عنوان مقاله [English]
Date of writing of Rasa’il Ikhwan al-Safa and its writers are not obvious. Because of these ambiguities, there are several ideas on this issue. It seems that dateline of Rasa’il, entered a new stage of research with critical article of Paul Casanova that was full of historical and astrological computations. Of course there were other suggestions with different methods against Casanova. Anyway, Abbas Hamdani has criticized and made a correction Casanova’s theory in final decade of 20 century. He has neglected some imperfections and offered new hypothesis and results. His idea is still one of accepted opinions on dateline of Rasa'il, in Ismailit circles. this present article offered a short definition of Hamdani and Casanova’s ideas at first. Then it has explained the mistakes and ambiguities which are in Hamdani’s conclusion by focused on his commentaries on some part of Rasa’il. This critical review has been done in two parts: problem of astrological predictions in Rasa’il and problem of appointed Mahdi’s return. Finally, after explaining the unqualified interpretations of Hamdani on Rasa’il, his opinion about propagandistic character of Rasa'il in advantage of establishing Fatimid Caliphate, is hesitated.