"Sophie's World" by Jostein Gaarder is a philosophical novel that takes readers on a journey through the history of Western philosophy. The story revolves around Sophie Amundsen, a young girl who starts receiving mysterious letters posing profound questions about existence and reality. Guided by her mentor, Alberto Knox, Sophie delves into the works of famous philosophers, from Socrates to Kant, exploring their ideas and their relevance to her own life. As Sophie unravels the secrets of the philosophical world, she discovers startling truths about herself and the nature of existence.