Many of Copeau's students and colleagues in the first half of the twentieth century used a specific vocabulary to describe successful performance. The performer was ‘in a trance’, or ‘possessed’, or in an ‘altered state of being’. Decroux spoke of ‘evicting the tenant from the apartment so that God could come to live there’. For Copeau and others, the mask was an important tool in the discovery of this optimum state. In this article, Thomas Leabhart suggests that the ideas of the American theatre theoretician David Cole might help us to explore what this language means in terms of shamanic voyages. Thomas Leabhart is Resident Artist and Professor of Theatre at Pomona College in California, editor of Mime Journal, and author of Modern and Post-Modern Mime (Macmillan, 1999). He is also a member of the artistic staff of the International School of Theatre Anthropology (ISTA) and teaches workshops and performs internationally. Leabhart studied with Etienne Decroux from 1968 to 1972, and served as his teaching assistant and translator.