Eliezer Yudkowsky - Harry Potter and the Methods of Rationality

“Hm…” Professor Quirrell said. “Possibly… yes, there is a certain plausibility to it. Using this setting of the Mirror to show people their heart’s desires… Albus Dumbledore would see himself reunited with his family. He would see himself united with them in death, wanting to die himself rather than wishing for them to be returned to life. His brother Aberforth, his sister Ariana, his parents Kendra and Percival… it would be Aberforth to whom Dumbledore gave the Stone, I think. Would the Mirror recognize that Aberforth particularly had been given the Stone? Or will any person’s dead relative do, if that person believes their relative’s spirit would give them back the Stone?” Professor Quirrell was pacing in a short circle, keeping well away from Harry and the Mirror as he moved. “But all this is only one idea. Let us devise another.”

Harry began to tap his cheek, then stopped abruptly as he realized where he’d picked up that gesture. “What if Perenelle is the one who put the Stone in here? Maybe she keyed the Mirror to give the Stone only to the person who put it in originally.”

“Perenelle has lived this long by knowing her limitations,” said Professor Quirrell. “She does not overestimate her own intellect, she is not prideful, if that were so she would have lost the Stone long ago. Perenelle will not try to think of a good Mirror-rule herself, not when Master Flamel can leave the matter in Dumbledore’s wiser hands… but the rule of only returning the Stone to the one who remembers placing it, also works if Dumbledore himself has placed the Stone. It would be a hard rule to bypass, since I cannot simply Confund someone into believing that they put in the Stone… I would have to create a false Stone, and a false Mirror, and arrange the drama…” Professor Quirrell was frowning, now. “But it is still something that Dumbledore would imagine Voldemort being able to arrange, given time. If at all possible, Dumbledore will want to make the key to the Mirror a state of mind he thinks I cannot arrange in a pawn— or a rule that Dumbledore thinks Voldemort can never comprehend, such as a rule involving the acceptance of one’s own death. That is why I considered your previous idea plausible.” Then Harry had an idea.

He was not sure if it was a good idea.

…it wasn’t like Harry had a lot of choice here.

“Arguendo,” Harry said. “We’re not sure what’s necessary to retrieve the Stone. But a sufficient condition should involve Albus Dumbledore, or maybe someone else, in a state of mind where they believe that the Dark Lord has been defeated, that the threat is over, and that it is time to take out the Stone and give it back to Nicholas Flamel. We aren’t sure which part of that person’s state of mind, let’s say Dumbledore’s, will be the necessary part that he thinks Lord Voldemort can’t understand or duplicate; but under those conditions Dumbledore’s entire state of mind will be sufficient. ”

“Reasonable,” said Professor Quirrell. “So?”

“The corresponding strategy,” Harry said carefully, “is to mimic Dumbledore’s state of mind under those conditions, in as much detail as possible, while standing in front of the mirror. And this state of mind must have been produced by internal forces, not external ones.”

“But how are we to get that without Legilimency or the Confundus Charm, both of which would certainly be external—ha. I see. ” Professor Quirrell’s ice-pale eyes were suddenly piercing. “You suggest that I Confund myself, as you cast that hex upon yourself during your first day in Battle Magic. So that it is an internal force and not an external one, a state of mind that comes about through only my own choices. Say to me whether you have made this suggestion with the intention of trapping me, boy. Say it to me in Parseltongue.”

“ Mymindthatyouasskedtodevissesstrategymayperhapsshavebeeninfluenced by ssuch an intent—who knowss? Knew you would be ssusspiciouss, assk thiss very question. Decission is up to you, teacher. I know nothing you do not know, about whether thiss iss likely to trap you. Do not call it betrayal by me if you choosse thiss for yoursself, and it failss. ” Harry felt a strong impulse to smile, and suppressed it.

“Lovely,” said Professor Quirrell, who was smiling. “I suppose there are some threats from an inventive mind that even questioning in Parseltongue cannot neutralize.”

Harry put on the Cloak of Invisibility, at Professor Quirrell’s orders, to sstop the man who sshall believe himsself to be sschoolmasster from sseeing you, as Professor Quirrell said in Parseltongue.

“Wearing the Cloak or no, you will stand in range of the Mirror yourself,” Professor Quirrell said. “If a gush of lava comes forth, you will also burn. I feel that much symmetry should apply.”

Professor Quirrell pointed to a spot near the right of the door through which they’d entered the room, before the Mirror and well back of it. Harry, wearing the Cloak, went to where Professor Quirrell had pointed him, and did not argue. It was increasingly unclear to Harry whether both Riddles dying here would be a bad thing, even with hundreds of other student hostages at stake. For all of Harry’s good intentions, he’d mostly shown himself so far to be an idiot, and the returned Lord Voldemort was a threat to the entire world.

(Though either way, Harry couldn’t see Dumbledore doing the lava thing. Dumbledore was probably sufficiently angry at Voldemort to discard his usual restraint, but lava wouldn’t permanently stop an entity that

Dumbledore believed to be a discorporate soul.)

Then Professor Quirrell pointed with his wand, and a shimmering circle appeared around where Harry was standing on the floor. This, Professor Quirrell said, would soon become a Greater Circle of Concealment, by which nothing within that circle could be heard or seen from the outside. Harry would not be able to make himself apparent to the false Dumbledore by taking off the Cloak, nor by shouting.

“You will not cross this circle once it is active,” Professor Quirrell said. “That would cause you to touch my magic, and while Confunded I might not remember how to halt the resonance that would destroy us both. And further, since I do not want you throwing shoes—” Professor Quirrell made another gesture, and just within the Greater Circle of Concealment, a slight shimmer appeared in the air, a globe-shaped distortion. “ Thiss barrier will explode if touched, by you or other material thing. The resonance might lash at me afterward, but you would also be dead. Now tell me in Parseltongue that you do not intend to cross this circle or take off your Cloak or do anything at all impulsive or stupid. Tell you me you will wait quietly here, under the Cloak, until this is over.” This Harry repeated back.

Then Professor Quirrell’s robes became black tinged with gold, such robes as Dumbledore might wear upon a formal occasion; and Professor Quirrell pointed his own wand at his head.

Professor Quirrell stayed motionless for a long time, still holding his wand to his head. His eyes were closed in concentration. And then Professor Quirrell said, “ Confundus. ”

At once the expression of the man standing there changed; he blinked a few times as though confused, lowering his wand.

A deep weariness spread over the face Professor Quirrell had worn; without any visible change his eyes seemed older, the few lines in his face calling attention to themselves.

His lips were set in a sad smile.

Without any hurry, the man quietly walked over to the Mirror, as though he had all the time in the world.

He crossed into the Mirror’s range of reflection without anything happening, and stared into the surface.