The second period may be considered as stretching from the time of occultation of the Mahdi to the Mongol invasion, not only because of the great changes brought about by this event, but also because this last date corresponds to the life of Khwajah Naslr al-DIn al-Tusi. With this remarkable genius, who was an outstanding mathematician, astronomer and philosopher, Shi'ite theology reaches its height. He may, in fact, be con-sidered in many ways as the greatest of the Shi'ite theologians. This period is marked by the appearance of authoritative collections of Hadith and religious doctrine which form the very substance of Shi'ite religious life. It begins with Kulaini, the author of the Usui al-kafi which is the most outstanding com-pilation of the traditions of the Shi'ite Imams. It is also the age of Ibn Babuyah, Shaikh Mufid and Muhammad ibn Hasan al-Tusi who are the authors of the main traditional sources of Shi'ite religious sciences. Also during this period Sayyid Sharif al-Radi compiled the sayings of 'All in the Nahj al-baldghah which after the Quran and prophetic Hadith is the mostimportant work in Shi'ism.

Ideals and realities of Islam On page 161 Saturday, January 5, 2013 @ 4:45pm