A Norwegian bestseller, FTP, what is this novel by Jostein Gaarder?
An unusual blend of textbook and novel, it was written by a former high school teacher who wanted to write an introduction to philosophy within the framework of a mystery story.  The title character receives strange mail addressed to someone called "Hilde," and her attempts to discover their source lead her to a course in western philosophy. A Norwegian bestseller, FTP, what is this novel by Jostein Gaarder?
An unusual blend of textbook and novel, it was written by a former high school teacher who wanted to write an introduction to philosophy within the framework of a mystery story.  
Sophie's World (or _Sofies verden_)