Medical systems need to be understood from within, as experienced by healers, patients, and others whose minds and hearts have both become involved in this important human undertaking. Exploring how the performance of healing transforms illness to health, initiate to ritual specialist, the authors show that performance does not merely refer to, but actually does something in the world. These essays on the performance of healing in societies ranging from rainforest horticulturalists to dwellers in the American megalopolis will touch readers'' senses as well as their intellects.