"The 20th century mind is nostalgic for the paradise that once existed on the mushroom-dotted plains of Africa, where the plant-human symbiosis occurred that pulled us out of the animal body and into the tool-using, culture-making, imagination-exploring creature that we are. And why does this matter? It matters because it chose that the way out is back, and that the future is a forward escape into the past. This is what the psychedelic experience means."

"And this is where the psychedelic shaman comes in. Because I believe that what we really contact through psychedelics is a kind of hyperspace, and from that hyperspace, we look down on both the past and the future and we anticipate the end."

I think Terrance suggests the idea of reverse time even better in a talk used on the song "Re: Evolution" by the group "The Shamen" on their album "Boss Drum" :

"Human history represents such a radical break with the natural systems of biological organization that preceded it, that it must be the response to a kind of attractor, or dwell point that lies ahead in the temporal dimension. Persistently Western religions have integrated into their theologies the notion of a kind of end of the world, and I think that a lot of psychedelic experimentation sort of confirms this intuition, I mean, it isn't going to happen according to any of the scenarios of orthodox religion, but the basic intuition, that the universe seeks closure in a kind of omega point of transcendance, is confirmed, it's almost as though this object in hyperspace, glittering in hyperspace, throws off reflections of itself, which actually ricochet into the past, illuminating this mystic, inspiring that saint or visionary, and that out of these fragmentary glimpses of eternity we can build a kind of map, of not only the past of the universe, and the evolutionary egression into novelty, but a kind of map of the future, this is what shamanism is always been about, a shaman is someone who has been to the end, it's someone who knows how the world really works, and knowing how the world really works means to have risen outside, above, beyond the dimensions of ordinary space, time, and casuistry, and actually seen the wiring under the board..."