Called to exercise his medical skill at the court of Nuh b. Mansur, the Samanid governor of Khurasan, he enjoyed that prince’s favour, and in his library studied many works of Aristotle hitherto unknown to his contemporaries, and when that library was burned he was regarded as the sole transmitter of the doctrines contained in those books. This represents contemporary Arabic opinion about him: there is no evidence in his existing writings that he had access to Aristotelian material other than that generally known to the Syriac and Arabic writers. When the affairs of the Samanid dynasty fell into disorder Ibn Sina removed to Khwarazan, where he, with several other scholars, enjoyed the enlightened patronage of the Ma´muni Emir. But this Emir was living a somewhat precarious existence in the neighbourhood of the Turkish Sultan Mahmud of Ghazna, the stern champion of orthodoxy and the conqueror of India. It was obvious that the Sultan coveted the Emir’s dominions, and that when he chose to seize them it would be impossible to resist; he actually did take them in 408. Meanwhile the Sultan was treated with the utmost deference by the Emir and such of his neighbours as were allowed to live on sufferance. Mahmud wished to be distinguished as a patron of learning, and “invited” scholars to his court--in plain words, he kidnapped scholars and took care that they never afterwards transgressed the strictest limits of orthodoxy. Amongst others the Emir received a letter inviting such men of learning as were to be found in Khwarazan to his court. The Emir read out the letter to the five most distinguished scholars who were his guests, leaving them to act as they thought fit. Three of the guests were attracted by the Sultan’s reputation for generosity and accepted the invitation, but two, Ibn Sina and Masihi, were afraid to venture, so they escaped privately and fled; overtaken by a sandstorm in the desert Masihi perished, but Ibn Sina, after long wanderings, finally found a refuge in Isfahan, where the Buwayhid `Ala´u d-Dawla Muhammad held his court. His experiences show plainly that it was the Shi`ites who were the supporters of philosophy, and that the growing Turkish power of Mahmud of Ghazna and of the Seljuks who succeeded him was reactionary and unfavourably disposed towards philosophical research. It was the Turkish power which finally checked the progress of Arabic philosophy in the East.