An author from the Western Sahara was told by one of his guards, “You have come here to die. Forget the world outside! No one will ever read you, no one cares about you.” The prisoners used half of their bar of dark soap to write and stave off madness. One of them wrote a poem with hundreds of stanzas about Africa; the others learnt it by heart. They were seven tortured men in a cell with two square meters per person and hardly any light. The ability of some of them to use their imagination and create saved them. Imagination is the enemy of tyranny because it is an individual act that no one can control.

The Earth is not the inexhaustible resource we thought it was; it must be protected as something very precious. The same is true of the freedom of expression – it has no life of its own; it must be protected but also defined in a debate that is constantly being renewed. In a vulnerable world fraught with danger, the free flow of ideas plays a vital role. Th...