> But if you must, start with something like Prometheus Rising by Robert Anton Wilson. Don't just pull out the Goetia and start summoning demons. Reality may or may not be mutable, but our perception of it certainly is. Would you really pick that as a first experiment?

Maybe so, because my mind is so bull-headedly resistant to being modified (at least in the ways associated with occult stuff, like visions, extreme emotion, etc.) that maybe I need a dose of the hard stuff to even notice it ;)

As a naturalist I don't think I can sign on to the first half, even as a realistic possibility. But for psychological effects, sure, I could buy it. The ability of the mind to do get into pretty extreme psychological states, via ritual and otherwise, is easily underestimated.

In fact I would say many naturalists hold onto that argument harder than just about anyone, because it's critical to help explain the weird stuff people experience (e.g. alien abductions are often hypnagogic hallucinations or sleep paralysis, near-death experiences are due to various impaired brain states, etc.)