Jane loses a tooth. She puts it under a pillow. She stares at the pillow. Martin looks doubly annoyed.
“First, ” Martin says, “tooth fairies have no purpose for existence. Second, they don’t come out when you’re watching.”
“I will impress her with tireless vigilance!”
“It’s still a waste of time,” Martin says.
“I’ve dedicated my whole life to growing teeth,” Jane says. “I eat food, and then I use metabolic energy to create them! I also create muscle, skin, brain tissue, and blood, but the teeth are the most immediately liquid wealth.”
“Things only have value if they’re nailed to a standard of exchange,” Jane says. “Like that guy. The one who got nailed to the standard of exchange.”
“I’m not sure whether you mean Midas or Jesus,” Martin says.
Jane waves a hand airily. “Or currency.”
“So that’s why it’s important,” Jane says. “The tooth fairy comes to all the kids who aren’t sure if they’re really valuable and says, ‘Look! I can exchange your enamel for cold hard cash!’ That sets a baseline. The kids can be worth more than that, but never less.”
“What about the people she doesn’t visit?”
“They can still take heart in the abstract knowledge that their body is backed by silver,” Jane says. “They just lack the facilities to make a proper currency exchange!”