Harry Potter and the Methods of Rationality

Harry's mouth gaped open in speechless shock as he searched frantically for something to say to this. That is so completely not what I am about!

But he could see that the other students were starting to believe it. Harry's mind was flipping through possible denials and not finding anything that could stand up against the authoritative voice of Professor Quirrell. The best Harry had come up with was "I'm not a psychopath, I'm just very creative" and that sounded kind of ominous. He needed to say something unexpected, something that would make people stop and reconsider -

"And now," Professor Quirrell said. "Mr. Potter. Fire."

Nothing happened, of course.

"Ah, well," said Professor Quirrell. He sighed. "I suppose we must all start somewhere. Mr. Potter, select any student you please for a Simple Strike Hex. You will do so before I dismiss your class for the day. If you do not, I will begin deducting House points, and I will keep on deducting them until you do."

Harry carefully raised his wand. He had to do that much, or Professor Quirrell might start deducting House points right away.

Slowly, as though on a roasting platter, Harry turned to face the Slytherins.

And Harry's eyes met Draco's.

Draco Malfoy didn't look the slightest bit afraid. The blonde-haired boy wasn't giving any visible sign of assent such as Harry had given Hermione, but then he could hardly be expected to do so. The other Slytherins would think that rather odd.

"Why the hesitation?" said Professor Quirrell. "Surely there's only one obvious choice."

"Yes," Harry said. "Only one obvious choice."

Harry twisted the wand and said "Ma-ha-su!"

There was complete silence in the classroom.

Harry shook his left arm, trying to get rid of the lingering sting.

There was more silence.

Finally Professor Quirrell sighed. "Yes, quite ingenious, but there was a lesson to be taught and you dodged it. One point from Ravenclaw for showing off your own cleverness at the expense of the actual goal. Class dismissed."

And before anyone else could say anything, Harry sang out:

"Just kidding! RAVENCLAW!"

There was silence for a brief moment after that, a sound of people thinking, and then the murmurs started and rapidly rose to a roar of conversation.

Harry turned towards Professor Quirrell, the two of them needed to talk -

Quirrell had slumped over and was trudging back to his chair.

No. Not acceptable. They really needed to talk. Stuff the zombie act, Professor Quirrell would probably wake up if Harry poked him a couple of times. Harry started forward -

WRONG

DON'T

BAD IDEA

Harry swayed and stopped in his tracks, feeling dizzy.

And then a flock of Ravenclaws descended on him and the discussions began.

Chapter 17: Locating the Hypothesis

You have always been J. K. Rowling.

Historical note: In the Roman calendar, the "Ides" of a month referred to the 15th day of March, May, July, and October, and to the 13th day of all other months.

"You start to see the pattern, hear the rhythm of the world."

Thursday.

If you wanted to be specific, 7:24am on Thursday morning.

Harry was sitting on his bed, a textbook lying limp in his motionless hands.

Harry had just had an idea for a truly brilliant experimental test.

It would mean waiting an extra hour for breakfast, but that was why he had cereal bars. No, this idea absolutely positively had to be tested right away, immediately, now.

Harry set the textbook aside, leapt out of bed, raced around his bed, yanked out the cavern level of his trunk, ran down the stairs, and started moving boxes of books around. (He really needed to unpack and get bookcases at some point but he was in the middle of his textbook reading contest with Hermione and falling behind so he hadn't had time.)

Harry found the book he wanted and raced back upstairs.

The other boys were getting ready to go down to breakfast in the Great Hall and start the day.

"Excuse me can you do something for me?" said Harry. He was flipping through the book's index as he spoke, found the page with the first ten thousand primes, flipped to that page, and thrust the book at Anthony Goldstein. "Pick two three-digit numbers from this list. Don't tell me what they are. Just multiply them together and tell me the product. Oh, and can you do the calculation twice to double-check? Please make really sure you've got the right answer, I'm not sure what's going to happen to me or the universe if you make a multiplication error."

It said a lot about what life in that dorm had been like over the past few days that Anthony didn't even bother saying anything like "Why'd you suddenly flip out?" or "That seems really weird, what are your reasons for asking?" or "What do you mean, you're not sure what's going to happen to the universe?"