"Sophie's World" is a novel by Jostein Gaarder that introduces readers to the history of philosophy through the eyes of a young girl named Sophie Amundsen. As Sophie receives mysterious letters that pose philosophical questions, she embarks on a journey to explore the ideas of famous philosophers, from Socrates to Kant. The book combines a coming-of-age story with an educational narrative, making complex philosophical concepts accessible to readers of all ages. Through her discoveries, Sophie learns about existence, knowledge, and the nature of reality, ultimately leading to profound questions about her own life and the world around her.