Nothing can temper the spirit of a warrior as much as the challenge of dealing with impossible people in positions of power. Only under those conditions can warriors acquire the sobriety and serenity to withstand the pressure of the unknowable.

In Carlos Castaneda e a Fenda entre os Mundos - Vislumbres da Filosofia Ānahuacah no Século XXI Brazilian writer Luis Carlos de Morais analyzes the work of Carlos Castaneda its cultural implications and its continuation in other authors. ISBN 0-06-019220-8. In his books Castañeda narrates in first person the events leading to and following after his meeting Matus a half-Yaqui "Man of Knowledge" in 1960.

Starting with The Teachings of Don Juan in 1968 Castaneda wrote a series of books that describe his alleged training in shamanism. The books narrated in the first person relate his supposed experiences under the tutelage of a Yaqui "Man of Knowledge" named Don Juan Matus.