The word 'shaman' came into European languages in the seventeenth century. Russian explorers picked it up from the Tungus people of Siberia. The Tungus word 'saman' named a certain kind of person: someone who could drop into a trance on purpose, travel to other levels of reality, and come back with knowledge or healing for the community. Later, anthropologists used the same word for similar people all over the world: the sangoma of southern Africa, the mudang of Korea, the machi of the Mapuche people of Chile, the pajeú of Amazonian Brazil, the angakoq of the Inuit, the völva of Norse tradition, the druid of Celtic Ireland. Their languages, cultures, homelands, and eras were wildly different. Yet they shared a cluster of traits. The Romanian historian of religion Mircea Eliade named those traits in his landmark 1951 book 'Shamanism: Archaic Techniques of Ecstasy.' People have argued over his definition and revised parts of it in the seventy years since, but it is still where any serious study of shamanism begins.
Eliade called shamanism a technique of ecstasy. The word 'ecstasy' comes from the Greek 'ekstasis,' which literally means 'standing outside' yourself. For Eliade, the one thing that defines a shaman is controlled ecstasy: the shaman changes their state of mind on purpose, lets the soul leave the body and travel to other worlds, and comes back on their own, with memory, with information, and able to act on what they found. That sets the shaman apart from three other people. It is not the ordinary person who falls into ecstasy by accident, through psychosis, fever, or injury. It is not the priest, who channels the divine through fixed ritual but takes no personal journey. And it is not the mystic, who seeks union with the divine but does not usually travel out and return for others. The shaman is a technician of the sacred: someone trained, through initiation and practice, to work skillfully and deliberately in the place where ordinary and non-ordinary reality meet.
In culture after culture, you do not choose to become a shaman. It chooses you. The most common way in, according to the research, is not voluntary at all. It arrives as a serious illness, a near-death experience, a mental health crisis, an overwhelming vision, or a run-in with spirits the person never asked for and cannot shake off. Eliade called this the 'shamanic illness.' It is a stretch of physical or mental extremity that acts as the initiation: a death and rebirth that qualifies the person for the role. Among Siberian peoples, this illness could drag on for years and was sometimes truly life-threatening. Among the Tungus, people who refused the call were said to die. Among the Mazatec of Oaxaca, María Sabina, the most documented mushroom curandera of the twentieth century, got her calling at age six, through a vision of the spirit of mushrooms, soon after her father died. Among the !Kung San of the Kalahari, training starts in childhood with group trance dances that expose the whole community to the energy they call n/om, and the ones in whom it 'boils' strongly are marked as future healers.
The training that follows is hard and long. Among the Siberian Evenki, an apprentice studied with a master shaman for up to twelve years. There was a lot to learn: the layout of the upper, middle, and lower worlds; the names and traits of the spirits and power animals in each; how to drum, sing, and dance your way into the journey state; the healing methods of soul retrieval and extraction; and the ethics of a person who works at the edge between worlds. Comparing it to a medical residency is fair. The shaman is a specialist who spends years in supervised, hands-on training to diagnose and treat one kind of illness, one understood to have a spiritual side as well as a physical one. The hospital is the whole cosmos. The patients are the community. The symptoms are not only in the body.