Godefroid de Callataÿ is Professor of Arabic and Islamic Studies at the Oriental Institute of the University of Louvain. He specializes in the history of Arabic sciences and philosophy, and the role played by Islam in the transmission of Hellenic knowledge to the Latin West during the Middle Ages. Amongst other subjects, he has published extensively on the Rasa'il Ikhwan al-Safa', and has already contributed to the present series by editing and translating Epistle 36, and, together with Bruno Halflants, the short version of the epistle on magic (52a). Since 2012, he is also the director of Speculum Arabicum, a project on comparative medieval encyclopaedism at the University of Louvain.