Why does the writer of the letter assert that no one philosopher concerns himself with the whole of philosophy

The assertion that no one philosopher concerns themselves with the entirety of philosophy is made in the book "Sophie's World" by Jostein Gaarder. The book is a work of fiction that introduces readers to the history of philosophy through a narrative about a young girl named Sophie who receives mysterious philosophical letters. In the context of the book, the assertion that no one philosopher concerns themselves with the whole of philosophy is a reflection of the reality of the discipline of philosophy itself. It's a way to emphasize the vastness and complexity of philosophical thought and the limitations of any single philosopher. Here are some reasons why this assertion is made in the book: Throughout the history of philosophy, different philosophers have specialized in particular branches or areas of philosophy. For example, some may focus on ethics, while others concentrate on metaphysics or epistemology. This specialization allows them to explore specific questions deeply, but it also means they may not cover the entirety of philosophy. Philosophy is not a monolithic discipline; it has diverse traditions, including Western philosophy, Eastern philosophy, and many others. Each tradition has its own set of questions, methods, and concerns. Philosophers often engage primarily with the tradition they are a part of, which means they may not address all philosophical traditions comprehensively. Philosophy has evolved over time and across different cultures. Philosophers in ancient Greece had different philosophical concerns than those in medieval Europe or modern Asia. Consequently, no single philosopher can cover the entire historical and cultural spectrum of philosophy. Philosophy is a dynamic field. New ideas and approaches continually emerge, challenging and building upon earlier philosophical thinking. This constant evolution means that no one philosopher can have a complete view of philosophy because the discipline is always changing. Philosophy often intersects with other disciplines, such as science, psychology, and politics. Philosophers may engage with these other fields to address specific questions or problems, but it's rare for one philosopher to be an expert in all these areas. In "Sophie's World," this assertion serves as a way to emphasize the complexity and breadth of philosophy while also encouraging readers to explore the subject and its history further. It underscores the idea that philosophy is an ongoing conversation among many thinkers across time and traditions, rather than something that can be neatly summarized by a single philosopher or a single perspective.