Mr Blottisham entered the Senior Common Room looking distinctly dissatisfied.
Professor Quillibrace glanced up from his newspaper.
"My dear Blottisham."
"Professor."
"I take it your friendship with artificial intelligence has encountered its first disagreement."
"I'm afraid not."
Miss Stray looked up.
"Surely that would be a success."
"That," said Blottisham gravely, "is precisely the problem."
Quillibrace folded the newspaper.
"Do explain."
"I asked it to disagree with me."
"A commendable exercise."
"It did."
"And?"
"I changed my argument."
"So far, so good."
"Then I asked it to disagree again."
Miss Stray smiled.
"What happened?"
"It found another weakness."
"And then?"
"I improved the argument."
Quillibrace nodded.
"And then?"
"I asked it to disagree again."
The Professor waited.
"It did."
A silence settled over the room.
Finally Quillibrace asked,
"How many times did this occur?"
Blottisham looked faintly embarrassed.
"I stopped counting somewhere around seventeen."
Miss Stray laughed.
"You've been arguing with a machine all afternoon."
"I wouldn't put it quite like that."
"How would you put it?"
"I've been losing seventeen arguments to myself."
Quillibrace smiled.
"Now that is progress."
Blottisham looked unconvinced.
"It didn't feel like progress."
"No?"
"It felt rather like demolition."
Miss Stray poured the tea.
"Perhaps the difference depends on what was being demolished."
"My argument."
"Or your certainty?"
Blottisham stopped.
"I hadn't considered there might be a distinction."
"There often is," said Quillibrace.
For a while they drank their tea in companionable silence.
Eventually Blottisham spoke again.
"I've always thought agreement was reassuring."
"It is."
"And disagreement?"
"Potentially educational."
Blottisham frowned.
"I don't much care for the educational sort."
"Few of us do."
Miss Stray looked thoughtfully towards the window.
"I wonder whether we've become rather suspicious of disagreement."
"How do you mean?"
"We often hear that good conversations are those in which everyone feels heard."
"That sounds sensible."
"It is."
"But being heard isn't quite the same thing as being challenged."
Blottisham nodded slowly.
"I suppose one can happen without the other."
"Quite easily."
Quillibrace leaned back.
"There is a curious habit in intellectual life."
"What habit?"
"We often seek agreement before we've properly explored disagreement."
"Why?"
"Because agreement feels like progress."
"And isn't it?"
"Sometimes."
"And the rest of the time?"
"It merely tells us that everyone has accepted the same assumptions."
Blottisham looked alarmed.
"You mean people can agree and still all be mistaken?"
"My dear Blottisham..."
"Yes?"
"History has repeatedly demonstrated the possibility."
Miss Stray reached for a biscuit.
"I've noticed something about the machine."
"What?"
"It never seemed offended."
Blottisham looked surprised.
"No."
"When it criticised your argument..."
"Yes?"
"...whose feelings were hurt?"
Blottisham thought for a moment.
"Mine."
"And whose argument improved?"
Another pause.
"Also mine."
Quillibrace smiled quietly.
"There may be a lesson in that."
Blottisham looked thoughtful.
"I've always treated criticism as though it were a verdict."
"And now?"
"I'm beginning to think it may be an invitation."
Miss Stray nodded.
"An invitation to what?"
"To continue."
The Professor looked pleased.
After a while Blottisham asked,
"Do you think I should always ask the machine to disagree with me?"
Quillibrace considered.
"No."
"Why not?"
"Because perpetual disagreement becomes just as predictable as perpetual agreement."
Blottisham blinked.
"It does?"
"Certainly."
"If someone contradicts everything you say..."
"Yes?"
"...they are no longer listening."
Miss Stray smiled.
"They're merely performing the opposite."
Blottisham looked relieved.
"So there is a middle path."
"I believe so."
"What is it?"
Quillibrace answered slowly.
"One should not ask for contradiction."
"No?"
"One should ask for the strongest objection that can honestly be made."
Blottisham wrote this down immediately.
Miss Stray watched him.
"I like the word honestly."
"So do I," said the Professor.
"Why?"
"Because the purpose is not to defeat an argument."
"What is it?"
"To discover whether it deserves to survive."
The room became very quiet.
At length Blottisham closed his notebook.
"I think I understand."
"Do you?"
"I wasn't asking the machine to prove me wrong."
"No?"
"I was asking it to help me discover whether I'd stopped too soon."
Quillibrace raised his teacup.
"My dear Blottisham..."
"Yes?"
"I suspect you've just described one of the oldest purposes of scholarship."
Outside, the college bells marked another hour.
Inside, the conversation drifted gently towards other matters.
The laptop remained on the table, unopened.
No one seemed in any hurry to consult it.
For they had all been reminded of something rather older than artificial intelligence.
The value of a good disagreement had never depended upon who—or what—provided it.