Carl Sagan, Cannabis, and the Right Brain Hemisphere, Part I

Carl Sagan In 1971, Harvard Prof. Lester Grinspoon published his milestone book „Marijuana Reconsidered“, in which he featured an essay “Mr. X” by his best friend, the famous astronomer and science popularizer Carl Sagan. In his essay, Sagan reports that for him, the marijuana high led to various cognitive enhancements, including an enhancement of cognitive abilities like enhanced episodic memory, pattern recognition, creativity, and the ability to produce insights. Sagan’s essay “Mr. X” is still one of the most illuminating accounts on the positive mind-altering potential of the marijuana high.


What it comes down to is that modern society discriminates against the right hemisphere.

Roger Wolcott Sperry (1913-1994), neuropsychologist and neurobiologist, known for his revolutionary studies of split brain patients

Carl Sagan, Cannabis, and the Right Brain Hemisphere, Part I

In 1971, Harvard Prof. Lester Grinspoon published his milestone book „Marijuana Reconsidered“, in which he featured an essay “Mr. X” by his best friend, the famous astronomer and science popularizer Carl Sagan. [1]  In his essay, Sagan reports that for him, the marijuana high led to various cognitive enhancements, including an enhancement of cognitive abilities like enhanced episodic memory, pattern recognition, creativity, and the ability to produce insights. Sagan’s essay “Mr. X” is still one of the most illuminating accounts on the positive mind-altering potential of the marijuana high.

I have extensively examined the phenomenon of insights and other cognitive enhancements during a marijuana high from a modern neurophilosophical perspective and think that Sagan’s observations are accurate and groundbreaking. Many other cannabis users before and after Sagan have described similar mind enhancements during a high. My own experiences with the marijuana high had been very similar, and my research aims to explain how marijuana can induce insights and many other cognitive enhancements, given that good quality cannabis is used by skilled users.[2]

Sagan’s Hypothesis

Carl Sagan, American astronomer and popularizer of science (1934-96)
Carl Sagan, American astronomer and popularizer of science (1934-96)

Sagan was so excited about the cognitive enhancements he experienced with marijuana that he used it a lot to come to insights for his work. His biographer Keay Davidson wrote that when Grinspoon received unusual high-quality marijuana from an admirer by mail, he shared the joints with Sagan and his wife Ann Druyan. “Afterward, Sagan said, ‘Lester, I know you have only got one left, but could I have it? I’ve got serious work to do tomorrow and I could really use it.”[3]

Sagan was famous – or, for many of his academic colleagues, infamous – for making brilliant but daring speculations – not only in his field of astronomy, but also in other scientific fields. As his biographer Keay Davidson remarks, Sagan for instance wrongly predicted the existence of complex organic molecules on the moon; but, Davidson adds, “(a)s it turned out later, complex organic molecules pervade much of the outer solar system and beyond.”[4]

In his Pulitzer price-winning book “The Dragons of Eden – Speculations on the Evolution of Human Intelligence”(1977), Sagan introduced a survey of what  cognitive and evolutionary scientists had to say about the evolution of the human mind and presented many of his own brilliant speculative ideas on the nature and evolution of human intelligence. Sagan also introduced a speculative thesis about the effects of marijuana on the human brain. He started from an analogy made by psychologist Robert Ornstein:

“He {Ornstein} suggests that our awareness of right hemisphere function is a little like our ability to see stars in the daytime. The sun is so bright that the stars are invisible, despite the fact that they are just as present as they are in the daytime as at night. When the sun sets, we are able to perceive the stars. In the same way, the brilliance of our most recent evolutionary accretion, the verbal abilities of the left hemisphere, obscures our awareness of the functions of the intuitive right hemisphere, which in our ancestor must have been the principal means of perceiving the world.”[5]

In a now famous footnote to this paragraph Sagan formulates his hypothesis on how a marijuana high could affect thinking:

“Marijuana is often described as improving our appreciation of and abilities in music, dance, art, pattern and sign recognition and our sensitivity to nonverbal communication. To the best of my knowledge, it is never reported as improving our ability to read and comprehend Ludwig Wittgenstein or Immanuel Kant; to calculate the stresses of bridges; or to compute Laplace transformation. (…) I wonder if, rather than enhancing anything, the cannabinols (the active ingredient in marijuana) simply suppress the left hemisphere and permit the stars to come out. This may also be the objective of the meditative states of many Oriental regions.”[6]

Enhancements and Suppression

Let me distinguish two aspects of Sagan’s hypothesis: First, there is the observation that a marijuana high leads to a style of cognition which cognitive scientists consider to be predominantly based in the right hemisphere. Second, Sagan speculates that a marijuana high might suppress left hemisphere functions and, therefore, lead to what we could call “right hemisphere thinking”. Sagan’s hypothesis was based on his knowledge of what current science had to say about the human brain and the different style of cognition in the left and right brain hemispheres, as well as on his own experiences with marijuana.

