I think I'd have to go along somewhat with McKenna on this and say that spice is THE psychedelic for skeptics. After all, I know I've definitely met people who don't believe in the psychedelic experience. Unlike some doses of mushrooms or acid, you don't need a large chunk of time and you can't write off your visuals as having a basis in the normally visible world. The fact that you can completely immerse yourself in an alternate reality makes spice the perfect response for someone who tells you these experiences are not "real". Burnt makes some great points and I almost completely agree with him on the implications of how a change in neurotransmitter balances changes your perceptions, however, if the spice has taught me anything it's that we know nothing. I respect and find merit in his view, but it carries a level of reductionism I would expect from a chemist of such high caliber. I think the experience of DMT is too intense, too vivid and too inherently overwhelming and awesome to be considered not real by a skeptic. What can you say when you feel as though you have actually gone somewhere outside of this dimension? Even the most rationalizing and non believing person is subject to that experiential reality of spice which seems to resonate with the human condition across the board.