Harry Potter and the Methods of Rationality

You deliberately tried to hurt Dumbledore's feelings.

He's never tried to hurt you, Harry Potter, not once.

Harry's head dropped into his hands.

Why had Harry said what he'd said, to a sad old ancient wizard who'd fought hard and endured more than anyone should ever have to endure? Even if the old wizard was wrong, did he deserve to be hurt for it, after all that had happened to him? Why was there a part of him that seemed to get angry at the old wizard beyond reason, lashing out at him harder than Harry had ever hit anyone, without thought of moderation once the rage had been raised, only to quiet as soon as Harry left his presence?

Is it because you know Dumbledore won't fight back? That no matter what you say to him, however unfair, he'll never use his own power against you, he'll never treat you the way you treat him? Is this the way you treat people when you know they won't hit back? James Potter's bullying genes, manifesting at last?

Harry closed his eyes.

Like the Sorting Hat speaking inside his head -

What is the real reason for your anger?

What do you fear?

A whirlwind of images seemed to flash through Harry's mind, then, the past Dumbledore weeping into his hands; the present form of the old wizard, standing tall and terrible; a vision of Hermione screaming in her chains, in the metal chair, as Harry abandoned her to the Dementors; and an imagination of a woman with long white hair (had she looked like her husband?) falling amid the flames of her bedroom, as a wand was held upon her and orange light reflected from half-moon glasses.

Albus Dumbledore had seemed to think that Harry would be better at that sort of thing than him.

And Harry knew that he probably would be. He knew the math, after all.

But it was understood, somehow it was understood, that utilitarian ethicists didn't actually rob banks so they could give the money to the poor. The end result of throwing away all ethical constraint wouldn't actually be sunshine and roses and happiness for all. The prescription of consequentialism was to take the action that led to the best net consequences, not actions that had one positive consequence and wrecked everything else along the way. Expected utility maximizers were allowed to take common sense into account, when they were calculating their expectations.

Somehow Harry had understood that, even before anyone else had warned him he'd understood. Before he'd read about Vladimir Lenin or the history of the French Revolution, he'd known. It might have been his earliest science fiction books warning him about people with good intentions, or maybe Harry had just seen the logic for himself. Somehow he'd known from the very beginning, that if he stepped outside his ethics whenever there was a reason, the end result wouldn't be good.

A final image came to him, then: Lily Potter standing in front of her baby's crib and measuring the intervals between outcomes: the final outcome if she stayed and tried to curse her enemy (dead Lily, dead Harry), the final outcome if she walked away (live Lily, dead Harry), weighing the expected utilities, and making the only sensible choice.

She would've been Harry's mother if she had.

"But human beings can't live like that," the boy's lips whispered to the empty classroom. "Human beings can't live like that."

Chapter 83: Taboo Tradeoffs, Aftermath 1

When Padma entered the Transfiguration classroom, she saw that half the class had beaten her there, a strange, deathly silence pervading the room. Harry Potter sat alone in one corner, staring off into some unknown distance, his eyes half-lidded, nearly closed.

Rumor said that the Aurors had discovered that the Defense Professor had Polyjuiced as Granger to fool Malfoy.

Rumor said that Hermione had been bound by the Unbreakable Vow to be Draco Malfoy's slave.

Rumor said that Hermione had gotten the Dementor's Kiss.

But if that were true, Harry Potter wouldn't be sitting there, he would be -

Padma didn't know what General Potter would do. Her mind went blank, trying to think about it.

Even when Professor McGonagall got there, the silence hadn't broken. The Transfiguration Professor walked up to the board without a pause, erased it with a sweep of her hand, and then began to write.

"Today, children," began the calm professional voice of the Transfiguration Professor, just as though nothing out of the ordinary had happened that week, "we shall learn how much effort it takes to sustain a Transfiguration, and why, at your age, you should not even try. The original Form is not gone, only suppressed; and to maintain that suppression -"

"Excuse me," said Padma Patil. She knew her voice was shaking, she knew that she was trembling visibly, but she had to ask. "Excuse me, Professor, what happened with Miss Granger?"

The Transfiguration Professor paused at the board, and turned to look at Padma. The Professor should have looked stern, having been interrupted without a hand being raised, but instead her face was kindly. "You don't already know, Miss Patil? I expected that rumor would have spread."

"There's too many rumors," said Padma. "I don't know what's true."

Morag MacDougal raised her hand, then said without waiting to be called, "I told you, Padma, what's true is that the Wizengamot found Granger guilty and ordered her to get the Dementor's Kiss and they brought in the Dementor and Harry Potter glued it to the ceiling and wouldn't let it down until -"

"Oh, dear Merlin," said Professor McGonagall, her expression growing sharp, but then she visibly calmed