Aristotle claimed that ‘all human beings want to know’. Yet we also want not to know. Centuries after the Enlightenment, mesmerised crowds still follow preposterous prophets; irrational rumours trigger fanatical acts; and magical thinking crowds out common sense and expertise. Where does this will to ignorance originate, and how does it shape our lives today? Acclaimed essayist and historian of ideas Mark Lilla offers an absorbing intellectual travelogue of the human will not to know. He ranges with brio from the Book of Genesis and Plato’s dialogues to Sufi parables and Sigmund Freud, revealing the paradoxes of hiding truth from ourselves. Lilla also exposes the illusions that this impulse can lead us to entertain: our belief in the ecstasies of prophet figures as a gateway to truth, the myth of children’s wise simplicity, and the yearning for vanished, allegedly purer civilisations.