Hassan Ansari earned his doctorate at the Ecole Pratique des Hautes Etudes (EPHE) of the Sorbonne, Paris. He is currently a long-term member at the Institute for Advanced Study in Princeton. His publications include Accusations of Unbelief in Islam: A Diachronic Perspective on Takfir (edited with. Camilla Adang, Maribel Fierro, and Sabine Schmidtke; Leiden, 2015), L'imamat et l'Occultation selon l'imamisme: Etude bibliographique et histoire des textes (Leiden 2017), and a critical edition of Ibn al-Malahimi's Tuhfat al-mutakallimin fi l-radd 'ala l-falasifa (Tehran 2008, with Wilferd Madelung). Sabine Schmidtke is professor of Islamic intellectual history in the School of Historical Studies, Institute for Advanced Study in Princeton.