very, Ismailism, the faith of the Fatimid aristocracy was excepted as the true faith by only a small number of the empires citizens. It was not only the sparse numbers of the Ismailis that drove them towards such freedoms, but Ismailism itself. for further reading on ismailism I would go with (http://www.amazon.com/gp/search?index=books&linkCode=qs&keywords=9780199557240)