Gödel

Godel's incompleteness theorems are fundamental to understanding the limits of scientific and mathematical knowledge and the power of self-reference.

Gödel, Escher, Bach should be considered required reading for a full understanding of metaculture.

Here's a basic explanation of Gödel's incompleteness theorem if such a thing exists.

A free online course from MIT is available to help get the most out of this seminal work.

Technically this is based on another book by Hofstadter but it does a good job explaining a lot of the concepts of recursion and consciousness that are in GEB.