Harry Potter and the Methods of Rationality

Her voice halted.

"Then we'll study together," Harry said. His voice was even colder now.

"Um, bye for now, then," Hermione said, and she quickly went out of the room and shut the door behind her.

Sometimes Harry hated having a dark side, even when he was inside it.

And the part of him that had thought exactly the same thing as Hermione, that no, children couldn't do what grownups couldn't, was saying all the things that Hermione had been too frightened to say, like, That's one hell of a difficult challenge you just grabbed for yourself and boy are you going to end up with egg on your face this time and at least this way you'll know you've failed.

And the part of him that didn't enjoy losing replied, in a very cold voice, Fine, you can shut up and watch.

It was almost lunchtime, and Harry didn't care. He hadn't even bothered grabbing a snack bar from his pouch. His stomach could stand a little starving.

The wizarding world was tiny, they didn't think like scientists, they didn't know science, they didn't question what they'd grown up with, they hadn't put protective shells on their time machines, they played Quidditch, all of magical Britain was smaller than a small Muggle city, the greatest wizarding school only educated up to the age of seventeen, silly wasn't challenging that at eleven, silly was assuming wizards knew what they were doing and had already exhausted all the low- hanging fruit a scientific polymath would see.

Step One had been to make a list of every magical constraint Harry could remember, all the things you supposedly couldn't do.

Step Two, mark the constraints that seemed to make the least sense from a scientific perspective.

Step Three, prioritize constraints that a wizard would be unlikely to question if they didn't know science.

Step Four, come up with avenues for attacking them.

Hermione still felt a little shaky as she sat down next to Mandy at the Ravenclaw table. Hermione's lunch had two fruits (tomato slices and peeled tangerines), three vegetables (carrots, carrots, and more carrots), one meat (fried Diricawl drumsticks whose unhealthy coating she would carefully remove), and one little piece of chocolate cake that she would earn by eating the other parts.

It hadn't been as bad as Potions class, sometimes she still had nightmares about that. But this time she had made it happen and she'd felt like its target. Just for a moment, before the terrible cold darkness looked away and said it wasn't angry with her, because it hadn't wanted to scare her.

And she still had that feeling like she'd missed something earlier, something really important.

But they hadn't violated any of the rules of Transfiguration... had they? They hadn't made any liquids, any gases, they hadn't taken orders from the Defense Professor...

The pill! That had been something to be eaten!

...well, no, nobody would just eat a pill lying around, it hadn't worked actually, they could have just Finite Incantatemed it if it had, but she would still have to tell Harry about that and make sure they didn't mention it in front of Professor McGonagall, in case they were never allowed to study Transfiguration again...

Hermione was starting to get a really sick feeling in her stomach. She pushed back her plate from the table, she couldn't eat lunch like this.

And she closed her eyes and began to mentally recite the rules of Transfiguration.

"I will never Transfigure anything into liquid or gas."

"I will never Transfigure anything that looks like food or anything else that goes inside a human body."

No, they really shouldn't have tried to Transfigure the pill, or they should've at least realized... she'd been so caught up in Harry's brilliant idea that she hadn't thought...

The sick feeling in Hermione's stomach was getting worse. There was a feeling in her mind of something hovering just on the edge of recognition, a perception about to invert itself, a young woman about to become a crone, a vase about to become two faces...

And she went on remembering the rules of Transfiguration.

Harry's knuckles had gone white on his wand by the time he stopped trying to Transfigure the air in front of his wand into a paperclip. It wouldn't have been safe to Transfigure the paperclip into gas, of course, but Harry didn't see any reason why it would be unsafe the other way around. It just wasn't supposed to be possible. But why not? Air was as real a substance as anything else...

Well, maybe that limitation did make sense. Air was disorganized, all the molecules constantly changing their relation to each other. Maybe you couldn't impose a new form on substance unless the substance was staying still long enough for you to master it, even though the atoms in solids were also constantly vibrating all the time...

The more Harry failed, the colder he felt, the clearer everything seemed to become.

All right. Next on the list.

You could only Transfigure whole objects as wholes. You couldn't Transfigure half a match into a needle, you had to Transfigure the whole thing. Back when Harry had been trapped in that classroom by Draco, it had been the reason he couldn't just Transfigure a thin cylindrical cross- section of the walls into sponge, and punch out a chunk of stone large enough for him to fit through the hole. He would have needed to impose a new form on the whole wall, and maybe a whole section of Hogwarts, just in order to change that little cross-section.

And that was ridiculous.