Harry Potter and the Methods of Rationality

'No,' said Hermione Granger.

Her voice was calm, and even though it wasn't loud, everyone heard it in the silence.

'Then I must deduct one point from you,' said Professor Quirrell. 'This is a test, and you have failed it.'

That reached her. Harry could see it. But she kept her shoulders straight.

Professor Quirrell's voice was sympathetic and seemed to fill the whole room. 'Knowing things isn't always enough, Miss Granger. If you cannot give and receive violence on the order of stubbing your toe, then you cannot defend yourself and you will not pass Defence. Please rejoin your classmates.'

Hermione walked back towards the Ravenclaw cluster. Her face looked peaceful and Harry, for some odd reason, wanted to start clapping. Even though Professor Quirrell had been right.

'So,' Professor Quirrell said. 'It becomes clear that Hermione Granger is not the most dangerous student in the classroom. Who do you think might actually be the most dangerous person here? - besides me, of course.'

Without even thinking, Harry turned to look at the Slytherin contingent.

'Draco, of the Noble and Most Ancient House of Malfoy,' said Professor Quirrell. 'It seems that many of your fellow pupils are looking in your direction. Come forth, if you would.'

Draco did so, walking with a certain pride in his bearing. He stepped onto the dais and looked up at Professor Quirrell with a smile.

'Mr. Malfoy,' Professor Quirrell said. 'Fire.'

Harry would have tried to stop it if there'd been time but in one smooth motion Draco spun on the Ravenclaw contingent and raised his wand and said 'Mahasu!' like it was all one syllable and Hermione was saying 'Ow!' and that was that.

'Well struck,' said Professor Quirrell. 'Two Quirrell points to you. But tell me, why did you target Miss Granger?'

There was a pause.

Finally Draco said, 'Because she stood out the most.'

Professor Quirrell's lips turned up in a thin smile. 'And that is the true reason why Draco Malfoy is dangerous. Had he selected any other, that child would more likely resent being singled out, and Mr. Malfoy would more probably make an enemy. And while Mr. Malfoy might have given some other justification for selecting her, that would have served him no purpose save to alienate some of you, while others are already cheering him whether he says anything or not. Which is to say that Mr. Malfoy is dangerous because he knows who to strike and who not to strike, how to make allies and avoid making enemies. Two more Quirrell points to you, Mr. Malfoy. And as you have demonstrated an exemplary virtue of Slytherin, I think that Salazar's House has earned a point as well. You may rejoin your friends.'

Draco bowed slightly and walked back to the Slytherin contingent. Some clapping started from the green- trimmed robes, but Professor Quirrell made a cutting gesture and silence fell again.

'It might seem that our game is done,' said Professor Quirrell. 'And yet there is a single student in this classroom who is more dangerous than the scion of Malfoy.'

And now for some reason there seemed to be an awful lot of people looking at...

'Harry Potter. Come forth.'

This did not bode well.

Harry reluctantly walked towards where Professor Quirrell stood on his raised dais, still leaning slightly against his teacher's desk.

The nervousness of being put into the spotlight seemed to be sharpening Harry's wits as he approached the dais, and his mind was ruffling through possibilities for what Professor Quirrell might think could demonstrate Harry's dangerousness. Would he be asked to cast a spell? To defeat a Dark Lord?

Demonstrate his supposed immunity to the Killing Curse? Surely Professor Quirrell was too smart for that...

Harry stopped well short of the dais, and Professor Quirrell didn't ask him to come any closer.

'The irony is,' said Professor Quirrell, 'you all looked at the right person for entirely the wrong reasons. You are thinking,' Professor Quirrell's lips twisted, 'that Harry Potter has defeated the Dark Lord, and so must be very dangerous. Bah. He was one year old. Whatever quirk of fate killed the Dark Lord likely had little to do with Mr. Potter's abilities as a fighter. But after I heard rumors of one Ravenclaw facing down five older Slytherins, I interviewed several eyewitnesses and came to the conclusion that Harry Potter would be my most dangerous student.'

A jolt of adrenaline poured into Harry's system, making him stand up straighter. He didn't know what conclusion Professor Quirrell had come to, but that couldn't be good.

'Ah, Professor Quirrell -' Harry started to say.

Professor Quirrell looked amused. 'You're thinking that I've come up with a wrong answer, aren't you, Mr. Potter? You will learn to expect better of me.' Professor Quirrell straightened from where he had leaned on the desk. 'Mr. Potter, all things have their accustomed uses. Give me ten unaccustomed uses of objects in this room for combat!'

For a moment Harry was rendered speechless by the sheer, raw shock of having been understood.

And then the ideas started to pour out.

'There are desks which are heavy enough to be fatal if dropped from a great height. There are chairs with metal legs that could impale someone if driven hard enough. The air in this classroom would be deadly by its absence, since people die in vacuum, and it can serve as a carrier for poison gases.'

Harry had to stop briefly for breath, and into that pause Professor Quirrell said: