Corner is silent.

He'll pull out some papers and start marking them. 

"If you think apologies are so great," Trembley tells Corner, "you could apologize for hitting me."

"You deserved it."

The boys glower at each other.

"Slytherins are better at this," he observes, "because they at least notice when what they're doing is not getting them what they want. Okay. Corner. You hate having a roommate who thinks you're less than he is. You - don't know any civilized ways to handle this problem? Don't see any reason to employ them instead of punching people? Care about emotional satisfaction more than solving the problem? Are imagining that if you just keep this up then, poof, Trembley'll stop existing and you won't have to learn mature problem-solving?"

"He doesn't have an intelligent rebuttal," says Trembley.

"You don't deserve an intelligent rebuttal, you can't just go around saying 'resolved: some people are worthless' and get treated like you said 'resolved: Transfiguration is more artistic than technical'."

"I bet he has a rebuttal more intelligent than the original argument, Trembley, you made a stupid argument. You've admitted you were wrong about it."

"He doesn't think I'm wrong he thinks I shouldn't even be thinking about it!" cries Trembley.

"Yep! But, you know, you were wrong, and I get the sense you do care about being right."

"I do and Phelps helped and you helped and he just wants license to punch me if I don't agree with him about everything without him even arguing!"

"Most people would've gone to the hospital wing, and then he'd get whipped and then it probably wouldn't happen again."

"My entire problem is that nobody should hit each other!"

"I know. It seems like it might not have occurred to Corner that this was an actual principle of yours even when you weren't the person affected."

"What am I supposed to do, thank him for not seeking medical attention?" says Corner.

"I'm going to tell Potter to stop setting detentions on that basis, it's not fair to leave a kid with the choice between getting medical attention or keeping their assailant safe. What you're supposed to do is cease assaulting your classmates who won't fight back."

"He can't just say whatever he wants and get away with it!"

"So, Trembley clearly showed up at Hogwarts believing lots of things that weren't true. I am sure with enough random violence you could scare him into not saying the things he believes, at least not while people who might disagree are around. Or, you know, he could say them, and you could ignore him, and people with more patience could explain why he's wrong, and then he'd stop believing those things. Which do you really care about more: what people say or what they think?"

"I don't care what he thinks, he's not worth that, I care if he gets anyone else to listen to him!"

"If I were an impressionable first-year and one of my classmates said something and another one punched him, I would not conclude that the punching one was philosophically in the right."

"If he shuts up it won't come to that."

"How's that working so far?"

"I've only had to punch him twice."

"I think it's working not at all. Until he knows how to jinx you he'll avoid talking in front of you, but Potter says Collins is now under the impression everyone agrees with him, and you can't be everywhere, and eventually you'll get in trouble no matter how hard he tries to protect you."

"Well, I can talk to Collins."