- In full:
- Muḥammad ibn Muḥammad ibn al-Ḥasan al-Ṭūsī
- Born:
- Feb. 18, 1201,, Ṭūs, Khorāsān [now Iran]
- Died:
- June 26, 1274, Baghdad, Iraq (aged 73)
- Notable Works:
- “Akhlāq-i Naṣīrī”
Naṣīr al-Dīn al-Ṭūsī
-
Who was Naṣīr al-Dīn al-Ṭūsī?
Naṣīr al-Dīn al-Ṭūsī (1201–1274) was a Persian philosopher, scientist, and mathematician. He was educated in Ṭūs and Neyshābūr. Around 1227, he found sanctuary in the mountain fortresses of Khorāsān and dedicated his famous work, Nasirean Ethics, to the governor.
Al-Ṭūsī accepted a position with the Mongols as a scientific advisor in 1256 after the fall of Alamūt. He was later put in charge of religious bequests. Benefiting from Hulegu’s belief in astrology, Al-Ṭūsī got support to build an observatory in Marāgheh. He wrote around 150 books in both Arabic and Persian. He also edited definitive Arabic versions of works by Euclid, Archimedes, Ptolemy, Autolycus, and Theodosius and made original contributions to both mathematics and astronomy.
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When and where did he live?
Naṣīr al-Dīn al-Ṭūsī, a Persian scholar, was born in Ṭūs, Khorāsān (now Iran), on February 18, 1201, and he died in Baghdad, Iraq, on June 26, 1274. He was educated in Ṭūs and Neyshābūr. Al-Ṭūsī found sanctuary in the mountain fortresses of Khorāsān and was later invited to stay in Alamūt. After the fall of Alamūt, he accepted a position with the Mongols and, in 1259, obtained support to build an observatory in Marāgheh (now in Azerbaijan).
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What subjects did al-Ṭūsī study and write about?
Naṣīr al-Dīn al-Ṭūsī was a Persian scholar who studied and wrote about a wide array of subjects, including philosophy, science, and mathematics.
Al-Ṭūsī wrote on Ismāʿīlite theology (Taṣawwurāt), logic (Asās al-iqtibās), and mathematics (Taḥrīr al-Majisṭī). His Zīj-i Ilkhānī is an accurate table of planetary movements, and his Tadhkirah fi ʿilm al-hayʾa describes the al-Ṭūsī couple, which reforms Ptolemaic planetary models. His Tajrīd is a highly esteemed treatise on Shīʿite theology.
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How did al-Ṭūsī contribute to mathematics and astronomy?
Naṣīr al-Dīn al-Ṭūsī was a Persian polymath who made significant contributions to mathematics and astronomy. Al-Ṭūsī created trigonometry as a distinct mathematical discipline separate from astronomy. Also, he edited definitive versions of works by Euclid, Archimedes, Ptolemy, Autolycus, and Theodosius.
Al-Ṭūsī's Zīj-i Ilkhānī is a highly accurate table of planetary movements based on his research at the Marāgheh observatory. His most influential book in the West may have been Tadhkirah fi ʿilm al-hayʾah, which describes the al-Ṭūsī couple, a geometric construction that produces rectilinear motion from a point on one circle rolling inside another. With this construction, Al-Ṭūsī reformed Ptolemaic planetary models, creating a system where all orbits are described by uniform circular motion.
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What is the significance of the observatory he built at Maragheh?
Naṣīr al-Dīn al-Ṭūsī, a Persian scholar, built an observatory at Maragheh in 1259, which was completed in 1262. Al-Ṭūsī obtained support to build the observatory because of Hulegu’s belief in astrology. More than just an observatory, it also had a first-rate library and employed notable Islamic and Chinese scholars. Research continued at the institution for at least 25 years after al-Ṭūsī’s death, and some of its astronomical instruments inspired later designs in Samarkand. The observatory sparked a revival of Islamic mathematics, astronomy, philosophy, and theology.
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How have al-Ṭūsī’s works influenced science and learning today?
Naṣīr al-Dīn al-Ṭūsī (1201–1274) was a Persian polymath whose works significantly influenced science and learning. His most influential book in the West, Tadhkirah fi \u02bfilm al-hay\u02bfa (“Treasury of astronomy”), introduced the al-\u1e6c\u016bs\u012b couple, which reformed Ptolemaic planetary models by using uniform circular motion for all orbits.
