Naṣīr al-Dīn al-Ṭūsī

Persian philosopher, Shīʿī theologian and astronomer, founder of the Maragha observatory, who defended Ibn Sīnā’s logic against the innovations of al-Khūnajī, al-Abharī and al-Kātibī.

Life

Al-Ṭūsī was born in Ṭūs on 11 Jumādā I 597 (17 February 1201). After studying with his father he travelled at about fifteen to the centres of learning; in Nishapur he studied law with Muʿīn al-Dīn Sālim b. Badrān al-Miṣrī and philosophy with Farīd al-Dīn Dāmād, with whom he read the works of Ibn Sīnā, above all al-Ishārāt wa-l-tanbīhāt. Tony Street and Nadja Germann add that he read Fakhr al-Dīn al-Rāzī’s commentary on the Ishārāt under al-Abharī. His fame brought an invitation from the Ismāʿīlī governor of Quhistān, Nāṣir al-Dīn Muḥtasham, in whose service he wrote his commentary on the Ishārāt and his Persian ethics, Akhlāq-i Nāṣirī; later he lived, partly as a prisoner, at the Ismāʿīlī stronghold of Alamūt.

When the Mongols besieged Alamūt he advised its lord to surrender to Hülegü, whose favour he then won; he accompanied the campaign against Baghdad. The TDV İslâm Ansiklopedisi notes that the accusation, made by Ibn Taymiyya and Ibn Qayyim al-Jawziyya, that the last caliph was killed on his advice is not found in the detailed sources on the fall of Baghdad. Hülegü funded the observatory at Maragha, completed in 657/1259, where al-Ṭūsī gathered scholars in many fields, among them Quṭb al-Dīn al-Shīrāzī and Najm al-Dīn al-Kātibī. He died in Baghdad on 18 Dhū al-Ḥijja 672 (25 June 1274) and was buried near the shrine of Mūsā al-Kāẓim.

In logic he was, in Street and Germann’s words, ‘a particularly interesting logician’: he came to Ibn Sīnā through al-Rāzī’s students but developed ‘a deeper respect for Avicenna’s formulations than any of his contemporaries’. His commentary on the Ishārāt answers al-Rāzī’s criticisms (he relayed a description of al-Rāzī’s work as ‘a butchery, not a commentary’), while acknowledging its value. In Taʿdīl al-miʿyār he assessed al-Abharī’s Tanzīl al-afkār, which had adopted positions of al-Khūnajī, and he continued the debate in exchanges with al-Kātibī. Against al-Khūnajī’s view that the of logic is conceptions and assents, he held to Ibn Sīnā’s answer: the secondary intelligibles insofar as they lead from the known to the unknown. His Persian Asās al-iqtibās and his Tajrīd al-manṭiq set out Avicennan logic at length.

Street calls al-Abharī, al-Kātibī and al-Ṭūsī ‘certainly among the greatest logicians of the thirteenth century’ and argues that al-Kātibī’s Shamsiyya, though it departs from al-Ṭūsī on many points, arranges its material using the distinction between the form and the matter of arguments that al-Ṭūsī had identified in the order of the Ishārāt. The Shamsiyya so far replaced the logic of the Ishārāt that, Street notes, most manuscripts of the Ishārāt with al-Ṭūsī’s commentary copied after 1400 omit the logic section.

Uncertain or disputed

His relation to al-Kātibī: the TDV counts al-Kātibī among his students; Street treats them as near-contemporaries both trained by al-Abharī, suggesting that ‘perhaps at some time Ṭūsī had shared a class with Kātibī’.
The manner of his death: his student Ibn al-Fuwaṭī says in one place that he took his own life, but elsewhere that he died normally; Bar Hebraeus reports a rumour of poisoning. According to the TDV, the other sources do not confirm the story of suicide.
Whether Hülegü made him vizier is reported only by some sources (TDV).
His kunya Abū Jaʿfar may come from confusion with the earlier Imāmī scholar Abū Jaʿfar al-Ṭūsī (d. 460/1067) (TDV).

Works

Ḥall mushkilāt al-Ishārāt (Sharḥ al-Ishārāt) حَلُّ مُشْكِلَاتِ الإِشَارَاتِ — op Ibn SinaCommentary on Ibn Sīnā’s al-Ishārāt wa-l-tanbīhāt, defending it against Fakhr al-Dīn al-Rāzī; written in Quhistān.commentaar
Asās al-iqtibās أَسَاسُ الاقْتِبَاسِLarge Persian treatise on logic (Tehran 1375 Sh); translated into Arabic by Molla Hüsrev (TDV).werk
Tajrīd al-manṭiq تَجْرِيدُ المَنْطِقِShort Arabic exposition of logic (Beirut 1408/1988); commentary al-Jawhar al-naḍīd by al-ʿAllāma al-Ḥillī, printed in the late nineteenth century and used in Shīʿī seminaries (SEP).matn
Taʿdīl al-miʿyār fī naqd Tanzīl al-afkār تَعْدِيلُ المِعْيَارِ فِي نَقْدِ تَنْزِيلِ الأَفْكَارِ — op al-AbharīCritique of al-Abharī’s Tanzīl al-afkār; ed. in Manṭiq wa mabāḥith al-alfāẓ, Tehran 1353 Sh.werk
Exchanges with al-Kātibī (Muṭāraḥāt)Correspondence on logic and on the proof of the Necessary Existent; the latter ed. Āl Yāsīn as al-Muṭāraḥāt al-falsafiyya (Baghdad 1956).werk
Tajrīd al-iʿtiqād تَجْرِيدُ الاعْتِقَادِHis main work of philosophical theology, the founding text of Imāmī philosophical kalām (TDV).matn
Taḥrīr al-Majisṭī and Akhlāq-i NāṣirīRecension of Ptolemy’s Almagest and Persian work on ethics.werk

Reception

The TDV notes that later scholars such as al-Taftāzānī, al-Jurjānī, Mīr Dāmād, Mullā Ṣadrā and Molla Fenârî cite him as a ‘verifier’ (muḥaqqiq), and that Taşköprüzâde regarded him as the first to combine kalām fully with Peripatetic philosophy.

Street and Germann note that Shīʿī seminaries turned to the logic of al-Ṭūsī and al-Ḥillī in the nineteenth century, while Sunni madrasas kept to al-Abharī and al-Kātibī.

Chains of transmission for the Ishārāt still pass through him: the twentieth-century Meccan scholar Yāsīn al-Fādānī recorded one running from al-Jurjānī through Quṭb al-Dīn al-Rāzī and Quṭb al-Dīn al-Shīrāzī to al-Ṭūsī (Fanani and Widigdo).

Sources (5)