Alberto Knox represents the ideal teacher in Sophie's World. He is intelligent and demanding, yet concerned with the understanding of his pupil. Furthermore, what he teaches has great personal relevance and he tries to inspire this same feeling in Sophie. Of course, Alberto and Sophie are actually able to answer part of the question regarding their existence and so philosophy has a more direct import for them. However, Albert uses Alberto to teach Hilde and he is inspiring to her as well. Alberto also makes Sophie come to many of her own conclusions, rather than thinking for her. Such an interactive method of learning seems critical for philosophy, something that we need to be able to do on our own and all the time.
Hilde reads Sophie's World the way we all should. She thinks about everything that Sophie is learning and applies it to her own existence. Hilde does not simply agree with Sophie or Alberto but takes their thoughts and uses them to come up with her own insights. She thinks philosophically and critically. Furthermore, Hilde questions the text itself. She wonders why her father does some of the things that he does. It is important not to be indoctrinated. Descartes decided all of the learning passed down from the Middle Ages was worthless. We must likewise decide what to take from a book and what to disagree with. Gaarder wants us to question above all else and Hilde does this.
Sophie takes Alberto's lessons to heart. The difference between her lessons with Alberto and her attitude towards school is marked and telling. School is an attempt to teach us things that will be valuable to us in life, but it is not always successful. There are some things in school that will not be very helpful to us. Sophie is eager to learn but she also can tell what resonates with her and what does not. She understands the relevance of philosophy and after her time with Alberto she is clearly a philosopher of her own accord. But our lifestyles and the societies we live in often take us away from philosophical reasoning, even if as children we are very close to it. Therefore we need to be good learners and students so that we can seize the opportunity to become philosophers should it come our way.