A strange loop arises when, by traversing the levels of some hierarchy, you unexpectedly find yourself back where you began. Hofstadter discovered this pattern woven through Gödel's incompleteness theorems, Escher's impossible staircases, and Bach's endlessly rising canons. The loop is not a defect in the system — it is the system becoming aware of itself.

“This sentence is the last sentence of this page, except that it is now superseded by this one.”