No.12 Referenced from ~ Part1 - Chapter 2 - Parable

Parable of the "Meter Prototype"

A story from a planet. There was only one "Meter Prototype," which was inconvenient, so copies were distributed to each country. In the meantime, the "Meter Prototype" was lost. People got together and decided to redefine "1 meter." Copies of the meter prototype from each country were collected and compared, but naturally, there was a very small variation in the length of each stick.

So they thought. If they compared them exactly and took the average, they should be able to get the correct "1 meter". It seemed like a good idea.

Then, however, a "Meter Stick" was brought in. People tried to add it to the line of copies of the meter prototype, but the stick made a surprising claim. It said, "I am the lost Meter Prototype."

They had to think carefully about what to do with the stick. If that stick's claim is correct, adding it and averaging will give us a more accurate value. But it was soon realized that this was a foolish idea. This is because, if the stick's claim is correct, then the length of the stick itself should be considered as "one meter" and all other sticks should be discarded.

But what if the stick is telling a lie or is just mistaken itself? Obviously, that stick should not be added to the line of meter prototype copies.This is because it is either a fake or a counterfeit of unknown origin, and doing so would ruin the metric approximation.

In the end, they came to the conclusion that "the stick claiming to be the meter prototype should be treated differently."