Hermann Tessenow is a Senior Lecturer at the Institute for the History of Medicine at Munich University. Paul U. Unschuld is Professor and Director of the Horst-Goertz Institute for the Theory, History, and Ethics of Chinese Life Sciences at Charite Universitaetsmedizin Berlin and is the author of "Huang Di Nei Jing Su Wen: Nature, Knowledge, Imagery in an Ancient Chinese Medical Text" (UC Press, 2003).