The porter had just delivered the morning post.
Among the envelopes was a notice announcing the retirement of the college librarian.
Mr Blottisham sighed.
"I shall miss old Pembroke."
Professor Quillibrace looked up from his newspaper.
"Indeed."
"He seems as though he has always been here."
"No one has always been here."
"Well... it feels that way."
Miss Elowen Stray smiled.
"Institutions have long memories."
"They do," said Quillibrace, "though remarkably short biographies."
Blottisham looked puzzled.
"Biographies?"
"Of course."
"I thought biographies belonged to people."
"So they usually do."
Quillibrace folded his newspaper.
"But I have begun to suspect that scientific entities possess them as well."
Blottisham laughed.
"You mean electrons have childhoods?"
"Not quite."
"Black holes attend preparatory school?"
"I should hope not."
Miss Stray looked intrigued.
"What sort of biography?"
Quillibrace leaned back.
"The sort that begins with an introduction."
He counted quietly on his fingers.
"First..."
"...yes?"
"...someone proposes an entity."
"A hypothesis."
"Quite."
"Then?"
"It is questioned."
"Naturally."
"Modified."
"Often."
"Defended."
"Sometimes."
"Eventually accepted."
"Occasionally."
"And afterwards..."
"...yes?"
"...everyone forgets there was ever an argument."
Blottisham nodded.
"Like tenure."
Quillibrace smiled.
"A surprisingly apt analogy."
Miss Stray had risen and was examining the portraits that lined the Common Room walls.
"I've just noticed something."
"What is it?"
"None of these people arrived as portraits."
"No."
"They arrived as strangers."
"Indeed."
"They became colleagues."
"Yes."
"And only much later..."
"...they became part of the College."
Quillibrace regarded her approvingly.
"A concept's career may be remarkably similar."
Blottisham looked thoughtful.
"But surely some entities really exist."
"Perhaps."
"Electrons?"
"Perhaps."
"Black holes?"
"Perhaps."
"The ether?"
Quillibrace was silent.
"Oh."
"It is worth remembering," he said eventually, "that the ether once seemed every bit as respectable."
Blottisham shifted uneasily.
"But nobody believes in it now."
"No."
"Did the observations change?"
"No."
"The experiments?"
"No."
"What changed?"
Miss Stray answered softly.
"The role the ether played."
Quillibrace nodded.
"The observations remained."
"The mathematics improved."
"The explanations changed."
"And eventually..."
"...the ether retired."
Blottisham laughed.
"Without collecting a pension."
"I'm afraid so."
A comfortable silence followed.
Outside, the college gardener was removing an old wooden trellis that had long supported a climbing rose.
Miss Stray watched him carefully.
"The rose is still there."
"It is."
"But the trellis is coming down."
"Yes."
"Has the gardener removed the rose?"
"No."
"Only something that once helped it grow."
Quillibrace joined her at the window.
"I suspect many scientific entities begin life as trellises."
Blottisham looked surprised.
"Trellises?"
"They support understanding."
"They give shape."
"They make growth possible."
"But eventually..."
"...the structure may no longer be needed."
Blottisham frowned.
"So was the trellis false?"
"No."
"Was it a mistake?"
"No."
"It simply belonged to an earlier stage of the garden."
Miss Stray remained at the window.
"Perhaps that is why history can be so misleading."
"In what way?"
"We remember the flowers."
"Yes."
"But we forget the structures that once allowed them to grow."
The chapel bell rang across the quadrangle.
Blottisham picked up his hat.
"I've always imagined science as collecting more and more objects."
Quillibrace smiled.
"Perhaps."
"But now I wonder..."
"...yes?"
"...whether it is also quietly rewriting the cast list."
They stepped into the corridor together.
Behind them, the gardener carried the old trellis towards the tool shed.
The rose remained exactly where it had always been.
Only the architecture supporting it had changed.
For a moment, the three scholars watched in silence.
Then Miss Stray spoke almost to herself.
"It seems that even scientific things sometimes have histories before they have identities."
Quillibrace glanced at her with unmistakable satisfaction.
"And occasionally," he said, "they enjoy remarkably distinguished retirements."
The porter, overhearing only the last remark, assumed they were still discussing the librarian.
No one thought it necessary to correct him.