Ṣāʾin al-Dīn ibn Turka al-Iṣfahānī (d. 1432) is among the most neglected figures in the history of Arabic-Islamic philosophy. True, his Tamhīd al-qawāʿid (“Introduction to the Principles,” TQ) has been highly evaluated within the Iranian ʿirfān circle since the late Qajar period; as the author of TQ, he is considered in this circle to be a precursor of Mullā Ṣadrā’s (d. 1640) alleged “synthesis” of Ibn al-ʿArabī’s (d. 1240) Akbarian mysticism, al-Suhrawardī’s (d. 1191) illuminationist philosophy, and al-Ṭūsī’s (d. 1274) revived Avicennian philosophy. Modern historians, however, adopt this evaluation while conducting, effectively, no detailed analysis of the contents of the work. Even Melvin-Koushki, who explores in detail the lettrist-occultist dimensions of this politically afflicted polymath’s Weltanschauung, has not gone so far as to redress their inaccurate understanding of TQ itself.
In this paper, I will focus on two central issues addressed in TQ: 1) that “absolute theology” (al-ʿilm al-ilāhī al-muṭlaq) is the highest science, whose subject-matter is “existence” (wujūd) as such; and 2) that existence is the Real (al-ḥaqq). What is noteworthy is that Ibn Turka discusses both issues with (critical) reference to major philosophical texts, such as the Ilāhiyyāt of Ibn Sīnā’s (d. 1037) Shifāʾ (on his conception of metaphysics as the regina scientiarum), al-Suhrawardī’s Ḥikmat al-ishrāq (on his thesis that existence is a mental construct), and the Ṭabīʿiyyāt of al-Ṭūsī’s Sharḥ al-Ishārāt (on his theory of the prerequisites for something being analogical). By analysing Ibn Turka’s arguments on the aforementioned two issues while clarifying his positions towards the theses of earlier philosophers, I aim in the present study to indicate the place of this late medieval Akbarian mystic in the post-Avicennian history of philosophy.
