A shaman is a man or woman with a special calling to live in two realities at once— the ordinary world we all know well and a deeper, higher reality, both transcendent and profoundly interior, where everything has a spiritual meaning. The shaman sometimes carries a ladder to symbolize the comings and goings between these worlds, and the drum, one of the tools of his trade, may have markings that show the two worlds within a single circle. With his visionary ability to see the spiritual nature of an illness and perceive deep stories hidden within events, a shaman heals and advises his people.
A shaman is schooled in entering strange in-between worlds of imagination. He is a healer and a teacher, a guide of souls. He speaks as though this ordinary world has a richer, hidden dimension. Through music, trance, and prayer he finds his way into areas of inner space that most people are never aware of. He may call this deep interiority the otherworld or the land of the ancestors. He could call it the kingdom of heaven.
The shaman speaks in poetic language, the only way to describe what he sees on the other plane. He may use metaphor, parable, image, story, song, dance, masks, costumes, and props. He leads rituals, heals spiritually, and serves as the messenger to his community from the otherworld. — Thomas Moore, Writing in the Sand
Links to articles on Beyond Meds that look at the Shamanic-like nature of consciousness