Khaled El-Rouayheb is a Professor of Islamic Intellectual History in the Department of Near Eastern Languages and Civilizations at Harvard University, Massachusetts. He specializes in Arabic and Islamic intellectual history, especially in the period from the thirteenth to the eighteenth centuries. He is the author of Before Homosexuality in the Arab-Islamic World, 1500 1800 (2005) and Relational Syllogisms and the History of Arabic Logic, 900 1900 (2010). He is also co-editor of the forthcoming Oxford Handbook of Islamic Philosophy.