I will endeavor to summarize the highly complex and sophisticated system of spiritual training outlined by Don Juan in Tales of Power. The aim of this training is to produce an impeccable warrior - that is, a being who is at all times completely in possession of himself. The warrior is concerned only with expressing the totality of himself, not with praise or support from others. He neither seeks nor admits a master. The warrior's state is achieved with the aid of a teacher and a benefactor. To understand the respective roles of teacher and benefactor, one must consider the concepts of the tonal and the nagual, which are basic to the warrior's path. The tonal is the sum of any individual's perceptions and knowledge, everything he can talk about and explain, including his own physical being.

The nagual is everything outside the tonal: the inexplicable, the unpredictable, the unknown. The nagual is everything that cannot be talked about or explained, but only witnessed. The sudden irruption of the nagual into the tonal can be lethal unless the student is carefully prepared. The teacher's role is to clean up and strengthen the tonal, so that the student is able to deal with the nagual which the benefactor will then demonstrate. The teacher and the benefactor show the student how to reach the unknown, but they cannot predict what will happen when he does reach the nagual. The nagual is by its nature unpredictable, and the whole training is extremely dangerous. While the tonal, the totality of conscious existence, shapes the individual being, the tonal is in turn shaped by the nagual, by everything it is not, which surrounds it like a mold. The tonal tends to shut out and deny the nagual, which takes over completely in the moment of death.

If we see the nagual as the unknown, the unpredictable and unexplainable, the role of the artist is to make contact with the nagual and bring a part of it back into the tonal in paint or words, sculpture, film, or music. The nagual is also the area of so-called psychic phenomena which the Buddhists consider as distractions from the way of enlightenment. Buddhism and the teachings of Don Juan are simply not directed towards the same goals. Don Juan does not offer any final solution or enlightenment. Neither does the artist.

–William S. Burroughs, from CoEvolution Quarterly Spring 77