Sophie’s World is an outline of Western philosophy that is beautifully set in a fictional story. It goes from pre-Socratic philosophy all the way to Sartre.
Jostein Gaarder does a very good job not just by writing a concise history of philosophy, but also by writing a very accessible book for as far as early teenagers, which in itself is worthy of high praise. His comparison between different philosophers throughout the book is truly remarkable and made the book very enjoyable. He demonstrates, for example, the contrast between Aristotle and Plato by comparing their views about reality and the mind in a way that no philosophy textbook of which I know does. While reading the book and recalling my philosophy classes back at school, I continuously wished that something like Sophie's World was taught there instead of the bleak philosophy textbooks of which I practically remember nothing.
However, some may feel that certain philosophers were ignored by the author. I believe this was due to his fictional story, which was fascinating with its twists, and the questions it raised. And, I don't think it's reasonable to expect a full account of Western philosophy being condensed in less than a 500-page book. I believe certain lesser-known philosophers had to be overlooked, not just to achieve brevity, but also to ensure full integration between the fiction and non-fiction of the book. Nevertheless, the book covers vast philosophical grounds and is highly informative.
Finally, I think the most important thing in Sophie's World was that it shed light on the significance of various discoveries and advancements of civilization in our reality, and the influence they exerted throughout the ages on our thoughts and philosophies. This, in my view, can be better demonstrate by an artist than by a philosopher, which is what Gaarder did in the book and that's exactly why I highly recommend it.