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Born  Nīshāpūr, (Iran)

Died  (Iran), 1329/1330

Niẓām al‐Dīn al‐Aʿraj al‐Nīsābūrī composed several widely studied astronomy texts in the 14th century, which indicate the integration of astronomy within a tradition of religious scholarship in Islamic civilization. He was born into a Shīʿa family with roots in Qum.

The sources say little about Nīsābūrī's early life and education. By mid‐1303, Nīsābūrī had begun to write Sharḥ Taḥrīr al‐Majisṭī (Commentary on the recension of the Almagest), a commentary on Naṣīr al‐Dīn al‐Ṭūsī's Taḥrīr al‐Majisṭī (Recension of the Almagest) of Ptolemy. As was true for many commentaries in Islamic science, Nīsābūrī did not simply explain the meanings of the original text but included the results of his own work as well. In the Sharḥ, Nīsābūrī devoted much space to observations of the obliquity of the ecliptic and to ʿUrḍī's work on instrument construction. Nīsābūrī also investigated whether Venus and Mercury had been observed to transit the Sun, an observation that would determine the position of the Sun with respect to Mercury and Venus. In 1304, Nīsābūrī arrived in Azerbaijan; by 1306 he was in Tabrīz, the largest city in Azerbaijan, where he completed the Sharḥ. In Tabrīz, Nīsābūrī also began to study with the astronomer Quṭb al‐Dīn al‐Shīrāzī.

Nīsābūrī completed his second major text, Kashf‐i ḥaqāʾiq‐i Zīj‐i Īlkhānī (Uncovering of the truths of the Īlkhānid astronomical handbook), in 1308/1309. The Kashf, a commentary on Ṭūsī's astronomical handbook entitled Zīj‐i Īlkhānī, refers to the Sharḥ. Nīsābūrī wrote the Kashf right after the Sharḥ inasmuch as the Kashf focused on topics that were closely connected to the Sharḥ, such as the observation and prediction of planetary positions.

The Tawḍīḥ al‐Tadhkira (Elucidation of the Tadhkira), a commentary on Ṭūsī's al‐Tadhkira fī ʿilm al‐hayʾa (Memento on astronomy), was Nīsābūrī's third and final text on astronomy. A cross‐reference to a Tadhkira commentary in the Sharḥ shows that Nīsābūrī had begun to compose the Tawḍīḥ before he finished the Sharḥ.

In the Tawḍīḥ, Nīsābūrī investigated theoretical topics, such as non‐Ptolemaic models for planetary motions, and topics that combined theory and observations, such as physical hypotheses that accounted for the observed variations in the obliquity of the ecliptic. Although the Sharḥ and the Tawḍīḥ evinced a mastery of the technical innovations of Islamic astronomy, Nīsābūrī did not make significant advances with the most difficult questions. Shīrāzī, however, did, and the weight of Shīrāzī's reputation may explain the coincidence of the date of the appearance of the Tawḍīḥ with the date of Shīrāzī's death in 1311.

Īlkhānid ministers patronized Nīsābūrī's scientific work. The Īlkhānids were the descendents of Hülegü Khān (died: 1265), who had patronized the construction of the famous observatory at Marāgha, Azerbaijan, where both Ṭūsī and Shīrāzī worked. Nīsābūrī dedicated the Sharḥ to Khwāja Saʿd al‐Dīn Muḥammad ibn ʿAlī al‐Sāwajī. Sāwajī was chief minister (along with Rashīd al‐Dīn) under Īlkhānid Sultan Ghāzān (reigned: 1295–1304) and continued in that post until 1312 when Rashīd al‐Dīn had him executed. Shīrāzī's acquaintance with Sāwajī would have provided a way for Nīsābūrī to gain Sāwajī's patronage. There is a 1309 copy of the Kashf dedicated to al‐Sāwajī. Nīsābūrī dedicated the Tawḍīḥ to a certain ʿAli ibn Maḥmūd al‐Yazdī.

Because the Sharḥ and the Tawḍīḥ were clearly written and intended for nonexpert astronomers, they became important components of a tradition of religious scholarship that included astronomy. Many manuscripts of the Sharḥ and Tawḍīḥ have ownership statements from the libraries of madrasas (colleges of religious studies). Two reports attest to how the Tawḍīḥ was the most important text at Ulugh Beg's madrasa in Samarqand for the study of the Tadhkira. Later works on Islamic astronomy, also with madrasa library ownership statements, refer to Nīsābūrī as al‐shāriḥ (the commentator).

Nīsābūrī's best‐known text, his Quran commentary entitled Gharāʾib al‐Qurʾān wa‐raghāʾib al‐furqān (The curiosities of the Quran and the desiderata of the demonstration), demonstrates the importance of science for religious scholars. Nīsābūrī in general relied heavily on Fakhr al‐Dīn al‐Rāzī's (died: 1209) al‐Tafsīr al‐kabīr (The great commentary), but frequently disagreed with Rāzī about the use of science and philosophy (falsafa) to portray nature. The Gharāʾib reflected Nīsābūrī's scientific education and privileged the views of the natural philosophers ( falāsifa), while Rāzī had favored the positions of the theologians (mutakallimūn). Through subtle rewordings and emendations of scientific detail, Nīsābūrī rebutted Rāzī's critique of science and falsafa in his portrayal of nature. Nīsābūrī completed Gharāʾib in 1329/1330, a date which the bio‐bibliographers consider to be the date of his death.