Researchers have conducted an investigation into the galaxy of occult societies since the advent of homo sapiens. They review all those companies whose purpose is the protection of ancient secrets of eternal wisdom (Templars, Rosicrucians, Freemasons, Kabbalist, satanic sects etc ...) through a hundred short chapters all highlight an esoteric quote (if not imbitable) except on a few occasions (see in particular those of Woody Allen and Karl Popper) that shed light on the true purpose of this novel. Because, in my opinion, it should not be mistaken: Umberto Eco is not a precursor of Dan Brown. It is perhaps even close to the anti-Dan Brown and, at the very least, it provides us the intimate key success of the novels kind Da Vinci Code.
Umberto Eco demonstrates that one can always find a mystery somewhere, with a little imagination and a very loose sense of cause and effect, we manage to find a link between these different societies, political ramification here, a philosophical extension there. Now their only link is the universal fantasy of the theory of global conspiracy, the need for humanity to explain the inexplicable by something that necessarily exceeds.
Esoteric novel enthusiasts for the pleasure of it and ésotériser us-cache-on-all-we-say-anything, go your way. You will not find in the Foucault pendulum reflection of your banal human condition.
This novel is sometimes painful to read, but it really worth the effort to go to the last page.