Fable
The gatekeeper no longer lets people through based on familiarity, but checks the city order item by item
North City began using automated carriages to deliver official documents. The carriages knew the roads quickly, could avoid congestion, and would deliver documents to different government offices by the color of their covers. For the first few days everyone marveled, until one carriage delivered the tax ledgers straight into a shop's back yard.
The cart driver argued that the back yard was closer to the tax collector and the road also connected. But the city order clearly stated: tax ledgers may enter only public offices and may not pass through private residences. Carts will find shortcuts, but they do not understand which roads, even if passable, should not be taken.
The city guard first sent people to follow the carts. With more people, speed slowed again, and no one watched urgent night deliveries. Later, craftsmen set up an iron judge beside the city gate: before each cart set out, the cover, destination, cargo type, and requester's wooden tag had to be inserted. The iron judge lowered the gate according to city orders, giving a green tag to those that could go, a yellow tag to those needing an officer's approval, and a red tag to those that absolutely could not go.
At first the city complained that there were too many red tags. The city guard then subdivided the city orders: ordinary notices could go through the narrow lanes, tax ledgers could only go along the official roads; disaster relief grain orders could pass at night, but required two seals; files sent to other provinces had to be registered first. Every time a cart was stopped, the iron judge carved the reason clearly on the plaque.
Later, when new carriages entered the city, they no longer relied on the driver's own judgment alone. They first learned the boundaries of the city's rules, then left a token trail for every passage and every refusal. The carriages still ran fast, but fast no longer meant arbitrary.
The city first pasted a no-go register on the carriage. But when the carriage encountered new alleys, temporary road closures and documents with different-colored covers, it still rushed along the shortcut. If the no-go register was scattered among drivers, gatekeepers and walls, the carriage could not grasp the same judgment when executing.
Later, the North City set up a rules room. Before each carriage departed, it had to submit its destination, document type, recipient identity, and route to the rules room for a ruling; if new situations arose along the way, it also had to turn back and ask whether it could proceed. The carriage was responsible for finding the road; the rules room was responsible for saying which roads were allowed and which actions must be stopped. Speed cannot replace boundaries.
The city guard finally said that truly effective rules cannot just hang on the wall for people to look at. They must stand before every clearance, able to judge, intercept, escalate, and leave a trace according to the same set of city ordinances.