As a proud and passionate advocate and writer he spoke and wrote about a vast range of subjects, including plant-based entheogens, psychedelics, shamanism, alchemy, metaphysics, language, philosophy, culture, technology, environmentalism, as well as the theoretical origins of human consciousness.

Was often referred to as “the Timothy Leary of the 90’s.” In fact, Terence McKenna, who so playfully and persistently pressed his message that psychedelics are mankind’s salvation, was christened by Timothy Leary himself as “the Timothy Leary of the 90’s.”

**Sidenote: Timothy Francis Leary (October 22, 1920 – May 31, 1996) was an American psychologist and writer well known for his strong advocacy of psychedelic drugs. Evaluations of Leary are polarized, ranging from bold oracle to publicity hound. He was “a hero of American consciousness”, according to Allen Ginsberg, and Tom Robbins called him a “brave neuronaut”.

In addition to being known as the “the Timothy Leary of the 90’s”, Terence McKenna was called “one of the leading authorities on the ontological foundations of shamanism”. Ontology is essentially the branch of philosophy that studies concepts such as existence, becoming, being, and reality. He was also referred to as the “intellectual voice of rave culture”.

Terence McKenna’s History & Early Influences
Terence McKenna’s initial interest in the world of psychedelics and naturally occurring psychedelic substances was sparked in the early 1960s. His interest in psychedelics is said to have been ignited after he read several books including Aldous Huxley’s ‘The Doors of Perception’ and Heaven and Hell.

In 1965, McKenna enrolled in the University of California, Berkeley where he began studying Art History. Despite pursuing Art History as his main field of study upon his initial enrolment, McKenna graduated with a bachelor’s degree in ecology, shamanism, and conservation of natural resources in 1975 from the same institution (University of California, Berkeley). The years spanning his formal education, from 1965 to 1972 when he returned to U.C. Berkeley to finish his studies, were filled with plenty of travel, exploration, immersive and life-altering experiences, and profound journeys of discovery which would ultimately shape the course of his life entirely.

In 1967 is when he decided to truly explore his intrigue and interest in shamanism and immerse himself in the practice and everything surrounding it. As a result, he began studying shamanism through the study of Tibetan folk religion. It was also in 1967, which is the year he personally referred to as his “opium and kabbala phase”, when he travelled to Jerusalem, where he met Kathleen Harrison, an ethnobotanist, who would later become his wife.

In 1969, McKenna traveled to Nepal as he continued on his immersive journey of profound discovery led by his interest in hallucinogenic shamanism and Tibetan paintings, to learn first-hand about the shamanic use of psychedelic plants. In Nepal, he sought out shamans of the Tibetan Bon tradition, with the intention to learn more about the shamanic use of visionary plants and gain a greater degree of wisdom and understanding of this sacred practice. Bon is considered to be the indigenous religious tradition of Tibet, a system of shamanistic and animistic practices performed by priests called shen (gshen) or bonpo (bon po).

During his time spent in Nepal, McKenna studied the Tibetan language and also became a hashish smuggler. Hashish, also known as hash, is essentially a drug made by compressing and processing trichomes of the cannabis plant. He continued to work as a hashish smuggler until one of his shipments was seized by US Customs. Needing to move on, McKenna went to southeast Asia where he spent time wandering and exploring his new surroundings, toured the old ruins, and even became a professional butterfly collector in Indonesia.

Terence McKenna’s Life-Changing Travels to South America
In 1970, McKenna, his brother Dennis, and three of their friends embarked on the ultimate journey and traveled to the Amazon forest in Columbia, South America. Their initial quest was to find oo-koo-hé, a plant preparation made by the native people containing dimethyltryptamine (DMT). However, during their search for oo-koo-hé, they came across openings in the forest where they found fields full of gigantic Psilocybe cubensis mushrooms. This discovery changed everything and became the new focus of their entire expedition.

After spending some time in the Colombian Amazon forest, Terence and his brother invested a great deal of time and energy into learning everything they needed to know about the specific cultivation techniques used by the farmers in the region. They then brought the Psilocybe cubensis mushroom spores back with them to the United States.

Using all the experience and knowledge they gained, the Psilocybe cubensis spores, and ordinary kitchen utensils and implements, McKenna and Dennis developed a cultivation technique that essentially anyone could follow if they were eager to cultivate and grow their own mushrooms. This was a profound moment of ‘achievement’ and vital step in the psychedelic community as up until that point, no one had figured out how to do it. This also marked the very first time ‘laypeople’ could essentially produce entheogens in their own homes.

Terence McKenna’s remarkable efforts ultimately culminated in their groundbreaking book titled ‘Psilocybin: Magic Mushroom Grower’s Guide’ which was officially published in 1976, authored under the names O.T. Oss and O.N. Oeric. In 1975, the year prior to the highly successful release of ‘Psilocybin: Magic Mushroom Grower’s Guide’, Terence and Dennis published another landmark book titled ‘The Invisible Landscape: Mind, Hallucinogens, and the I Ching’, which was greatly inspired by their life-altering trip to the Amazon. The brothers’ incredible expeditions, adventures and discoveries and profound experiences in the Amazon would later become the main inspiration and focus of another one of Terence Mckenna’s books titled ‘True Hallucinations’, which was published in 1993.

In the early 1980s, McKenna began to speak publicly on the topic of psychedelics, establishing himself as one of the pioneers of the psychedelic movement. His main focus was on plant-based psychedelics such as psilocybin mushrooms, which were essentially the catalyst for his career, ayahuasca, cannabis, and the plant derivative DMT. He conducted workshops and lecture tours promoting natural psychedelics as a way to explore universal mysteries, re-establish a harmonious relationship with nature, and stimulate the imagination.

