I have read this HUGE book more than once in order to understand it. Today I revisit it, and intend to read it once again, but to look at it from yet another point of view.

Umberto Eco - one of my favorite writers/thinkers. HIs book "Foucault's Pendulum" - one of the most amazing books I have read. Philosophical, arcane, searching, intriguing, and somewhat unsettling. Deeply probing knowledge and conspiracy in a web of symbolism and metaphors.