Harry Potter and the Methods of Rationality

spending money for books could be excused as well. Though you might want to hold off for a time. Hogwarts has quite a large library on magical subjects. And the tower in which, I strongly suspect, you will be living, has a more broad-ranging library of its own. Any book you bought now would probably be a duplicate."

Harry nodded, and they walked on.

"Don't get me wrong, it's a great distraction," Harry said as his head kept swivelling, "probably the best distraction anyone has ever tried on me, but don't think I've forgotten about our pending discussion."

Professor McGonagall sighed. "Your parents - or your mother at any rate - may have been very wise not to tell you."

"So you wish that I could continue in blissful ignorance? There is a certain flaw in that plan, Professor McGonagall."

"I suppose it would be rather pointless," the witch said tightly, "when anyone on the street could tell you the story. Very well."

And she told him of He-Who-Must-Not-Be-Named, the Dark Lord, Voldemort.

"Voldemort?" Harry whispered. It should have been funny, but it wasn't. The name burned with a cold feeling, ruthlessness, diamond clarity, a hammer of pure titanium descending upon an anvil of yielding flesh. A chill swept over Harry even as he pronounced the word, and he resolved then and there to use safer terms like You-Know- Who.

The Dark Lord had raged upon wizarding Britain like a wilding wolf, tearing and rending at the fabric of their everyday lives. Other countries had wrung their hands but hesitated to intervene, whether out of apathetic selfishness or simple fear, for whichever was first among them to oppose the Dark Lord, their peace would be the next target of his terror.

(The bystander effect, thought Harry, thinking of Latane and Darley's experiment which had shown that you were more likely to get help if you had an epileptic fit in front of one person than in front of three. Diffusion of responsibility, everyone hoping that someone else would go first.)

The Death Eaters had followed in the Dark Lord's wake and in his vanguard, carrion vultures to pick at wounds, or snakes to bite and weaken. The Death Eaters were not as terrible as the Dark Lord, but they were terrible, and they were many. And the Death Eaters wielded more than wands; there was wealth within those masked ranks, and political power, and secrets held in blackmail, to paralyse a society trying to protect itself.

An old and respected journalist, Yermy Wibble, called for increased taxes and conscription. He shouted that it was absurd for the many to cower in fear of the few. His skin, only his skin, had been found nailed to the newsroom wall that next morning, next to the skins of his wife and two daughters. Everyone wished for something more to be done, and no one dared take the lead to propose it. Whoever stood out the most became the next example.

Until the names of James and Lily Potter rose to the top of that list.

And those two might have died with their wands in their hands and not regretted their choices, for they were heroes; but for that they had an infant child, their son, Harry Potter.

Tears were coming into Harry's eyes. He wiped them away in anger or maybe desperation, I didn't know those people, not really, they aren't my parents now, it would be pointless to feel so sad for them -

When Harry was done sobbing into the witch's robes, he looked up, and felt a little bit better to see tears in Professor McGonagall's eyes as well.

"So what happened?" Harry said, his voice trembling.

"The Dark Lord came to Godric's Hollow," Professor McGonagall said in a whisper. "You should have been hidden, but you were betrayed. The Dark Lord killed James, and he killed Lily, and he came in the end to you, to your cot. He cast the Killing Curse at you, and that was where it ended. The Killing Curse is formed of pure hate, and strikes directly at the soul, severing it from the body. It cannot be blocked, and whomever it strikes, they die. But you survived. You are the only person ever to survive. The Killing Curse rebounded and struck the Dark Lord, leaving only the burnt hulk of his body and a scar upon your forehead. That was the end of the terror, and we were free. That, Harry Potter, is why people want to see the scar on your forehead, and why they want to shake your hand."

The storm of weeping that had washed through Harry had used up all his tears; he could not cry again, he was done.

(And somewhere in the back of his mind was a small, small note of confusion, a sense of something wrong about that story; and it should have been a part of Harry's art to notice that tiny note, but he was distracted. For it is a sad rule that whenever you are most in need of your art as a rationalist, that is when you are most likely to forget it.)

Harry detached himself from Professor McGonagall's side. "I'll - have to think about this," he said, trying to keep his voice under control. He stared at his shoes. "Um. You can go ahead and call them my parents, if you want, you don't have to say 'genetic parents' or anything. I guess there's no reason I can't have two mothers and two fathers."

There was no sound from Professor McGonagall.

And they walked together in silence, until they came before a great white building with vast bronze doors, and carven words above saying Gringotts Bank.

Chapter 4: The Efficient Market Hypothesis

Disclaimer: J. K. Rowling is watching you from where she waits, eternally in the void between worlds.

A/N: As others have noted, the novels seem inconsistent in the apparent purchasing power of a Galleon; I'm picking a consistent value and sticking with it. Five pounds sterling to the Galleon doesn't square with seven Galleons for a wand and children using hand-me-down wands.

"World domination is such an ugly phrase. I prefer to call it world optimisation."

Heaps of gold Galleons. Stacks of silver Sickles. Piles of bronze Knuts.