Rüdiger Arnzen’s main areas of research are medieval and early modern Arabic and Persian philosophy and history of the sciences in the Islamic world. Trained in philosophy and Arabic and Persian languages and literatures at the University of Bochum, he participated for many years in the longterm project to compile a Greek and Arabic Lexicon (GALex, organized and edited by Gerhard Endress in cooperation with Dimitri Gutas). He is currently at work on two monographs on medieval Arabic concepts of Metaphysics and on Platonic Forms (ṣuwar aflāṭūniyya) in Arabic philosophy.