This essay explores several equivocations in the relationship between state healthcare workers and the Pewenche population in southern Chile. In particular, it focuses on radical differences in understanding the body, personhood, sleeping and dreaming. In Alto Bío Bío, Chile, while healthcare workers diagnose their Pewenche patients with ‘sleep disorders’ and prescribe them sleep-inducing psychotropic drugs, some Pewenche persons fear that by preventing them from waking up, the drugs will render them unable to escape a fatal attack by evil spirits. The sleeping pills, therefore, enact understandings of the body, personhood, sleeping and dreaming that are not at all univocal. This enactment generates a controversy- inducing ‘ontological disorder’ based in an ‘uncontrolled equivocation’, as described by the anthropologist Viveiros de Castro, in which interlocutors are not speaking about the same thing, but they are not aware of this. In more general terms, the essay reflects on the application of technologies premised on multicultural ideology (one nature, many cultures) in contexts where alterity is radically manifested and where the limits of the actors’ different conceptions of personhood appear in all their ontological splendor.