In this first installment of the translation of the correspondence between Ibn Sina and al-Biruni, al-As'ilah wa'l-Ajwibah, Ibn Sina responds to the first question posed to him by al-Biruni who criticizes reasons given by Aristotle for denying levity or gravity to the celestial spheres and the Aristotelian notion of circular motion being an innate property of the heavenly bodies.
Keywords: Ibn Sina-al-Biruni correspondence; criticism of Aristotelian natural philosophy; De Caelo; ...