Acting Associate Professor in the Department of Religious Studies, Stanford University. His recent publications include "The Early History of the Zhouyi cantong qi" Journal of Chinese Religions 30, 2002 and "Early Daoist Meditation and the Origins of Inner Alchemy" in Daoism in History: Essays in Honour of Liu Ts'un-yan, ed. Benjamin Penny (Routledge, 2004). His latest work, Great Clarity: Daoism and Alchemy in Medieval China, will be published by Stanford University Press in 2004. He is the editor of the forthcoming Encyclopedia of Taoism (Routledge) and is currently working on the textual and exegetical tradition of the Zhouyi cantong qi.