Eliezer Yudkowsky - Harry Potter and the Methods of Rationality

“Something went wrong,” Harry said. “Something that blew off the top of the Potters’ home in Godric’s Hollow, gave me the scar on my forehead, and left your burnt body behind.”

Professor Quirrell nodded. His hands had slowed in their Potions work. “The resonance in our magic,” Professor Quirrell said quietly. “When I had shaped the baby’s spirit to be like my own…”

Harry remembered the moment in Azkaban when Professor Quirrell’s Killing Curse had collided with his Patronus. The burning, tearing agony in his forehead, like his head had been about to split in half.

“I cannot count how many times I have thought of that night, rehearsing my mistake, thinking of wiser things I should have done,” said Professor Quirrell. “I later decided that I should have thrown my wand from my hand and changed into my Animagus form. But that night… that night, I instinctively tried to control the chaotic fluctuations in my magic, even as I felt myself burning up from inside. That was the wrong decision, and I failed. So my body was destroyed, even as I overwrote the infant Harry Potter’s mind; either of us destroying all but a remnant of the other. And then…” Professor Quirrell’s expression was controlled. “And then, when I regained consciousness inside my horcruxes, it turned out that my great creation did not work as I had hoped. I should have been able to float free of my horcruxes and possess any victim that consented to me, or that was too weak to refuse me. That was the part of my great creation that failed my intent. As with the original horcrux spell, I would only be able to enter a victim who contacted the physical horcrux… and I had hidden my unnumbered horcruxes in places where nobody would ever find them. Your instinct is correct, boy, this would not be a good time to laugh. ” Harry stayed very quiet.

The Potions-making had come to a temporary pause, a space where no ingredients were added while the cauldron simmered for a time. “I spent most of my time looking at the stars,” Professor Quirrell said, his voice quieter now. The Defense Professor had turned from the potion, staring at the white-illuminated walls of the room. “My remaining hope was the horcruxes I had hidden in the hopeless idiocy of my youth. Imbuing them into ancient lockets, instead of anonymous pebbles; guarding them beneath wells of poison in the center of a lake of Inferi, instead of portkeying them into the sea. If someone found one of those, and penetrated their ridiculous protections… but that seemed like a distant hope. I was not sure I would ever be embodied again. Yet at least I was immortal. The worst of all fates had been averted, my great creation had done that much. I had little left to hope for, and little left to fear. I decided that

I would not go insane, since there seemed to be no advantage in it. Instead, I gazed out at the stars and thought, as the Sun slowly diminished behind me. I reflected on the errors of my past life; they were many, in that hindsight. In my imagination I constructed powerful new rituals I might attempt, if I was free to use my magic once more, and yet confident of my immortality. I contemplated ancient riddles at greater length than before, for all that I had once thought myself patient. I knew that if I won free, I would be more powerful by far than in my previous life; but

I mostly did not expect that to happen.” Professor Quirrell turned back to the potion. “Nine years and four months after that night, a wandering adventurer named Quirinus Quirrell won past the protections guarding one of my earliest horcruxes. The rest you know. And now, boy, you may say what we both know you are thinking.”

“Um,” Harry said. “It doesn’t seem like a very smart thing to say—”

“Indeed, Mr. Potter. It is not a clever thing to say to me. Not even a little. Not in the slightest. But I know you’re thinking it, and you will go on thinking it and I will go on knowing that until you say it. So speak.”

“So. Um. I realise that this is something that is more obvious in hindsight than in foresight, and I’m certainly not suggesting that you try to correct the error now, but if you are a Dark Lord and you happen to hear about a child who has been prophesied to defeat you, there is a certain spell which is unblockable, unstoppable, and works every single time on anything with a brain—”

“ Yes thank you Mr. Potter that thought occurred to me several times over the next nine years. ” Professor Quirrell picked up another bellflower and began crumbling it in his bare fist. “I made that principle the centerpiece of my Battle Magic curriculum after I learned its centrality the hard way. It was not the first Rule on the younger Tom Riddle’s list. It is only by harsh experience that we learn which principles take priority over which other principles; as mere words they all sound equally persuasive. In retrospect it would have been better if I had sent Bellatrix to the Potters’ home in my place; but I had a Rule telling me that for such matters I must go myself and not try sending a trusted lieutenant. Yes, I considered the Killing Curse; but I wondered if casting the Killing Curse at an infant would somehow cause the curse to bounce off and hit me, thus fulfilling the prophecy. How was I to know?”

“So use an axe, it’s hard to get a prophecy-fulfilling spell backfire out of an axe,” Harry said and then shut up.

“I decided the safest path was to try to fulfill the prophecy on my own terms,” Professor Quirrell said. “Needless to say, the next time I hear a prophecy I do not like, I will tear it apart at every possible point of intervention , rather than trying to play along.” Professor Quirrell was crushing a rose as though to squeeze the juice out of it, still using his bare fist. “And now everyone thinks the Boy-Who-Lived is somehow immune to the Killing Curse, even though Killing Curses do not ruin houses or leave burnt bodies behind them, because it has not occurred to them that Lord Voldemort would ever use any other spell. ”

Harry again stayed quiet. It had occurred to Harry that there was another obvious way that Lord Voldemort could have avoided his mistake. Something that might perhaps be easier to see given a Muggle upbringing, instead of the wizarding way of looking at things.

Harry had not yet decided whether to tell Professor Quirrell about his thought; there were both pros and cons to pointing out that particular error.

After a time Professor Quirrell picked up the next Potions ingredient, a strand of what looked like unicorn hair. “I tell you this as a caution,” said Professor Quirrell. “Do not expect me to be delayed another nine years, if you somehow destroy this body of mine. I set horcruxes in better places at once, and now even that is unnecessary. Thanks to you, I learned where to find the Resurrection Stone. The Resurrection Stone does not bring back the dead, of course; but it holds a more ancient magic than my own for projecting the seeming of a spirit. And since I am one who has defeated death, Cadmus’s Hallow acknowledged me its master, and answered all my will. I have now incorporated it into my great creation.” Professor Quirrell smiled slightly. “I had many years earlier considered making that device a horcrux, but decided against it at the time, since I realized that the ring had magic of unknown nature… ah, such ironies does life play upon us. But I digress. You , boy, you brought that about, you freed my spirit to fly where it pleases and seduce the most opportune victim, by being too casual with your secrets. It is a catastrophe for any who oppose me, and you wrought it with one finger drawing wetness on a tea-saucer. This world will be a safer place for all, if you learn the rectitude that wizardborns absorb in childhood. And all thiss that I have jusst said iss the truth. ”