A trailblazing anthropologist and an indigenous Amazonian healer explore the convergence of science and shamanism“The dose makes the poison,” says an old adage, reminding us that substances have the potential to heal or to harm, depending on their use. Although Western medicine treats tobacco as a harmful addictive drug, it is considered medicinal by indigenous people of the Amazon rainforest. In its unadulterated form, it holds a central place in their repertoire of traditio