“A sieve,” said Brinnaria, “is a sieve.”

“Not at all,” Commodus objected. “There are sieves and sieves.”

“Well, of course,” Brinnaria reflected, “I do not mean a broken, worn-out or imperfect sieve, nor one incompetently made.”

“Just so,” the Emperor amplified. “You propose to carry water in a sieve with a circular rim, without any hole, crevice or crack in it and with a web stretched taut on the rim, evenly woven and of the finest mesh.”

“That expresses my unformed idea,” said Brinnaria.

“Did you mean a linen sieve,” the Emperor asked, “or a horse-hair sieve, or a metal sieve?”

“That,” said Brinnaria, “can make no difference, if it fulfills the conditions you have just specified. I leave the choice of material to you.”

“That is the correct attitude for you,” said Commodus, “and does you credit.

“And now I think we four will settle the other details without you. Do you agree to that?”

“No!” Brinnaria objected. “I think I should be a party to the settling of several other details.”