includes in his writings both worthless and worthwhile material, and cites many weak and fabricated hadiths to serve his own ends. He tailored his writings to what people wanted: he would write for the Shi'a what suited them so that they would reward him, and he would write according to the school of Abū Hanīfa for certain kings in order to achieve his aims. His method was thus like that of the preacher who was asked, “Which school do you follow?” He replied, “In which city?”

For this reason, some of his books contain [disparagement](1) of the Rightly Guided Caliphs and other Companions—may Allah be pleased with them—to curry favor with(2) those among the Shi'a whom he sought to please thereby, while some of them contain praise of the Rightly Guided Caliphs and others.

Accordingly, since the hadith commonly known among the early and later generations(3) states that the Prophet—may Allah bless him and grant him peace—said concerning the Mahdī:

“His name will correspond to mine, and his father’s name to my father’s,”

many people aspired(4) to be the Mahdī themselves. Indeed, al-Mansūr named his son Muhammad and gave him the title al-Mahdī, thereby making his son’s name correspond to the Prophet’s name(5), and his father’s name to the Prophet’s father’s name. He was not, however, the one who had been promised.

Abū Abd Allah Muhammad ibn Tūmart [who bore the title al-Mahdī, appeared in the Maghreb, gave his faction the title al-Muwahhidūn (the affirmers of divine oneness), and whose history is well known, used to claim that he was the Mahdī](6) who had been foretold. His followers would deliver sermons in his name from their pulpits, saying in