“Can I borrow the towel?”
“It's yours anyway, Mr. Legibus.”
“Is it?”
“I said, you left it here last time. Remember? When you had that idea for the lighthouse?”
“Fine. Fine,” said Legibus, wrapping the towel around himself. He drew a few more lines on the wall. “Fine. Okay. I'll send someone down later to collect the wall.”
He turned and appeared to see the Omnians for the first time. He peered forward and then shrugged.
“Hmm,” he said, and wandered away.
Brutha tugged at the cloak of one of the Ephebian soldiers.
“Excuse me, but why did we stop?” he said.
“Philosophers have right of way,” said the soldier.
“What's a philosopher?” said Brutha.
“Someone who's bright enough to find a job with no heavy lifting,” said a voice in his head.
“An infidel seeking the just fate he shall surely receive,' said Vorbis. ”An inventor of fallacies. This cursed city attracts them like a dung heap attracts flies."
“Actually, it's the climate,” said the voice of the tortoise. “Think about it. If you're inclined to leap out of your bath and run down the street every time you think you've got a bright idea, you don't want to do it somewhere cold. If you do do it somewhere cold, you die out. That's natural selection, that is. Ephebe's known for its philosophers. It's better than street theater.”
“What, a lot of old men running around the streets with no clothes on?” said Brutha, under his breath, as they were marched onward.
“More or less. If you spend your whole time thinking about the universe, you tend to forget the less important bits of it. Like your pants. And ninety-nine out of a hundred ideas they come up with are totally useless.”
“Why doesn't anyone lock them away safely, then? They don't sound much use to me,” said Brutha.
“Because the hundredth idea,” said Om, “is generally a humdinger.”
“What?”
“Look up at the highest tower on the rock.”
Brutha looked up. At the top of the tower, secured by metal bands, was a big disc that glittered in the morning light.
“What is it?” he whispered.
“The reason why Omnia hasn't got much of a fleet any more,” said Om. “That's why it's always worth having a few philosophers around the place. One minute it's all Is Truth Beauty and Is Beauty Truth, and Does a Falling Tree in the Forest Make a Sound if There's No one There to Hear It, and then just when you think they're going to start dribbling one of 'em says, Incidentally, putting a thirty-foot parabolic reflector on a high place to shoot the rays of the sun at an enemy's ships would be a very interesting demonstration of optical principles,” he added. “Always coming up with amazing new ideas, the philosophers. The one before that was some intricate device that demonstrated the principles of leverage by incidentally hurling balls of burning sulphur two miles. Then before that, I think, there was some kind of an underwater thing that shot sharpened logs into the bottom of ships.”
Brutha stared at the disc again. He hadn't understood more than one-third of the words in the last statement.
“Well,” he said, “does it?”
“Does what?”
“Make a sound. If it falls down when no one's there to hear it.”
“Who cares?”
The party had reached a gateway in the wall that ran around the top of the rock in much the same way that a headband encircles a head. The Ephebian captain stopped, and turned.
“The . . . visitors . . . must be blindfolded,” he said.