Sophie's World by Jostein Gaardner

If there were awards for genre-crossing, this book would win. Part mystery story and part history of philosophy text, this unusual gem is a must-read. I'm not sure whether the philosophic community generally regards Darwin and Freud as members, but I'm in no position to quibble. And although the mystery didn't have the ending that I thought it should, the unraveling, re-raveling and ambiguity of reality certainly makes its point in a book about philosophy. The long passages covering the history of philosophy don't, surprisingly, weigh the book down. The author must have been an outstanding teacher.