Fable
The city's public notices and the machine's manual
Many shops opened in Riverbend City—mills, pharmacies, and money houses all bought machines that turn automatically. The city hall worried about trouble, so it posted a notice at the city gate: which industries may use machines, which tasks must have a person watching, and which ledgers must not be fed to machines. Shopkeepers entering the city each day first read this large notice.
After the notice was posted, the mill owner was delighted. Seeing that grain processing was listed as permitted, he immediately moved the new machine into the back yard and even tore down half of the old stone mill. But hanging beside the machine was a thin manual that read: only dry grain may be milled, not wet wheat; it must not be left unattended at night; if stones are encountered, the machine must be stopped.
The shopkeeper thought city hall had already nodded, that the manual was just fine print, so he had the workers run the machine at night too. In the middle of the night damp wheat jammed the gears, the whole belt snapped, and the warehouse was covered in flour. The next day he went to city hall to argue, and the official asked only one question: did you use that machine according to its own rules?
The pharmacy also encountered the opposite problem. A city hall notice said that herbal sorting could use machines, but prescription decisions must be handled by the attending physician. Yet the pharmacy's sorting machine manual was very strict: anything with similar drug names, similar colors, or unknown origin must be placed in the manual review basket. The assistant, finding it slow, emptied the review basket and nearly mixed up two medicines.
Only then did the shopkeepers realize that the city gate announcement governs the boundaries of the whole city: which industries can use machines, who is responsible, whom to seek when an accident occurs. The machine manual governs the actions of one machine: what it can touch, where it can stop, and whether to call a person when it encounters a difficulty. The announcement gives entry permission; the manual gives the measure of action. Neither rule alone is enough.
Later the city hall held the briefing again. Officials hung the announcement on the wall and placed the manuals for each machine beside it. Shopkeepers first had to confirm that their industry was permitted, then confirm whether the machine in hand could perform that specific task. The city hall did not start the machines, and the manuals could not approve a business for the city either.
From then on, Riverbend City had far fewer disputes. The grand proclamation decided whether a category of things could enter the city, and the manual decided how a particular machine should operate in the shop. The shopkeepers finally stopped using a city gate proclamation to replace the few pages of detailed rules beside each machine.