Given that it was nearly lost to history – only available in a unique manuscript held in Tehran – Sharastani’s commentary (dating from 540 AH/1145 CE) is a peculiarly exciting survival of the medieval literature on the Holy Qur’an. Its value mainly rests on three things. Firstly, its author enjoys a very high reputation as a scholar and thinker in the wider annals of Muslim intellectual history. He is better known as a Sunni theologian of remarkable subtlety, and as one of the great medieval authorities, in east or west, on the world’s religious denominations and philosophical doctrines. The recovery of his commentary on the Holy Qur’an, a summit in any Muslim thinker’s oeuvre due to the sheer prestige and foundationality of the sacred text within the overall tradition, completes our picture of a great mind. Secondly, while the commentary includes a wealth of valuable data transmitted on the scripture up to Shahrastani’s period, at its core is a unique set of interpretive ‘keys’ on the basis of which the author claims to lay bare a structure of ideas deep within the text – a virtual ‘philosophy’ of the Holy Qur’an. This central aspect of Sharastani’s Keys to the Arcana amounts to a great intellectual achievement, and one which is now timely. It opens up the depths of the sacred text to modern appreciation: an interpretive system which brings out an unsuspected intelligibility deep within the Holy Qur’an. Thirdly, this system is demonstrably of Ismaili origin, and Keys to the Arcana is thus major evidence for the truth of the claim of some of its author’s contemporaries, that he was secretly a Nizari Ismaili.

The volume contains an English translation of Shahrastani’s twelve introductory chapters, and his verse by verse commentary on the opening chapter of the Holy Qur’an, Surat al-Fatiha. Copious annotation is provided, with an extended introduction by the translator. A fully cross-referenced Arabic edition of the text is included. This multifaceted volume has been a painstaking scholarly project. The result provides an English-speaking readership with full access to a lost gem of the Muslim heritage.