 The Ladder Argument is a rehabilitation of an Aristotelian argument presented in De Caelo (I.5, 271b26–272a7). Avicenna discusses this argument in the Physics of “The Healing” (Avicenna [Ph2]: chap. III.8, [7]). The argument has been the subject of a long-standing debate in post-Avicennian philosophy (McGinnis 2018). The argument was criticized by, among others, Abū al-Barakāt in his Al-Muʿtabar (vol. 2, 84–86) and Najm al-Dīn al-Kātibī al-Qazwīnī (d. 1277) in his Ḥikma al-ʿayn ([2002: 38–39]). On the other hand, defenses of the Ladder Argument can be found in, among others, al-Ṭūsī’s commentary on Avicenna’s Pointers and Reminders (in Avicenna [Pointers]: namaṭ I, 183–191) and Mullā Ṣadrā’s commentary on al-Abharī’s Hidāya (Sharḥ Al-Hidāya al-Athīrīya, 65–69).