Engaging Zen Skeptically

I've a ongoing interest in Zen Buddhism, driven largely by the fact that I occasionally brush up against its edges in the course of my ongoing martial arts training. So I've been reading Zen and the Brain by James Austin with great interest. It takes a subject which has been the source of much bad modern writing and treats it in an intelligent and non-sensational fashion.

But I'm finding it difficult to reconcile Dr. Austin's views of the roots of Zen experiences with his approbation for the practice as a whole. The thesis of the book is that Zen experiences are a natural phenomena arising from within the brain; Dr. Austin explicitly discounts any sort of supernatural source. And yet, at the same time, he is very positive about the transcendent episodes that he refers to as "absorbtions".

The question keeps arising time and again is "How is Zen anything other than self delusion?". The absorbtions discussed in the book, especially the "ultimate" experiences of kensho/satori, are described in terms centering around the dissolution of the self/other boundary and the fundamental unity of all things. But these descriptions border on the supernatural, which Dr. Austin has explicitly rejected.

Dr. Austin refers to the illusory nature of the self/other boundary. But, if you accept that the world is real (as opposed to belief in Maya), as Dr. Austin seems to do, then aren't you also required to accept the actuality of the self/other boundary? "Self" and "other" are real categories; if I cut you, I will not bleed nor feel the pain, but you will. Granted, "self" and "other" can be blurred in a psychological sense; I may empathize with your pain when you are cut. However, you are still the one who is feeling the primary pain of injury.

In the same vein, it seems that the enlightenment of kensho is also incompatible with belief in a mundane material world. The feeling of the unity of all things has no material foundation; we're most distinctly not connected with the Universe in any "deep" sense of the word. We may be interconnected and interdependent, in an ecological and social sense, but there is no support to be found in the material world for some sort of transcendental, universal unity among all things.

This is what I mean when I ask whether Zen is just self-delusion. Zen practice does seem to have a salutory effect on people, but this salutory effect is based on ideas which are impossible to support without invoking supernatural phenomena of some kind. I actually came to this realization while I was reading Dr. Austin's description of "The Miracle of Marsh Chapel" (chap. 102 in my edition). After reading his description of the effects of psilocybin exposure on attendees at a religious service my first reaction was not "wow, the psilocybin really helped them deepen their religious experience" but rather "so the psilocybin made them more suggestible, big deal".

I guess my question comes down to this: Dr. Austin seems to reject the supernatural, so how can he endorse any practice which encourages belief in non-naturalistic phenomenon? I'm not prepared to accuse Dr. Austin of hypocrisy, since the apparent contradiction could quite easily be the result of ignorance on my part. But on the face of it Dr. Austin's position seems to be untenable.