I've read Casteneda's books for close on 35 years. I'm certain they are 'fiction', or lets say a tale based on some kind of fact. And I have to state I'm unhappy to see the development of the New Age, with it's wishy washy thinking and it's 'Harry Potter' sensationalism. And of course I'm unhappy to see Casteneda dragged into that bag, because I think association with the New Age stuff debases Casteneda.
I smile at the irony then, of my, if not 'believing' then TRUSTING Carlos Casteneda implicitly. I think he's pretty much on the money. It's a gut feeling. Years ago I found my hands in a dream, just like Casteneda describes, and so I began Lucid Dreaming. This practice has changed me more than any other single event or experience I've had. It's one thing to read this stuff and speculate, another to actually have the experiences pretty much as he describes for oneself. I'm a rational person, I could say he programmed my dreams but the truth is I had similar experiences of non everyday reality from when I was a child and one childhood and pre linguistic memory in particular predicates my trusting him.
I have picked the books up and been skeptical time after time. Not only did I read the damning critiques of Richard de Mille (who's actually rather kind to Carlos)I just struggled with my own doubts as to the validity of what I experienced. Pretty much like Carlos himself!. The trouble with the critiques is that they all treat the works as being flawed because Carlos wasn't in Mexico on the date he says he was blah blah blah, they are concerned with tiny empirical details but they never examine WHAT he says, they never actually look at his or don Juans 'explanations' (I don't feel right calling then his 'metaphysics'). If you are already a lucid dreamer and haven't read this book, then it's worth doing so because you'll recognise the 'landscape'. If you're not already a dreamer then this book may be a threshold for you.
Eitherway, all his books make wonderful reading. Even if you just take them as a story, they are entertaining, well written and insightful in many revealing ways. If on the otherhand you wake up one night looking at your hands, then realise you're in a dream, or if you dream you 'wake up' back in the very same hospital ward coming round from an operation you had back in 1970, only to wonder if the life you thought you had lived from that date on has all been a dream while you were under the anaesthetic, then you realise you live in a Universe that is suddenly larger, richer and more complex than the one you left behind.
Ha ha ha Casteneda has this effect upon you, and I for one am profoundly glad I've stuck with him.