Foucault's Pendulum (original title: Il pendolo di Foucault) is a novel by Italian novelist and philosopher Umberto Eco. It was first published in 1988; the translation into English by William Weaver appeared a year later. It is full of obscure esoteric references to such elements as the Kabbalah, alchemy and conspiracy theory. The novel is an encyclopedic work, with critic and novelist Anthony Burgess suggesting that it needed an index (See: List of Esoteric Subjects in Foucault's Pendulum). The name of the book derives from an actual pendulum designed by the French physicist Léon Foucault to demonstrate the rotation of the earth. The book deals with the nature of power, and it has been theorized that the title might also refer to French philosopher Michel Foucault and his studies on power and knowledge, but he is never actually mentioned in the text.
Foucault's Pendulum is divided into ten segments represented by the ten Sefiroth. Told in the form of a kind of satirical intellectual game, three friends create a fictitious plan (the "Plan") that stretches throughout history and combines elements from various conspiracy theories. They feed the plan into a computer that in turn helps them formulate a new conspiracy theory, which is then believed to be true by adherents of the previous conspiracies, leading to disastrous consequences.
