The way to deal with uncertainty is to analyze it into components. Most people who are reluctant to do something have about eight different reasons mixed together in their heads, and don’t know themselves which are biggest. Some will be justified and some bogus, but unless you know the relative proportion of each, you don’t know whether your overall uncertainty is mostly justified or mostly bogus.
Mapmakers deliberately put slight mistakes in their maps so they can tell when someone copies them. If another map has the same mistake, that’s very convincing evidence.
--Paul Graham, same essay
Same essay.