The History of Shamanism
The term "shaman" is believed to have originated among the Siberian Tungus (Evenks) and the literal translation of shaman is "he (or she) who knows".
In some theosophical circles it's also believed that the words Shaman may have derived from Sanskrit through the confusion of the words shamanism and shramanism. There is a strong shamanistic influence Bon on central Asian and Tibetan Buddhism which also uses Sanskrit, so perhaps there is an overlap from popular etymology, if not a direct linguistic influence.
Buddhism and Shamanism
Buddhism became popular with shamanic peoples such as the Tibetans, Mongols and Manchu after the fourteenth century. Forms of shamanistic ritual combined with Tibetan Buddhism became institutionalized as state religion under the Chinese Yuan dynasty and Qing dynasty.
Shamanistic practices are thought to predate all organized religions, and certainly was practiced in the neolithic. Aspects of it are encountered in later, organized religions, generally in their mystic and symbolic practices.
Paganism and Shamanism
Greek paganism was influenced by Shamanism, reflected in the stories of Tantalus, Prometheus, Medea, Calypso and many others, as well as in the Eleusinian Mysteries (and other mysteries).
Christianity and Shamanism
There are also similarities between Christianity and Shamanism. One such comparison includes the transsubstantiation of bread and wine in the Catholic religion. This can be seen as a shamanic relic, suggestive of the use of entheogenic (psychedelic) substances to attain spiritual realization.
The Term "Medicine Man"
Note: For more on the subject, see section Native American Shamanism.
Medicine man is an English term used to describe Native American religious figures; such individuals are analogous to shamans. The term "medicine man" has been criticized by Native Americans and various scholars alike.
The primary function of these "medicine men" (who are not always male) is to secure the help of the spirit world, including the Great Spirit (Wakan Tanka in the language of the Lakota Sioux), for the benefit of the community.
Sometimes the help sought can be for the sake of healing disease, sometimes it can be for the sake of healing the psyche, sometimes the goal is to promote harmony between human groups or between humans and nature. So the term "medicine man" is not entirely inappropriate, but it greatly oversimplifies and also skews the depiction of the people whose role in society complements that of the chief. These people are not the Native American equivalent of the Chinese "barefoot doctors", herbalists, or of the emergency medical technicians who ride our rescue vehicles.
Recognition as a Shaman / Medicine Man
To be recognized as the one who performs this function of bridging between the natural world and the spiritual world for the benefit of the community, an individual must be validated in his role by that community.
One of the best sources of information on this subject is the story of a Lakota (Sioux) wicasa wakan ("medicine man") recorded in a book produced with his cooperation called Lame Deer, Seeker of Visions, by John Fire Lame Deer.
On a broader scale, Mircea Eliade's Shamanism puts the whole area of religious experience and practice into a broad historical and ethnographic context.
For more information about Native American Culture see Wikipedia's section on Native American Culture
Parts of the above article licensed under the GNU Free Documentation License. It uses material from Wikipedia. Images courtesy FCIT