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So I have read a ton of books on his life and other things that may have influenced his actions. It seems very likely (although not proven) that he took some sort of hallucinogen before he had his prophetic visions.
The most likely plant that he ingested was this one:
http://en.wikipedia.org/wiki/Datura
Funny enough this very plant grows wild in my backyard right next to my pumpkin patch. So NS, do I eat the plant and create my own religion?