Anathem 

Description: Fraa Erasmus is a young avout living in the Concent of Saunt Edhar, a sanctuary for mathematicians, scientists, and philosophers, protected from the corrupting influences of the "Saecular" world by ancient stone, honored traditions, and complex rituals.
Over the centuries, cities, and governments have risen and fallen beyond the concent's walls. Three times during history's darkest epochs, bloody violence born of superstition and ignorance has invaded and devastated the cloistered mathic community. Yet always the avout have managed to adapt in the wake of catastrophe, becoming out of necessity more austere and less dependent on technology and material things. Erasmus, however, has no fear of the outside - the Extramuros - for the last of the terrible times was long, long ago.