Refutation of a Threatening Heresy, i.e. the Epistles of the Brethren in Purity

At-Tawhidi's 17th Night : Refutation of a Threatening Heresy, i.e. the Epistles of the Brethren in Purity. The 17th night of the Kitab al-imtawa-l-muanasa written by Abuayyan at-Tawidi can no longer be considered as a testimony on the authorship of the Rasail Ikhwan a-afa, for the very epistles were already written around 307/920. Indeed, they were well-known in Andalusia in the West around the middle of the century, and among the Ismailis in the East already at its beginning. Furthermore, we can demonstrate that their doctrine would be anachronistic out of the late third/ninth century. Then, the 17th night must be reinterpreted as the rebuttal of the Brethren in Purity's views in a very structured manner employing different characters : the minister Ibn Sadan, al-Bukhari, Zayd b. al-Rifaa, al-Maqdisi, an-Nisaburi and al-Balkhi, in order to represent the different degrees of initiation and symbolize progression of the heresy.