Naṣīr al-Dīn al-Ṭūsī’s Taʿdīl al-miʿyār (Recalibrating the Measure): English Translation and Commentary

• Applicant: Behnam Zolghadr, Ph.D.
• Subject Area: History of Philosophy ; Islamic Studies, Arabian Studies, Semitic Studies
• Term: since 2024
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 540080154

This project is about Nasîr al-Dīn al-Ṭûsî’s Ta’dīl al-mi’yâr (Recalibrating the Measure). The Ta’dîl is one of the most important logical texts of thirteenth-century Arabic logic, which represents one of the most dynamic periods in the history of Arabic logic. This century saw a confrontation between two groups of Arabic logicians: the revisionists who revised Avicennian logic and deviated from Avicenna on several points, and the purists, who defended Avicenna’s original logical ideas against the revisionists. Atîr al-Dîn al-Abharî (d. 1365), along with Afdal al-Dîn al-Hûnagî, is one of the most important revisionist logicians, while Ṭûsî (d. 1376) is the pioneer figure among the purists. Ṭûsî’s Ta’dîl al-mi’yâr, which is a systematic criticism of Abharî’s Tanzîl al-afkar fī ta’dîl al-asrâr (The Revelation of Thoughts in Recalibrating Secrets), is one of the earliest and arguably the most comprehensive confrontation between an orthodox Avicennian logician, namely Ṭûsî, and a revisionist Arabic logician, namely Abharî. Ṭûsî’s objections to Abharî made a crucial contribution to later developments and debates in Arabic logic as well as to the applications of Arabic logic in other Islamic disciplines. Thus, the study of this work is crucial to all studies of Arabic logic and its applications in this period and after. The outcome of this project will be the first complete English translation of Tûsî’s Ta’dīl al-mi’yār, along with a commentary. The commentary is intended to serve three general purposes: First, it explains and clarifies the arguments and claims of the text, both Abharîs lemmas and Ṭûsî’s objections. Second, the planned commentary explains the grounds of Abharî’s ideas in each case. This will clarify Hûnagî’s influence on Abharî, and Abharî’s deviation from Hûnagî (d. 1248). Third, the commentary evaluates Ṭûsî’s defence of Avicenna’s logical ideas against the revisionist ideas of Abharî. There are several studies on the logic of the early revisionists such as Hûnagî and Râzî (d. 1210) and on the later confrontations between the revisionists and the purists, such as the commentaries on Kâtibî’s (d. 1276) Samsiyya. However, there is still a large gap in the studies on the Arabic logic of this period, especially concerning the early confrontations between the revisionists and the purists. The publications to come out of this project will fill this gap. The work builds on a previous DFG-funded project, in which I present a comprehensive account of Hûnagî’s logic. Abharî adopted many of Hûnagî's logical ideas while rejecting others, and so Tûsî in his Ta’dīl al-mi’yâr responds not only to Abharî but also to Hûnagî.

• DFG Programme: Research Grants