regret about this - Merlin knew what an insane Headmaster was going to do to his next seven years of schooling - but he couldn't help feeling a twinge of pride, too.

Tomorrow. No later than tomorrow at the very latest he was going to stop walking down the path that led to Dark Lord Harry. A prospect which was sounding scarier by the minute.

And yet also, somehow, increasingly attractive. Part of his mind was already visualising the minions' uniforms.

"Eat," the older student sitting next to him growled, and jabbed Harry in the ribs. "Don't think. Eat."

Harry automatically started loading up his plate with whatever was in front of him, blue sausages with tiny glowing bits, whatever.

"What were you thinking about, the Sorting -" began to say Padma Patil, one of the other first-year Ravenclaws.

"No pestering during mealtimes!" chorused at least three people. "House Rule!" added another. "Otherwise we'd all starve around here."

Harry was finding himself really, really hoping that his clever new idea didn't actually work. And that the Comed-Tea worked some other way and didn't actually have the omnipotent power to alter reality. It wasn't that he didn't want to be omnipotent. It was that he just couldn't bear the thought of living in a universe that really worked like that. There was something undignified about ascending through the clever use of fizzy drinks.

But he was going to test it experimentally.

"You know," said the older student next to him in a quite pleasant tone, "we have a system for forcing people like you to eat, would you like to find out what it is?"

Harry gave up and started eating his blue sausage. It was quite good, especially the glowing bits.

Dinner passed with surprising rapidity. Harry tried to sample at least a little of all the weird new foods he saw. His curiosity couldn't stand the thought of not knowing how something tasted. Thank goodness this wasn't a restaurant where you had to order only one thing and you never found out what all the other things on the menu tasted like. Harry hated that, it was like a torture chamber for anyone with a spark of curiosity: Find out about only one of the mysteries on this list, ha ha ha!

Then it was time for dessert, which Harry had completely forgotten to leave room for. He gave up after sampling a small bit of treacle tart. Surely all these things would pass around at least once again over the course of the school year.

So what was on his to-do list, besides the ordinary school things?

To-do 1. Research mind-alteration charms so you can test the Comed-Tea and see whether you actually did figure out a path to omnipotence. Actually, just research every kind of mind magic you can find. Mind is the foundation of our power as humans, any kind of magic that affects it is the most important sort of magic there is.

To-do 2. Actually this is To-do 1 and the other is To-do 2. Go through the bookshelves of the Hogwarts and Ravenclaw libraries, familiarising yourself with the system and making sure you've at least read all the book titles. Second pass: read all tables of contents. Coordinate with Hermione who has a much better memory than you. Find out if there's an interlibrary loan system at Hogwarts and see if the two of you, especially Hermione, can visit those libraries too. If other Houses have private libraries, figure out how to access legally or sneak in.

Option 3a: Swear Hermione to secrecy and try to start researching 'From Slytherin to Slytherin: if you would seek my secrets, speak to my snake.' Problem: This sounds highly confidential and it could take quite a while to randomly run across a book containing a hint.

To-do 0: Check out what sort of information-search-and-retrieval spells exist, if any. Library magic isn't as ultimately important as mind magic but it has a much higher priority.

Option 3b: Look for a spell to magically bind Draco Malfoy to secrecy, or magically verify the sincerity of Draco's promise to keep a secret (Veritaserum?), and then ask him about Slytherin's message...

Actually... Harry had a pretty bad feeling about option 3b.

Now that Harry thought about it, he didn't feel all that great about option 3a, either.

Harry's thoughts flashed back to possibly the worst moment of his life to date, those long seconds of blood-freezing horror beneath the Hat, when he thought he'd already failed. He'd wished then to fall back just a few minutes in time and change something, anything before it was too late...

And then it had turned out to not be too late after all.

Wish granted.

You couldn't change history. But you could get it right to start with. Do something differently the first time around.

This whole business with seeking Slytherin's secrets... seemed an awful lot like the sort of thing where, years later, you would look back and say, 'And that was where it all started going wrong.'

And he would wish desperately for the ability to fall back through time and make a different choice...

Wish granted. Now what?

Harry slowly smiled.

It was a rather counterintuitive thought... but...

But he could, there was no rule saying he couldn't, he could just pretend he'd never heard that little whisper. Let the universe go on in exactly the same way it would have if that one critical moment had never occurred. Twenty years later, that was what he would desperately wish had happened twenty years ago, and twenty years before twenty years later happened to be right now. Altering the distant past was easy, you just had to think of it at the right time.

Or... this was even more counterintuitive... he could even inform, oh, say, Professor McGonagall, instead of Draco or Hermione. And she could get a few good people together and get that little extra spell taken off the Hat.

Why, yes. That sounded like a remarkably good idea once Harry had actually thought of it.

So very obvious in retrospect, and yet somehow, Option 3c and Option 3d just hadn't occurred to him.

Harry awarded himself +1 point on his anti-Dark-Lord-Harry program.

It had been an awfully cruel prank the Hat had played on him, but you couldn't argue with the results on consequentialist grounds. It certainly did give him a better idea of the victim's perspective, though.

To-do 4: Apologise to Neville Longbottom.

Okay, he was on a roll here, now he just had to keep it up. In every day, in every way, I'm getting Lighter and Lighter...

People around Harry had also mostly stopped eating at this point, and the dessert serving dishes began to vanish, and the used plates.

When all the plates were gone, Dumbledore once again stood up from his seat.

Harry couldn't help but feel the urge to drink another Comed-Tea.

You've GOT to be kidding, Harry thought at that piece of himself.

But the experiment didn't count if it wasn't replicated, did it? And the damage was already done, wasn't it? Didn't he want to see what would happen this time? Wasn't he curious? What if he got a different result?