Fable
Told like a mapmaker who saw it with his own eyes
In Yuanxing Town there was a mapmaker who was a very good talker. When travelers asked him how to get to North Mountain, he could describe the rivers, woods, post stations and mountain passes, and it sounded as if he had walked the route many times himself. One day a merchant caravan asked him to draw the route to the silver mine. The mapmaker spread out paper and drew a stone bridge, three pine groves and an old well. He said, after crossing the bridge head west, and when you see the well turn right, and you will reach the silver mine. The caravan followed his directions and ended up in a swamp. There was no stone bridge there, and no old well.
The caravan came back and questioned him. The mapmaker was surprised and said he had not intentionally deceived anyone; he had merely inferred that the north was similar based on the appearance of several southern roads. Stone bridges are common, old wells are common, and this route sounded reasonable.
After hearing this, the old guide spread out the old map: the road you drew did not come from exact observation, it was only what you thought should exist. It looks like a real map, but it cannot lead anyone.
The mapmaker argued that his inferences were indeed useful in many cases. The old guide nodded: in casual chat, reasonable inference may be harmless; when a caravan sets out with goods, time, and risk, an error that sounds true is more dangerous than saying "I don't know."
Later, the town set three rules for the mapmaker. Roads walked with one's own eyes were drawn with solid lines, roads heard from others with dashed lines, and merely guessed roads could not be drawn as roads; key routes had to be checked against old maps and road signs; when uncertain, one had to say so clearly.
The mayor first told the mapmaker to speak more slowly and cautiously. But slowness could not make a nonexistent stone bridge appear, and caution could not find the traveler a road. What really needed to change was that beside every route there had to be labels for personally tested, heard, and inferred—the three could not be drawn with the same ink line.
Later, when travelers came again to ask the way, the mapmaker first laid out the old maps, the road steles, and the guides' accounts. Where there was no evidence, he would rather leave a blank than fill the page with handsome mountain lines. The caravans found that although the blanks looked ugly, they were more reliable than a confident false road.
The map lost its legendary flavor but saved more caravans. A reliable map does not rush to fill in every blank; it knows where the blanks still are.