"Socrates," Cleon said, stopping the great man in the marketplace. "I have an inspirational idea for solving the underachievement of our young people."

"Oh yes?" Socrates replied wearily - he was used to Cleon's bossy brainwaves. "Tell me of your scheme."

"It has come to my attention," said Cleon, "that by the year 410 (counting backwards from here) a third of all adults and one-fifth of children will be clinically obtuse, with an average BMI ("brain-moron index") of over 35."

"Doesn't surprise me at all," said Socrates in an Eeyore sort of voice.

"But don't you see?" cried Cleon. "It's preventable! It's a lifestyle, not congenital, stupidity. Youngsters are running home from their pedagogues, and instead of doing homework, they're watching a box with pictures in it. Then they take hallucinogenic substances that rot their psyches." (All this is permitted and tolerated by their even dimmer parents, incidentally, Cleon glossed in a patronising way.) "Then, instead of all eating together on couches in a circle where they can have proper intelligent dialogue, as we are now ... "

(Humph, grunted Socrates)

"... members of households all eat separately, snatching food where they stand, so they never learn to debate or argue or think."

"Your analysis may be correct," conceded Socrates, but I still don't see what you can do about it. We live in a state where such choices are permitted. You may not like their values, you may think other values are better, but how can you force them to change without enslaving them?"

"We are going to send an army of slaves into all the houses where the BMI is over 40, and compel them to study, talk, and eat together. If necessary, and if the BMI is over 50, we will staple slates to the children, so they can't avoid reading them."

"But won't this be very expensive?" observed Socrates, getting straight to the point in a way that Cleon found very trying.

"Well, yes and no," said Cleon.

"Meaning?"

"To be exact, 63 million obols in the first year, and 40 million every year thereafter."

"Zeus, Hera and all the gods together strike a light!" said Socrates.

"But that's only half the story," Cleon added hurriedly. "It will actually save money in the long run."

"How d'you work that one out?" queried the philosopher.

"After, say, 10 years," Cleon said, "we'll be saving 20 million obols a year by not dishing out payments for stupid young men to sit at the gate doing nothing."

"That's not a saving," Socrates pointed out.

"So you see," Cleon went on without a pause, "within a generation the state will boast a lean, mean machine of fit young people."

"Let me just get this straight," Socrates summed up. "You're going to take even more money from those households that are bringing their children up sensibly and intelligently, and then - even though we haven't got enough money for expensive herbs for curing people of diseases they didn't choose, and can no longer care for the old and wise in our city - you wish to spend it on those households that prefer to bring their children up in a way that you don't approve of, in order to make them conform to something you do approve of?"

"Yes," said Cleon, beaming from ear to ear.

"And this is what we call freedom, and a modern democratic state?" pressed on Socrates, wanting to be absolutely sure he had understood properly.

"Yes," said Cleon.

"Where's that hemlock you offered me?" said Socrates.