|The Disappearing Swan. Now you see it. Now you don't.|
Descartes' Demon has fog machines, fake signs,
and much much more to mess with your head.
The Disappearing Swans are mostly a rhetorical fiction -- an imaginary and socially constructed entity that is treated as real for the purposes of persuasion. They are often mentioned as reasons why we can never understand anything about any variety of Black Swan, especially those with "intelligent adversaries". I'm including Disappearing Swans in this series mostly for completeness and to make distinctions with other, more common Swans like Red Swans.