People say things like: 'I used to be for openness and toleration of difference, but now I see where it's leading.' But where is it leading?

Almost every reason for toleration's apparent fall into disrepute concerns Islam. Even simple requests, such as that of Muslim schoolgirls to wear headscarves in class, are suddenly freighted with immense political significance and treated as issues that must be resolved at the highest level of government.

People - and their elected leaders as well - often have the feeling that such seemingly innocent proposals are in fact part of an ominous 'hidden agenda'.

That agenda is 'Islam', which many imagine to include all the terrible things that we read about in the press: the stoning of adulterous women under syariah law in northern Nigeria, the amputation of thieves' hands in Saudi Arabia, honour killings of women who refuse arranged marriages in Pakistan (or even northern English cities such as Bradford and Manchester), the willingness to justify suicide bombings.

The usual hype

IF YOU reply that the girls who want to wear headscarves to school are not living in Nigeria or Saudi Arabia, and almost certainly do not share the extreme Wahhabi views found in those countries, you will be met with a look of indulgent pity, a look of the type reserved for the terminally naive.

Or you will be told stories of how Saudi-trained imams are twisting the girls' arms, turning them into unwilling stalking horses for 'Islam'.

Indeed, it is virtually impossible nowadays to talk about headscarves as an issue in its own right. All the sociological evidence about the girls' motives, which are in fact very varied, is swept aside as irrelevant. All that matters is the threat posed by Islam.

This is a classic example of what I call 'block thinking', which seems to have made huge strides in Europe in recent years. John Bowen's recent book Why The French Don't Like Headscarves documents this shift.

Block thinking fuses a varied reality into one indissoluble unity, and in two ways. First, different manifestations of Islamic piety or culture are seen as alternative ways of expressing the same core meaning. Second, all Muslims are then seen as endorsing these core meanings.

The possibility that a girl wearing a headscarf might in fact be rebelling against her parents and their kind of Islam, and that others might be deeply pious while being utterly revolted by gender discrimination or violence, is lost from view.

Nightmare scenario

BLOCK thinking is an age- old phenomenon, and we all do it to some degree. But, while in another age we might have been indulgent about its consequences, today it has explosive potential, because people who think in this manner are prime recruits for seeing the world in terms of Samuel Huntington's theory of the 'clash of civilisations'.

What is worse, the way such people then act tends to edge us closer to Huntington's nightmare scenario. By treating all the varied segments of Islam as nothing more than parts of a unified threat to the West, they make it harder for Muslims to stand out and criticise their own block thinkers - like Osama bin Laden - who are building their own unified enemy, composed of 'Christians and Jews'.

Block thinkers on each side give aid and comfort to block thinkers on the other side, and with each exchange they pull us closer towards an abyss. So how can we stop this madness?

Block thought persists in part because its critics on each side are unknown to those on the other side. Indeed, how many times does a critic of European block thought meet this kind of response: 'But where are the Muslims who are criticising extremist Islam?'

Of course, one is not likely to meet them in the drawing rooms of Paris journalists or the wider European professional political class. But explaining that to block thinkers will never have the impact of a real connection to the multi-faceted discourse that is actually taking place on the other side.

The real question, then, is this: Where are the crossover figures who can provide that urgently needed connection?

The writer is professor emeritus of philosophy at McGill University, Montreal. His most recent book is The Secular Age.

Copyright: Project Syndicate/ Institute for Human Sciences