"I guess we'll see if we run across forty more of them or not."

"We haven't even met any fish-people yet." 

"Yeah. I wonder if I should just try to inventory the lot of them before I do anything major - I've already decided the summoning rollout needs to happen differently, the literacy rate just isn't high enough..."

"Is literacy rate important?"

"Enormously. Preprints are good - better, even - but widespread use of preprints requires widespread availability of printers, or demons. In my world the distribution was accomplished by giving everybody a good look at a daeva, and a book on summoning to read."

"You gave everyone a book?" 

"Not literally one per person, but I got pretty good coverage, yeah."

"That is a lot of books. What did you pay the demons?" 

"I had to shop around to find ones who wanted things I could get them, I was a high schooler, but some of them wanted things like to go to a mall and buy a coffee with money in real life."

"...Huh. Do you know why they wanted that?" 

"Novelty. Demons don't use currency."

"I guess that would be hard when everyone can just make whatever. --Is demonic counterfeiting a problem in 2159?"

"Nah, there's ways around it. It does take some doing, and it'll be harder on a 1928 tech base."

"What kinds of ways?" 

"So demons can make any physical thing, which means cash is right out. But for everyday transactions you can make someone scan their fingerprint or their retina - and you watch them do it so you're sure it's actually their fingerprint or retina, not a disembodied thumb or eyeball - or their voiceprint, sometimes, and match up that pattern with a centralized database that someone's gone to the trouble of positively identifying everyone in, and you can be sure they're actually trying to make a payment and their centralized bank can hand it over. That's not foolproof, but it's inconvenient for a demon to help someone route around, and there's more secure options yet for really big ticket stuff."

"Why is fingerprint or retina more secure than a signature?" 

"It's harder to have a machine tell that two signatures are by the same person and not make mistakes in either direction."

"If someone has to watch anyway why does there need to be a machine?" 

"Because the person watching doesn't know what your signature looks like, they're going to be a total stranger who works at a store."

"Oh, okay. It would be convenient if brains could be made to work more like computers, if they didn't lose anything important in the process." 

"It would! Not a lot of progress on that front, I'm sorry to disappoint."

"It probably wouldn't work for me anyway." 

"You'd need some separate R&D."

"And there's only one of me. Even Wilbur is put together differently from me." 

"I mean, if I were doing this I'd start testing stuff on mindless copies of you."