LAUSR

The present paper is devoted to the famous letter exchange between al-Bīrūnī and Avicenna. Its main concern is to elaborate the philosophical content of two of the 18 questions, namely on the existence of void and the plurality of worlds. Since this has previously only been done in a superficial way, this paper aims to draw attention to al-Bīrūnī’s hitherto unknown philosophical doctrines. In the course of this investigation, it will be necessary to consider his arguments from the letters in view of the background of the ancient, Neoplatonic, and Arabic philosophical and theological discourse. Since this letter exchange is dated to the beginning of Avicenna’s career, his answers illuminate the development of his thought.