[Druidry.org]: Michael Harner describes a shaman this way: "A shaman is a man or woman who enters an altered state of consciousness - at will- to contact or utilize an ordinarily hidden reality in order to acquire knowledge, power, and to help other persons. The shaman has at least one, and usually more, "spirits" in his personal service."
Harner goes on to say, "To this I would add that, in his trance, he commonly works to restore a patient by restoring beneficial or vital power, or by extracting harmful power. The journey to which Eliade refers is usually undertaken to restore power or a lost soul."(2.)
It should be pointed out here that Michael Harner is talking primarily about healing shamanism. A case can be made for the existence of other forms of shamanism, such as warrior shamanism, hunting shamanism, or even evil or black shamanism. In actual practice though, the various forms often exist side by side, though shamans do typically specialize. Thus a healer is not ususally a warrior, etc.
Shamanism, in a "pure" sense, is usually characterisitic of
paleolithic hunter-gatherer societies. As such, it can safely be said to
represent humankind's earliest and most primal form of religion, magic
and healing modality. It is also the most conservative and well
established form of human spirituality, as we were hunter gatherers for
literally thousands and thousands of years, far longer than the
subsequent span of our collective history.
Contemporary thinkers like
ecologist Paul Shephard and anthropologist Calvin Martin maintain that
we are still, essentially, hunter-gatherers who have never left the
Pleistocene era.(3.) This fits in well with many indigenous peoples'
concept of the Original Instructions or Original Teachings, the primary
and aboriginal rules for living received many thousands of years ago
during the dreamtime or mythic beginning time of the tribe.
The Celts were, nonetheless, advanced beyond the paleolithic,
hunter-gatherer stage long before they became distinguishable from their
Indo European cousins and arose as a separate cultural entity. However,
given the notable conservatism of Celtic society, it is very likely
that they preserved archaic elements and institutions long beyond other
Northern and Western European peoples....read more>>>...