Christian Rätsch is an author, an anthropologist and Germany's leading expert on ethnopharmacology. He lived for three years with the Lacandón Indians in Chiapas, Mexico and did his doctoral thesis on their spells and incantations. Rätsch works in Hamburg, Germany, as a freelance author and lecturer and conducts research into the ethnopharmacology of psychoactive plants and animals. He has published a number of books on these topics, both in German and in English, and is the founder and co-editor of The Yearbook of Ethnomedicine and the Study of Consciousness.