McKenna also began lecturing locally around Berkeley as well as started appearing on some underground radio stations. In fact, Hundreds of hours of McKenna’s public lectures were recorded either professionally or bootlegged and have been produced on cassette tape, CD and MP3.
McKenna became a fixture of popular counterculture as well as a popular personality in the psychedelic rave/dance scene of the early 1990s with frequent spoken word performances at raves.

He also made several contributions to psychedelic and goa trance albums by The Shamen, Alien Project, Capsula, Entheogenic, Spacetime Continuum, Zuvuya, Shpongle, and Shakti Twins.
In 1985, Terence McKenna along with his wife Kathleen founded Botanical Dimensions – Another one of their great achievements. Botanical Dimensions, a non-profit preserve on Hawaii’s Big Island, was dedicated to collecting, protecting, and propagating plants with ethnomedical significance.

They also focused on educating others about plants and mushrooms that they felt to be significant to cultural integrity and spiritual well-being. A big part of the preserve’s work included continuously updating and maintaining an accurate database on all the supposed healing properties of the plants.

Terence McKenna’s ‘The Stoned Ape Hypothesis’
Terence McKenna’s revolutionary literary accomplishments certainly did not end there. Another incredibly influential and important book McKenna wrote was his 1992 ‘Food of the Gods: The Search for the Original Tree of Knowledge A Radical History of Plants, Drugs, and Human Evolution’. It is in this very book that he explains his “Stoned Ape Hypothesis.” McKenna’s “Stoned Ape Hypothesis” is based on his belief that Psilocybe cubensis contributed to the increase in brain size and enhanced capabilities of all our early human ancestors, ultimately leading to the evolution of Homo Sapiens.

McKenna goes on to explain that as Africa began to undergo desertification, human ancestors were forced out into the savannas and out of the forests to find food. In order to survive and provide for themselves and their families and elders, these groups of people would follow footprints and dung on the ground to find animals to hunt and eat. As it so happens, the hallucinogenic magic mushroom Psilocybe cubensis is a thriving dung-lover and was therefore frequently found growing in the manure of the animals that lived in the savanna.

According to Terence Mckenna’s “Stoned Ape Hypothesis” (as well as based on the above findings), it is believed that our human ancestors ate these magic mushrooms and experienced their extraordinary hallucinogenic effects. While magic mushrooms can bring about a vast range of profound hallucinogenic effects, the effects experienced by these individuals were described as “mind-opening,” enhanced feelings of empathy, increased courage, and seeing fractal patterns even with their eyes closed.

After consuming the hallucinogenic magic mushrooms Psilocybe cubensis, it is said that leaders began to emerge within these groups as those who were brave and kind to others. These leaders essentially became a trusted source of strength and guidance to the rest of the members as well as the one’s that would look out for everyone’s best interests.

McKenna’s theory and “Stoned Ape Hypothesis” goes on to propose that psilocybin magic mushrooms improved visual acuity in individuals, essentially making them better and more skilled hunters. He went on to state that more food meant a higher rate of reproductive success. Additionally, McKenna suggested that higher doses of Psilocybe cubensis would increase activity in the language-forming regions of the brain. Further, McKenna said the effects of psilocybin dissolved the ego and contributed to the development of religion.

So, in essence, Terence McKenna’s theory argues that access to hallucinogenic magic mushrooms was to all intents and purposes an evolutionary advantage for humans. In fact, McKenna went as far as to call it an ‘evolutionary catalyst.’

Terence McKenna’s belief in naturally occurring psychedelic substances
Throughout all of Terence McKenna’s travels, achievements, literary accomplishments, immersive experiences, journeys of discovery, and strides in the psychedelic world, he continuously advocated for the exploration of altered states of mind via the ingestion of naturally occurring psychedelic substances, particularly experiences facilitated by the ingestion of high doses of psychedelic mushrooms, ayahuasca, and DMT.

He believed these three powerful psychedelics to be the apotheosis of the psychedelic experience. He was significantly less enthralled with synthetic drugs, stating that, “I think drugs should come from the natural world and be use-tested by shamanically orientated cultures. One cannot predict the long-term effects of a drug produced in a laboratory.”

Besides being one of the most influential advocates for the exploration of altered states of mind via the ingestion of naturally occurring psychedelics, McKenna always stressed the responsible use of psychedelic plants, saying: “Experimenters should be very careful. One must build up to the experience. These are bizarre dimensions of extraordinary power and beauty.

There is no set rule to avoid being overwhelmed, but move carefully, reflect a great deal, and always try to map experiences back onto the history of the race and the philosophical and religious accomplishments of the species. All the compounds are potentially dangerous, and all compounds, at sufficient doses or repeated over time, involve risks. The library is the first place to go when looking into taking a new compound.”

In addition, McKenna also recommended, and often spoke of taking, what he called “heroic doses”. He defined a heroic dose as five grams of dried psilocybin mushrooms, taken alone, on an empty stomach, in silent darkness, and with your eyes closed. He believed that when psilocybin mushrooms were taken in this particular way one could expect a profound visionary experience, believing it is only when “slain” by the power of the mushroom that the message becomes clear.

Although McKenna avoided giving his allegiance to any one interpretation (this formed part of his rejection of monotheism), he was open to the idea of psychedelics as being “trans-dimensional travel”. As part of that view, he proposed that DMT sent one to a “parallel dimension” and that psychedelics enabled an individual to encounter “higher dimensional entities”, or what could be ancestors, or spirits of the Earth.

McKenna supported this by saying that if you can trust your own perceptions it appears that you are entering an “ecology of souls”. McKenna also put forward the idea that psychedelics were “doorways into the Gaian mind”, suggesting that “the planet has a kind of intelligence, it can actually open a channel of communication with an individual human being” and that the psychedelic plants were the facilitators of this communication.