I wish all my textbooks were this entertaining! I had to read this book for my Philosophy class, and it is really great. It is an actual novel, there's a story, but it also includes a superb overview of the history of philosophy from Thales all the way up to modern New Age philosophies. It's about a girl named Sophie who starts getting strange letters in the mail from a mysterious major who wants to teach her about philosophy. They begin a sort of correspondence course through the mail. Sophie recieves pages on various philosophers which we, too, read. However, Sophie starts finding letters adressed to a girl named Hilde Knag, all of which mention sophie and are postmarked June 15, Hide and Sophie's birthdays. This is only the tip of the iceberg, as things start getting stranger and stranger in Sophie's World. The novel ties the story in with philosophy, particularly Berkeley's, very well. I really loved this book and it actually made me rethink lots of things that I had previously taken for granted.