Dispute on the Generation and Corruption of the Celestial Spheres: A Methodological Analysis

This study provides a methodological analysis of the historic correspondence between two eminent intellectual figures of the medieval Islamic world, Abū Rayḥān al-Bīrūnī and Ibn Sīnā (Avicenna, focusing on their debate concerning the applicability of generation and corruption to the celestial spheres. The core of this inquiry lies in al-Bīrūnī's scientifically-motivated challenge to the dominant Aristotelian doctrine, which posited the eternal and immutable nature of the supralunary world. Our analysis concentrates specifically on the cosmological dimension of their dispute, moving beyond its philosophical underpinnings to scrutinize the fundamental methodological approaches each scholar employed. The investigation demonstrates that the former, grounding his argument in empirical observations of terrestrial phenomena such as the gradual alteration of mountains, constructed an inductive rationale. He sought to extend a principle verified in the sublunary realm to the heavens, thereby contesting a key element of the established cosmological paradigm. The latter, in contrast, mounted a rigorous defense of the classical framework, countering this proposed generalization with deductive reasoning rooted in Aristotelian physics and metaphysics. This methodological clash not only highlights a pivotal moment in the history of science but also epitomizes the tension between emerging empirical tendencies and entrenched philosophical system-building. The study ultimately reveals how this intellectual exchange tested the boundaries of the Aristotelian paradigm from within, using its own conceptual tools to question the absolute qualitative divide between the celestial and terrestrial domains.