Much ink has been spilled on the tumultuous life and works of Naṣīr al-Dīn Ṭūsī. This paper re-evaluates his connections with Sufism and Ismāʿīlism, and challenges the reduction of the former to a late interest, and the latter to an early affiliation abandoned in the wake of the Mongol invasion. The paper argues that Sufi and Ismāʿīlī themes, sources, and ideas are in an organic interpenetration in Ṭūsī’s works throughout his career. While his early Ismāʿīlī eschatology has a fundamentally Sufi nature, his late Sufi treatise adopts the key components of Ismāʿīlī negative theology of the divine nature. The case of Ṭūsī illustrates that the Ismāʿīlī double negation was preserved in Iran and Central Asia, and put into creative interactions with Sufism in the thirteenth century.
- Nasị̄ r al-Dīn Ṭūsī