The ontological turn in anthropology renews the questioning of otherness by being attentive to the diversity of conceptions of the world and phenomenological relations to the world. Descola’s model has become an essential part of this theoretical movement. It distinguishes three ontologies other than the one currently dominant in the West. While he admits the possibility of their expression in the ordinary lives of Westerners, it is only in a fleeting mode. Drawing on the model of cognitive polyphasia, extended here to ontologies, and using alternative and complementary medicine as its ethnographic terrain, this research shows that these other ontologies can profoundly organize experiences. Consumers can inhabit worlds other than the dominant one. They may inhabit several worlds (e.g. animist and naturalist) hybridizing them or not. They may draw highly variable boundaries between humans and nonhumans (both interpersonal and intrapersonal). Various theoretical and operational implications for marketing are outlined.