After a period in which it seemed to be a declining force religion is once again a deciding factor in world affairs. The revival of the Rushdie affair, the Bush administration’s opposition to stem cell research and the militant clericalism of the current Polish government are only a few examples of a trend that shows no sign of reversing in the foreseeable future. Far from fading away, or retreating into private life, religion is once again at the heart of politics.

In many countries, politicians and opinion-formers seem baffled by this development. A belief in an ongoing process of secularisation has been part of western intellectual life for generations. From the Marquis de Condorcet to Karl Marx and up to the present day, Enlightenment thinkers have argued that religion is a by-product of backwardness. In this view, as knowledge, wealth, education and democracy spread, the power of religion is bound to dwindle. Our view of the world will be increasingly shaped by science, and rather than looking for solace in the afterlife we will hope for continuing improvement in the human condition. At some point, human beings will no longer need religion at all.