ṬŪSĪ, NAṢĪR AL-DĪN. Naṣīr al-Dīn Ṭūsī (Muḥammad ibn Muḥammad ibn Ḥasan, AH 597–672/1201–1274 CE), addressed in general Islamic literature as khawājah (master) and the muḥaqqiq (scholar) of Ṭūs, was a Persian Shīʿī philosopher, theologian, mathematician, astronomer, and statesman. He is by far the most celebrated scholar of the thirteenth century in eastern Islamic lands. Very little is known about his childhood and early education, apart from what he reveals in his autobiography, the Sayr wa sulūk. He was born in Ṭūs, in northeastern Iran into an Ithnā ʿasharī (Twelver) Shīʿī family and died in Baghdad. He lost his father at a young age. Fulfilling the wish...