Eliezer Yudkowsky - Harry Potter and the Methods of Rationality

Professor Quirrell’s eyebrows had climbed toward his hairline. His voice was less soft, had something of his normal sharpness, as he said, “I forbid you from doing that again.”

“I wondered if you’d say that,” Harry said. He swallowed again. “But this unicorn is already, already doomed, so you might as well take it, Professor…”

“Why have you done this?”

If the Defense Professor really didn’t understand that, he was slower on the uptake than anyone Harry had ever met. “I kept thinking there was nothing I could do,” Harry said. “I got tired of thinking it.”

Professor Quirrell closed his eyes. His head leaned back into the pillow. “You were lucky,” the Defense Professor said in a soft voice, “that a unicorn in Transfigured form… did not set off the Hogwarts wards, as a strange creature… I shall have to… take this outside the grounds, to make use of it… but that can be managed. I shall tell them that I wish to look upon the lake… I will ask you to sustain the Transfiguration before you go, and it should last long enough, after that… and with my last strength, dispel whatever death-alarms were placed to watch over the herd… which, the unicorn being not yet dead, but only Transfigured, will not yet have triggered… you were very lucky, Mr. Potter.”

Harry nodded. He started to speak, then stopped again. Words seemed to stick in his throat once more.

You already calculated the expected utilities, if it works, if it goes wrong. You assigned probabilities, you multiplied, and then you threw out the answer and went with your new gut feeling, which was the same. So say it.

“Do you know,” Harry said unsteadily, “of any way at all, by which your life might be saved?”

The Defense Professor’s eyes opened. “Why… do you ask me that, boy?”

“There’s… a spell I heard of, a ritual—”

“Be silent,” said the Defense Professor.

An instant later a snake lay in the bed.

Even the snake’s eyes were dull.

It did not rise.

“ Sspeak on, ” hissed that snake, its flickering tongue its only motion.

“There is… there iss a ritual, I heard of from the sschoolmasster, by which he thinkss the Dark Lord might have lived on. It iss called —”and Harry stopped, as he realized that he did know how to say the word in Parseltongue. “Horcrux. It requiress a death, I have heard. But if you are dying in any casse, you might try to adapt the ritual, even at great rissk for the new sspell, sso that it can be done with a different ssacrifice. It would change the whole world, if you ssucceed — though I don't know anything about the sspell — the sschoolmasster thought it tore off a piece of ssoul, though I don't ssee how that could be true —”

The snake was hissing laughter, strange sharp laughter, almost hysterical. “ You tell me of that sspell? Me? You musst learn more caution in the future, boy. But it matterss not. I learned of the horcrux sspell ssince long ago. It iss meaninglesss. ”

“Meaningless?” Harry said aloud in surprise. “ Would be pointlesss sspell from beginning, if ssoulss exissted. Tear piece of ssoul? That iss lie. Missdirection to hide true ssecret. Only one who doess not believe in common liess will reasson further, ssee beneath obsscuration, realisse how to casst sspell. Required murder iss not ssacrificial ritual at all. Ssudden death ssometimes makess ghosst, if magic burssts and imprintss on nearby thing. Horcrux sspell channelss death-bursst through casster, createss your own ghosst insstead of victim'ss, imprintss ghosst in sspecial device. Ssecond victim pickss up horcrux device, device imprintss your memoriess into them. But only memoriess from time horcrux device wass made. You ssee flaw? ”

The burning sensation was back in Harry’s throat. “ No continuity of —” there wasn’t a snake word for consciousness “— sself, you would go on thinking after making the horcrux, then sself with new memoriess diess and iss not resstored —”

“ Yess, you do ssee. Alsso Merlin'ss Interdict preventss powerful sspells from passing through ssuch a device, ssince it iss not truly alive. Dark Wizardss who think to return thuss are weaker, eassily disspatched. None have perssissted long by ssuch meanss. Perssonalitiess change, mix with victim'ss. Death iss not truly gainssaid. Real sself is losst, as you ssay. Not to my pressent tasste. Admit I conssidered it, long ago. ”

A man was lying in the infirmary bed once more. The Defense Professor breathed, then made a wretched coughing sound.

“Can you give me a full recipe for the spell?” Harry said, after a moment’s deliberation. “There might be some way to improve on the flaws, with enough research. Some way to do it ethically and have it work.” Like doing the transfer into a clone body with a blank brain, instead of an innocent victim, which might also improve the fidelity of the personality transfer… though that still left the other problems.

Professor Quirrell made a short sound, under his breath, that might have been laughter. “You know, boy,” Professor Quirrell whispered, “I had thought… to teach you everything… the seeds of all the secrets I knew… from one living mind to another… so that later, when you found the right books, you would be able to understand… I would have passed on my knowledge to you, my heir… we would have begun as soon as you asked me… but you never asked.”

Even the grief surrounding by Harry like thick water gave way to that, to the sheer magnitude of the missed opportunity. “I was supposed to—? I didn’t know I was supposed to—!”

Another coughing chuckle. “Ah yes… the unknowing Muggleborn… in heritage if not in blood… that is you. But I thought… better of it… that you should not walk my path… it was not a good path, in the end.”

“It’s not too late, Professor!” Harry said. A part of Harry yelled that he was being selfish, and then another part shouted that down; there would be other people to help.

“Yes, it is too late… and you shall not… persuade me otherwise… I have… thought better of it… as I said… I am too full… of secrets better left unknown… look at me. ”

Harry looked, almost despite himself.

He saw a still-unwrinkled face, looking old and pained, beneath a head rapidly losing its hair, even the sides looking wispy now; Harry saw a face he’d always thought was sharp, now revealed as thin, muscle and fat fading away from the face, as from the arms beneath it, like the

skeletal form of Bellatrix Black he’d seen in Azkaban— Harry’s head wrenched aside, unthinkingly.

“You see,” whispered the Professor. “I dislike to sound cliched… Mr. Potter… but the truth is… the Arts called Dark… really are not good for a person… in the end.”

Professor Quirrell breathed in, breathed out. There was quiet for a time in the infirmary, the two of them watched only by the elaborately ornamented stone of the walls.

“Is there anything left… unsaid between us?” said Professor Quirrell. “I am not dying today… mind you… not right now… but I do not know how long… I shall be able to converse.”

“There’s,” Harry said, swallowed again. “There’s a lot of things, way too many things, but… it might be the wrong thing to ask, but I don’t

want—this one question unanswered—snake?” A snake lay on the bed.

“ I learned how the Killing Cursse workss. Requiress true hate to casst, not much hate, but musst want target dead, they ssay. In prisson with life-eaterss, you casst Killing Cursse at guard — ssaid you did not want him dead — wass that lie? Here, now, at thiss disstance — you may sspeak truth — even if you fear it reflectss poorly on you — it sshould not matter now, teacher. I wissh to know. Musst know. Will not abandon you, either way. ”