Discuss identity. Sophie and Hilde are both similar young girls with the same birthday. At the end, when Sophie sees Hilde, Sophie notes that Hilde is prettier than she. Likewise Alberto, the philosophy teacher and Major Knag have similarities. What differences, if any, do you see in these pairs of people. What effect does this have on the book's dealing with two parallel universes?

Compare Alberto and Major Knag. Is Major Knag as good a philosophy teacher in the last chapter as Alberto has been to Sophie? Does Alberto seem like a direct projection of Major Knag into the story, or is Alberto an ideal philosophy teacher created in the mind of Major Knag?

Sophie feels she is learning much more in her private philosophy course than she does at school. What is distinct about the philosophy course from ordinary school learning? Could the...