THE POWER OF SILENCE Further Lessons of Don Juan By Carlos Castaneda Simon & Schuster. 286 pp. $17.95

For nearly 30 years, beginning in 1960 when he was a 25-year-old graduate student in anthropology at UCLA, Carlos Castaneda has been trying to fathom the secrets of the Yaqui mystic and sorcerer don Juan Matus. Through seven books, from "The Teachings of Don Juan" to "The Fire From Within," faithful readers have followed Juan and Carlos through startling phenomena and mystifying verbiage in search of the secret formula that will let them see into people's souls, perform such magic tricks as jumping off mountains unscathed -- and, by the way, conquer death.

Now, with "The Power of Silence," Castaneda's mentor makes explicit what perceptive readers figured out some time ago: The secret is that there is no secret -- at least not any that you could put into a book. "There are no procedures in sorcery," the sorcerer tells his apprentice, who would really like to be systematic about the whole business. "There are no methods, no steps ... It's an effect that happens all by itself." Castaneda, as he readily admits, has trouble catching on -- or even remembering a lot of what he has seen and heard. So 50 pages later, we have don Juan giving him a variation on the message: "There is no witchcraft, no evil, no devil. There is only perception."

"I understood him," Castaneda remarks after this revelation. "But I could not tell exactly what he wanted me to do." In this, he resembles many of his readers who cannot help wondering whether -- and how -- reading a Castaneda book is supposed to change their lives. In "The Power of Silence," the answer is evidently that we might try to expand our perceptions. Behind its rather wandering narratives and clumsily proliferating terminology, this book -- like its seven predecessors -- seems to be mainly about altered states of awareness and how to get there.

After a quarter-century or so of trying, Castaneda has managed to distill the sorcerer's teaching into nine numbered paragraphs. In these, it turns out that each of us is endowed with energy emanations that form "a ball of light the size of the person's body with the arms extended laterally, like a giant luminous egg." One point of intense brilliance on the surface of this egg is called "the point where perception is assembled" or "the assemblage point." It serves as a sort of perceptual function selector; when it moves from its usual location, "it makes possible the perception of an entirely different world -- as objective and factual as the one we normally perceive." Had enough? If not, continue.

The rest of the book, insofar as it is "about" one definable topic, is about how we can control the movement of our assemblage point. Unfortunately, as noted above, there are no procedures, no witchcraft; it is something that just happens, though it is more likely to happen if you have a surplus of energy and someone like don Juan to slap you on the back in just the right way to shock you out of your everyday perceptual treadmill and into "the realm where miracles are commonplace."

You should be able to control the location of your assemblage point if you can get yourself to "The Place of No Pity" and cultivate your "ruthlessness" to the point where you can go through and beyond the "gigantic, dark lake of silent knowledge" that lies within each of us. What Juan means by "ruthlessness" is not wanton cruelty. Rather, "Ruthlessness is the opposite of self-pity or self-importance. Ruthlessness is sobriety." It is the cool objectivity of warriors (metaphysical warriors) who "are incapable of feeling compassion because they no longer feel sorry for themselves. Without the driving force of self-pity, compassion is meaningless."

And this brings us close to what may be the core message of the book: "Self-importance is the force which keeps the assemblage point fixed. When self-importance is curtailed, the energy it requires is no longer expended. That increased energy then serves as the springboard that launches the assemblage point, automatically and without premeditation, into an inconceivable journey."

Escape from or transcendence of the sense of self is, of course, a recurring theme of mystical literature from Buddha to Alan Watts, with Lao-tse, St. Teresa of Avila, St. Bernard of Clairvaux and dozens of others contributing varied flavors and emphases to the discussion of essentially the same points. Like others who have tilled this field, Juan and his disciple encounter a problem that is perhaps most clearly perceived in the special disciplines of Zen Buddhism: The difficulty of the message is rooted in its essential simplicity; any words used to formulate the message automatically distort it. So the guru must try to make his point through all kinds of extreme, often incomprehensible expedients -- physical violence against the disciple, ego-destructive scolding, confusing verbal tricks and play-acting with sudden, abrupt and unexplained changes of character.

The material in Castaneda's books is probably rooted in some sort of objective or hallucinatory experience -- not cynically invented. If he had made it all up, as some observers have suggested, he could surely have produced something more interesting and coherent; something in which he is not seen so constantly as a dimwitted blunderer. Seen in context with other mystical writings, Castaneda's work seems less eccentric and its authenticity seems less dubious; he intersects frequently with the work of men far removed from him in history, geography and apparent orientation. But by the same token, his work becomes less interesting -- simply an exotic variant on fairly well-known themes. It is both colorful and confusing to the extent that it is imperfectly assimilated. The reader looking for similar material in more coherent and useful form might look into the numerous books on Zen or Christian mysticism.

The reviewer writes about music, books, chess and computer software for The Washington Post.