Al-\u1e6c\u016bs\u012b's observatory at Marāgheh sparked a revival in Islamic mathematics, astronomy, philosophy, and theology. The astronomical models developed there may have inspired Nicolaus Copernicus. Al-\u1e6c\u016bs\u012b also helped establish trigonometry as its own mathematical discipline, separate from astronomy.
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Naṣīr al-Dīn al-Ṭūsī (born Feb. 18, 1201, Ṭūs, Khorāsān [now Iran]—died June 26, 1274, Baghdad, Iraq) was an outstanding Persian philosopher, scientist, and mathematician.
Educated first in Ṭūs, where his father was a jurist in the Twelfth Imam school, the main sect of Shīʾite Muslims, al-Ṭūsī finished his education in Neyshābūr, about 75 kilometres (50 miles) to the west. This was no doubt a prudent move as Genghis Khan (d. 1227), having conquered Beijing in 1215, turned his attention to the Islamic world and reached the region around Ṭūs by 1220. In about 1227 the Ismāʿīlīte governor Nāṣir al-Dīn ʿAbd al-Raḥīm offered al-Ṭūsī sanctuary in his mountain fortresses in Khorāsān. Al-Ṭūsī in turn dedicated his most famous work, Akhlāq-i nāṣirī (1232; Nasirean Ethics), to the governor before being invited to stay in the capital at Alamūt, where he espoused the Ismāʿīlīte faith under the new imam, Alauddin Muḥammad (reigned 1227–1255). (This Ismāʿīlīte state began in 1090 with the conquest of Alamūt by Ḥasan-e Ṣabbāḥ and ended with the fall of the city to the Mongols in 1256.) During this period, al-Ṭūsī wrote on Ismāʿīlīte theology (Taṣawwurāt; “Notions”), logic (Asās al-iqtibās; “Foundations of Inference”), and mathematics (Taḥrīr al-Majisṭī; “Commentary on the Almagest”).
With the fall in 1256 of Alamūt to Hülegü Khan (c. 1217–1265), grandson of Genghis Khan, al-Ṭūsī immediately accepted a position with the Mongols as a scientific adviser. (The alacrity with which he went to work for them fueled accusations that his conversion to the Ismāʿīlīte faith was feigned, as well as rumours that he betrayed the city’s defenses.) Al-Ṭūsī married a Mongol and was then put in charge of the ministry of religious bequests. The topic of whether al-Ṭūsī accompanied the Mongol capture of Baghdad in 1258 remains controversial, although he certainly visited nearby Shīʾite centres soon afterward. Profiting from Hülegü’s belief in astrology, al-Ṭūsī obtained support in 1259 to build a fine observatory (completed in 1262) adjacent to Hülegü’s capital in Marāgheh (now in Azerbaijan). More than an observatory, Hülegü obtained a first-rate library and staffed his institution with notable Islamic and Chinese scholars. Funded by an endowment, research continued at the institution for at least 25 years after al-Ṭūsī’s death, and some of its astronomical instruments inspired later designs in Samarkand (now in Uzbekistan).
Al-Ṭūsī was a man of exceptionally wide erudition. He wrote approximately 150 books in Arabic and Persian and edited the definitive Arabic versions of the works of Euclid, Archimedes, Ptolemy, Autolycus, and Theodosius. He also made original contributions to mathematics and astronomy. His Zīj-i Ilkhānī (1271; “Ilkhan Tables”), based on research at the Marāgheh observatory, is a splendidly accurate table of planetary movements. Al-Ṭūsī’s most influential book in the West may have been Tadhkirah fi ʿilm al-hayʿa (“Treasury of astronomy”), which describes a geometric construction, now known as the al-Ṭūsī couple, for producing rectilinear motion from a point on one circle rolling inside another. By means of this construction, al-Ṭūsī succeeded in reforming the Ptolemaic planetary models, producing a system in which all orbits are described by uniform circular motion. Most historians of Islamic astronomy believe that the planetary models developed at Marāgheh found their way to Europe (perhaps via Byzantium) and provided Nicolaus Copernicus (1473–1543) with inspiration for his astronomical models.
Today al-Ṭūsī’s Tajrīd (“Catharsis”) is a highly esteemed treatise on Shīʾite theology. He made important contributions to many branches of Islamic learning, and under his direction Marāgheh sparked a revival of Islamic mathematics, astronomy, philosophy, and theology. In the East, al-Ṭūsī is an example par excellence of the ḥakīm, or wise man.