- My primary area of research is Chinese religious Daoism and popular religious practice. My early work centered on the growth of deity cults in medieval China and their synthesis with Daoism in the Song. In this connection, I explored the role of blood sacrifice in traditional Chinese religion and the significance of its rejection by the institutionalized religions of Buddhism and Daoism. More recently, I have concentrated on the foundational period of the Daoist church, trying to understand the social and material reality behind surviving texts from this period. _Great Perfection_ explored a Daoist kingdom established during the fourth century. Celestial Masters: History and Ritual in Early Daoist Communities (Harvard East Asia Institute, 2016) is the first history in any Western language of the foundational period of the Daoist religion. Current research interests include the interaction of Daoism with Chinese medical traditions and the Daoism of the Yao minority of South China.