Look at every path closely and deliberately, then ask ourselves this crucial question: Does this path have a heart? If it does, then the path is good. If it doesn't, it is of no use.

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.