How much does a person need to know before he can think critically? Ignorance, prejudice and wishful thinking can certainly imitate forms of critical thinking in a superficial way. But real critical thinking, which also entails an awareness of one’s own precarious conditions, is very rare. According to the national curriculum, Swedish pupils are supposed to learn critical thinking in school, as part of their personal development, and not least to grow up into full-fledged citizens in society. Critical thinking is considered fundamental to the development of well-functioning individuals in a democratic society.

But critical thinking is not an easy thing. It is a kind of opposition, an opposition that people must learn to exert or apply by using their knowledge constructively – or for that matter destructively, because it may actually involve confronting or demolishing others’ concepts and claims, or their own. It is easy to say what critical thinking is not,...