Iraq in the tenth and eleventh centuries witnessed aflowering of Shiite cultural production with lastingeffects on the Islamic sciences such as law, hadith,theology, and Qur'anic commentary. The works ofal-Shaykh al-Mufīd (d. 413/1022), al-Sharīfal-Murtaḍā (d. 436/1044), and al-Shaykh al-Ṭūsī (d.460/1067) not only broke significant new ground inShiite intellectual history and defended Shiitedoctrinal positions against opponents, but also setparameters for production in these fields that wouldremain in effect, grosso modo,until modern times. During the same period, Shiiteauthors made substantial contributions to fields notdirectly related to Shiite religious doctrine,playing a crucial role in elaborating and preservingIslamic heritage in general. Al-Masʿūdī's (d.345/956) famous history Murūjal-dhahab and Abū al-Faraj al-Iṣfahānī's(d. 356/967) collection of songs, poetry, andassociated lore, Kitāb al-Aghānī,are prominent examples of Shiite authors'contributions to general Arabo-Islamic culturalproduction. Arguably yet more important is theFihrist, composed in Baghdad in377-378 ah/987-988 ce by Ibnal-Nadīm, an Imāmī Shiite bookseller. This work, acomprehensive catalogue of Arabic book titles, iswidely recognised as one of the most importantsources for the history of all learned disciplinesrecorded in Arabic in the course of the first fourIslamic centuries. As a consequence, the presentunderstanding of entire swaths of Islamicintellectual history, including the rise anddevelopment of Muʿtazilī theology and thetranslation of the Greek sciences into Arabic, isheavily indebted to a Shiite author.