One of the main themes of The Boy Who Harnessed the Wind is of the opposition between magic and science. As a young boy, William has strong superstitions and believes in magic. But as he educates himself, he learns more about science. To him, magic is to be feared; science is to be revered. Magic represents the old way of thinking in Malawi, and science represents the nation’s future. After he builds the windmill and drought returns to Malawi, some of the villagers think that the windmill is causing it, by blowing the clouds away. This shows that while the people are eager for scientific progress, they have a harder time letting go of the past than William does.

William and his family, along with the rest of the Malawian people, are ruled by a corrupt government for much of the book. While this theme is not a dominant part of the narrative, it’s ever present. Trywell’s friends mysteriously disappear. After the Chief is beaten, he has to seek treatment discreetly, lest he incur further punishment. The government is willing to deny anything that would give it a bad image, even though such denial causes further damage.