“On some shelf in some hexagon [within the Library of Babel], it was argued, there must exist a book that is the cipher and perfect compendium of all other books *** How was one to locate the idolized secret hexagon that sheltered [this perfect book]? Someone proposed searching by regression. To locate book A, first consult book B, which tells where book A can be found; to locate book B, first consult book C, and so on, to infinity … It is in ventures such as these that I have squandered and spent my years.” (English translation by Andrew Hurley; emphasis added by us; image below courtesy of Kristofer Porter.)
“En algún anaquel de algún hexágono (razonaron los hombres) debe existir un libro que sea la cifra y el compendio perfecto de todos los demás [libros en la Biblioteca de Babel] *** ¿Cómo localizer el venerado hexágono secreto que lo hospedaba? Alguien propuso un método regresivo: Para localizar el libro A, consultar previamente un libro B que indique el sitio de A; para localizar el libro B, consultar previamente un libro C, y así hasta lo infinito … En aventuras de ésas, he prodigado y consumido mis años.”
Jorge Luis Borges, “La biblioteca de Babel” (1941).
prior probability 
The search for truth is a kind of Borgesian regress
Also, now that I think of it, it could also be argued that the doctrine of stare decisis in law is also a kind of Borgesian regress!