Terence McKenna (1946 – 2000) was an Irish-American researcher, philosopher, speaker, spiritual teacher and writer on many subjects; such as human consciousness, psychedelic drugs, the evolution of civilizations, the origin and the end of the universe, cybernetics, alchemy, and extraterrestrial beings.
Perhaps the most intriguing of Terence McKenna’s fascinating theories and observations is his explanation for the origin of the human mind and human culture.
To summarize: McKenna theorizes that as the North African jungles receded toward the end of the most recent ice age, giving way to grasslands, a branch of our tree-dwelling primate ancestors left the branches and took up a life out in the open — following around herds of ungulates, nibbling what they could along the way.
Among the new items in their diet were psilocybin-containing mushrooms growing in the dung of these ungulate herds. The changes caused by the introduction of this drug to the primate diet were many — McKenna theorizes, for instance, that synesthesia (the blurring of boundaries between the senses) caused by psilocybin led to the development of spoken language: the ability to form pictures in another person’s mind through the use of vocal sounds.