I’m convinced Dan Brown read Foucault’s Pendulum and thought “cool idea, I’ll write two dozen sequels where the Plan is real and nobody is punished for their epistemological sins. Also what the hell is a semiotician? My hero will be a Symbologist!”
I'm pretty much convinced that Brown cribbed his Da Vinci Code from a pulpy 80s book, this one. Annoyingly the authors didn't win their copyright case.
I remember reading it in the 90s and being very put off by the insanity and lack of logic. As it later turned out: The conspiracy theory of HBHG and DVC was in the end invented by a French document forger who in his own forgery seemed to be the last merovingian king/descendent of Christ:
