MAAJID NAWAZ (pictured) and his favourite interlocutor Sam Harris are at first sight an unlikely pair, but they are doing their best to find common ground and get their act together. Mr Nawaz is a British-born Muslim who went through a radical fundamentalist phase and was imprisoned in Egypt; two years after his release in 2006 he co-founded Quilliam, a London-based research institution which describes itself as an anti-extremism think-tank. Mr Harris is a well-known atheist public intellectual in the United States. A short but intensive dialogue between them is being published this week as a slim volume by Harvard University Press, and we can expect to hear a lot more from them, on talk-shows and in the more cerebral parts of the print media, over the coming months. Their conversation sprang out of an initially abrasive encounter after a debate in 2010, when Mr Harris put it to Mr Nawaz that liberal-minded Muslims were engaged in a near-impossible task: proving that their faith was really a religion of peace when the tenets and scriptures of the faith suggested otherwise.

That is still, broadly speaking, what Mr Harris thinks. He sees the elaboration of a peaceful and tolerant understanding of Islam as a praiseworthy enterprise, and one that only Muslims can undertake, but he is politely sceptical of their chances of succeeding. Mr Nawaz's reply is a measured one. He says that Islam is neither a religion of peace nor a religion of war. It is simply a religion, and one that has been subject to many different interpretations over the centuries, and is still refracted in lots of different ways.

At times, Mr Nawaz is disarmingly frank. He acknowledges that reform-minded characters like himself, who want to combine Islam with secular governance and western ideas about equality, are in a small minority in the Islamic world. But he insists that Islamists (in the sense of people who believe in using state power to enforce a particular version of Islam) are also in a minority, albeit quite a large one. The biggest category of people in the Islamic heartland, as he describes it, are "conservative Muslims" who "generally don't want the state to impose their religion, because they want to retain the right to their own understanding of what this religious conservatism means." Moreover these "conservative Muslims can be very useful as allies against Islamism and jihadism, but they may oppose you on gender rights and equality...".

That is a remarkable thing for Mr Nawaz to be saying, because it runs counter to a lot of the material that his think-tank produces. Quilliam has been one of the propagators of a new conventional thinking about how Britain and other western states should deal with the challenge of militant Islam. According to this line of thought, which has gained a lot of influence in high places, socially conservative Islam is a gateway to violent Islam, and the two things must be fought with equal determination, even if that means hugely increasing the number of people you are confronting, and forfeiting a useful ally against jihadism.

It's worth teasing out the implications of what Mr Nawaz is saying. Over-simplifying only a little, let us agree that of the world's 1.6 billion Muslims, some 10% are open, as of now, to his proposal for a form of Islam that fits comfortably with secularism, human rights and equality. Let's also say that 25% lean towards one or other version of Islamism, the idea of state-imposed religion, and that within that category 10% of the total are supporters of violent jihadism. And let's suppose that the remaining 65% are conservative believers, neither liberal nor Islamist.

Going by what Mr Nawaz says in this book, then it might in certain circumstances be expedient to accept some tactical support from the 65% who are conservatives if your purpose is to isolate Islamism in general and jihadism in particular. Going by what Mr Nawaz's think-tank and others in that ideological camp argue quite a lot of the time, then the 10% who are reformers must eschew all conservatives and fight a relentless, lonely ideological battle to win over the remaining 90% of Muslims to their way of thinking.

Either proposition sounds like a pretty tall order, although the second is, objectively speaking, quite a lot harder than the first. No wonder Mr Harris is politely sceptical.