As promised, this book does give an introductory overview of philosophical thought in an unusual way. The reader enters into Sophie's quest to unravel the mystery of the notes and postcards and later participates in her philosophy lessons with Alberto. Perhaps most interesting, as it delves into the foundations of philosophical thought, is the doubt cast on Sophie's existence as other than a figment of the imagination of Hilde's father. This is a clever interrogation of multiple realities.

I found Sophie herself rather irritating, particularly her observations during Alberto's expositions, but realize that these probably help to clarify the concepts. One loose end was her father, absent at sea. Alberto obviously takes on the role of father-figure but never quite steps into these shoes and the parallel figure of Hilde's father suggests Sophie's yearning for a more regular family situation.