Who is Castaneda from The Way of the Shaman and what is their importance?

Carlos Castaneda is a writer who introduces Westerners to shamanism and its principles. Castaneda is most famous for his books on the teachings of Don Juan and for his candid accounts of using hallucinogenic substances to reach altered states of consciousness. His contribution is in making a clear differentiation between ordinary reality and "nonordinary" reality. Acting as a bridge between traditional shamanic traditions and Western thought, he describes aspects of the shamanic journey he experiences, including drug-induced altered states, and experiences that are labeled "hallucinogenic" in ordinary reality but "real" in those altered states.