Among them was one who reached the highest rank in his arts, and the chief Ibn Sina, whose books were studied, and whose words were benefited from, and by whose guidance they proceeded and composed. And the treasurer of Sayf al-Dawla's books was al-Khalidin, and his poet was al-Muthanna. And it appears that al-Muthanna was also a Shi'ite, and even a Qarmatian, as will be seen. And the influence of the Alawites and their teachings was vast and great, and among the effects of this influence was the discussion and debate between the Fatimid Da'i al-Du'at and Abu al-Ala al-Ma'arri, which would take a long time to explain. Al-Ghazali named their doctrine "Ta'limi," and mentioned them when he was compelled to know whether the truth was with the jurists, or the philosophers, or the Ta'limis. By Ta'limis, he meant these Shi'ites. Then he did not like any of that, and finally he became a Sufi and responded to the Shi'ites. And the meaning of Ta'limi is those who rely absolutely on the authority of the Imam, and that he is the source of teaching and guidance, and he is the Mahdi. In any case, this state was founded on the idea of the Mahdiya, and their lands were the strongest center of Shi'ism. This Shi'ism of theirs was a bond between them and the Persians, who supported them due to their Shi'ism as well, and they supported them because they were descended from Fatima and Ali. As for their affection for Ali, it is because, as historians say, he married his daughter al-Husayn to the daughter of Yazdegerd.