Ph. D. (1991) in Islamic Studies, The Hebrew University of Jerusalem. He has published on Imami Shi'i and Isma'ili doctrine and exegesis and on the Nusayri-Alawi religion. His studies include Scripture and Exegesis in Early Shi'ism  (Leiden and Jerusalem 1999) and (in collaboration with Aryeh Kofsky) The Nusayri-Alawi Religion: An Enquiry into its Theology and Doctrine, Leiden 2002.