The premise that Islam is something that can be a closed or an open religion may not be the best one. Islam, in its many forms, methods and practices, is a reflection of the person who practises it (just like any other religion). If your view on dealing with other people and their faiths and intellectual backgrounds is rigid and closed, then your practice of Islam or whatever faith you practise will also be rigid and closed. There are innumerable ways to approach one’s spiritual relationship and so the question will be whether those who claim to be adherents of Islam will take a rigid approach as opposed to an ostensibly open one. That is a function of many issues—economic, social, cultural and, of course, political. In societies where we perceive Muslims as being closed, they are often subject to repressive regimes (both secular and religious) where their closed practice of Islam is highly correlated to the nature of their rigid society, with limited basic freedoms (expression, speech and, yes, even religion).