In my recent book Educating Against Extremism, I look at how and why extremists leave such movements. What triggers this is the realisation of alternative versions of "truth". Exit does not necessarily mean renouncing their religion, but embracing a far more nuanced and sceptical version. So if "Imams (are to be) asked into schools" (TES, May 30, above) - or indeed any religious leader - the question is whether they are prepared to discuss the more violent parts of their sacred texts, those that justify killing enemies and beating wives.
The way to protect against extremism is not for religious (or secular, or political) leaders simply to tell young people what they should do. This is authoritarianism, and fosters blind obedience. Instead, religious leaders and teachers need to acknowledge the doctrinal errors and atrocities committed by their religion - for example, the Inquisition, or supporting slavery, or hatred of non-believers.
The trick is to instil the ever-present possibility that our leaders have got it wrong. The other protection against extremism is, of course, satire - the ability to take a joke.
Schools need to teach the deconstruction of messages and slogans, and to explore the power of satire and cartoons to debunk grandiosity. The answer to extremism is not moderation - you can't do genocide in moderation - but a highly informed idealism. Extremism's major enemy is also a lightness of touch.
Professor Lynn Davies, Centre for International Education and Research, University of Birmingham.