“Intelligence is traditionally viewed as the ability to think and learn. Yet in a turbulent world, there’s another set of cognitive skills that might matter more: the ability to rethink and unlearn.”

Grant takes for granted throughout the text that his readers are familiar with traditional conceptions of intelligence, and one of his major arguments is that we need to be open to and respect alternative ways of thinking about things. At the same time, he believes that otherwise intelligent people are missing this key skill. As a result, we are unable to progress as we should because this form of intelligence is undervalued.

“Yet there are also deeper forces behind our resistance to rethinking. Questioning ourselves makes the world more unpredictable.”

A key trend in the book is the idea that we avoid rethinking because we tie our thoughts, erroneously, to our identity. One reason we do this is because our thoughts inform, and help to stabilize, our worldview. In other words, Grant is arguing that we dislike rethinking because it destabilizes our carefully constructed identity.

“We’re swift to recognize when other people need to think again. […] Unfortunately, when it comes to our own knowledge and opinions, we often favor feeling right over being right.”

This connects to the larger theme of thinking like a scientist. For Grant, the other archetypes—preacher, prosecutor, and politician—are all informed by emotion. Instead, he thinks we should focus on searching for truth, and for him, this must be done through the scientific method.