IN DEFENCE OF THE SOVEREIGNTY OF PHILOSOPHY: AL-BAGHDADI'S CRITIQUE OF IBN AL-HAYTHAM'S GEOMETRISATION OF PLACE ¹

Abstract

This paper investigates the objections that were raised by the philosopher ‘Abd al-La[tdotu ]if al-Baghdadi (d. ca. 1231 CE) against al-[Hdotu ]asan ibn al-Haytham’s (Alhazen; d. after 1041 CE) geometrisation of place. In this line of enquiry, I contrast the philosophical propositions that were advanced by al-Baghdadi in his tract: Fi al-Radd ‘ala Ibn al-Haytham fi al-makan (A refutation of Ibn al-Haytham’s place), with the geometrical demonstrations that Ibn al-Haytham presented in his groundbreaking treatise: Qawl fi al-Makan (Discourse on place). In examining the particulars of al-Baghdadi’s fragile defence of Aristotle’s definition of topos as delineated in Book IV of the Physics, which was rejected on mathematical grounds by Ibn al-Haytham, a special attention is also given to highlighting the systemic distinctions between the entities that are studied within the speculative physical doctrines of common sense and immediate experience, and the postulated ‘objects’ of scientific and mathematical research.

Footnotes

¹ An earlier concise version of this paper was presented on 18 February 2006 in Florence, under the title: ‘The physical or the mathematical? interrogating al-Baghdadi's critique of Ibn al-Haytham's geometrisation of place’, as part of the Colloque de la Société Internationale d'Histoire des Sciences et des Philosophies Arabes et Islamiques (Circulation des savoirs autour de la Méditerranée, IX^e–XVI^e siècles), which was held in association with the University of Florence. This text will be published as part of the Proceedings of the Colloquium (Les Actes du Colloque), under the editorship of Graziella Federici Vescovini (Florence).