Hallucinogenic drugs have often been supposed to be responsible for many fantastic accounts of miracles and general religious phenomenon, from the Salem witch trials and panic to various sightings of the Virgin Mary. However, not many dare to apply such a theory to one of the head honchos of half the religions in the world, indeed, the man who could be said to be the basis for all modern law.
But Professor Shanon has had enough of this reverence for miracles. In his paper Biblical Entheogens: a Speculative Hypothesis, he details numerous parallels between visions and experiences of Moses and hallucinations experienced under various psychedelics.
Pause and consider that this is not at all a far-fetched theory. Early humans had no concept of mind-altering substances beyond alcohol - to them, if you ate something, it either killed you or it didn't. When some attachment between altered states of consciousness and a previously consumed food did eventually dawn on people, they immediately took it for a connection to spiritualism. Marijuana, ayahuasca, peyote, and the famed "magic mushrooms" have all been connected to spirituality in beliefs such as Shamanism and Rastafari.
In the event depicted as the "theophany", Moses' experience includes thunder and lightning, a pillar of fire, trumpet calls when no instruments are present, the whole mountain smoking and quaking, and a voice booming out of the sky. Anybody who's experimented with doses of LSD or other psychedelics can relate. Note that it's not merely a matter of seeing and hearing hallucinations; one's thoughts and emotions become very confused during such experiences and one's own ideas may become the strangest experiences of all. Feelings of religious awe and emotional epiphanies are frequent and common in the psychedelic experience, even in doses not sufficient to trigger visual and aural hallucinations.
The problem is that the exact drug available in the Jerusalem area at the time that could have caused such an experience is not known. However, even plain old rye bread can become infected with the fungus known as ergot, and there is evidence of cases of ergot poisoning present in nearby Europe. Shanon's theory merely points out similarities between Moses' reports of miracles and the effects of drinking Ayahuasca, and leaves it at that. This drink is prepared from plants of the psychotria genus, which only grow in tropical regions.
This is not to say that such a drug would have to have been imported. There may have been species of another plant with psychedelic effects growing in the Mediterranean region around the 1500s B.C., and simply become extinct by now. One such example that we know of was silphium, a plant used to produce a drug widely thought to have been used for birth control - among many other uses.