Monotheism—a term coined in the seventeenth century by the Cambridge Platonist Henry More (1614–1687) and commonly associated with metaphysics and classical theism—continues to provoke philosophical and theological debate. This article examines the Qurʾānic argument for monotheism, whose probative force was judged weak by the Māturīdī theologian Saʿd al-Dīn al-Taftāzānī (d. 792/1390). It opens with a philosophical question: if cosmic order entails divine unity, does cosmic disorder entail divine plurality? While an affirmative answer has often been assumed, al-Taftāzānī’s logical analysis of Qurʾān 21:22 (“Had there been gods besides God in heaven and earth, both would have fallen into ruin”) generated sustained controversy among Sunnī theologians and later commentators, including Maḥmūd al-Ālūsī (d. 1270/1854) and Jamāl al-Dīn al-Qāsimī (d. 1332/1914). This study revisits the burhān al-tamānuʿ by analyzing the counterfactual conditional structure of the Qurʾānic argument and tracing the debates it provoked within the Islamic theological tradition