Sagan’s Claim Reconsidered

During his lifetime, Sagan did not reveal to the public that he was a user of marijuana. In isolation, Sagan’s footnote about marijuana and its possible effect on the brain hemispheres seems to be a spontaneous speculation out of nowhere. Yet, when reading Sagan’s essay “Mr.X”, it becomes clear that Sagan’s experiential basis for such a claim was actually quite broad. In his essay, he describes in some detail not only the enhancements mentioned in his footnote, but he also mentions other cognitive enhancements, such an enhanced ability to remember past events and to obtain deep insights. Also, like some other users before him, Sagan mentions that during a high, he also experienced enhanced

”perceptions of real people, a vastly enhanced sensitivity to facial expressions, intonations, and a choice of words which sometimes yields a rapport so close it’s as if two people are reading each other’s minds.”[7]

Harvard Prof. emer. (Psychiatry) and marijuana expert Lester Grinspoon
Harvard Prof. emer. (Psychiatry) and marijuana expert Lester Grinspoon

Sagan already knew that all of the cognitive enhancements he had described for a high would concern functions which cognitive science at the time found to be predominantly located in the right brain hemisphere; he had described the research concerning split brain patients and more on the pages preceding his hypothesis in “The Dragons of Eden”.

Sagan did not only know this research and did not only have his own knowledge about cognitive enhancements during a high, but he was also well acquainted with his friend Lester Grinspoon’s research about marijuana as a medicine and about its mind-enhancing potential. As Lester Grinspoon told me in private conversation, Carl Sagan had carefully read and commented upon his manuscript of “Marijuana Reconsidered”, in which Grinspoon extensively featured reports of other marijuana or hashish users who had described similar mind enhancements.

Now, what can we say about Sagan’s hypothesis almost 40 years later, with all the progress in the mind sciences on the nature of cognition in the respective brain hemispheres and with our knowledge about the endocannabinoid system and its many functions in cognition?  Was Sagan on the right track?

Read more in part II.

[1] Carl Sagan, „Mr. X“, in: Lester Grinspoon (1971), „Marijuana Reconsidered“, Harvard University Press, Cambridge, Massachussetts, p. 123 – 130. Sagan’s essay was published anonymously, Grinspoon revealed the identity of his author only years after Sagan’s untimely death.

[2] See Sebastian Marincolo (2010), „High. Insights on Marijuana“, Dogear Publishing Indianapolis, Indiana.

[3] Keay Davidson, (1999), „Carl Sagan. A Life.“, John Wiley & Sons, Inc., New York, p. 214.

[4] Ibid., p. 213.

[5] Carl Sagan (1977) „The Dragons of Eden. Speculations on the Evolution of Human Intelligence“, Random House Publishing Group, New York, p. 177

[6] Ibid.

[7] Carl Sagan, „Mr. X“, in: Lester Grinspoon (1971), „Marijuana Reconsidered“, Harvard University Press, Cambridge, Massachussetts, p. 127.

Comment Section

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Neal Smith

Drs. Sagan and Grinspoon were men before their times. Cannabis does, indeed, open the mind to new ideas while somewhat blocking the ability of the mind to clutter thought with mundane matters.

Taken to its limit, perhaps the lack of Cannabis in the daily regimen of U.S. leaders is why there is such a lack of positive leadership?

12/07/2015

DC Morris

Men of the Earth have known the power of cannabis for centuries. Mr. Hearst made it part of the American Game and his rule was one of the more successful business/social manipulations of modern time. To bad they were never able to completely control, and in effect, set up the Legislation that is now sweeping the People of the States. The right to decide on cannabis is now a national issue. God Speed Free People of the World.

18/09/2015

Jeff Brown

Cannabis is the most useful plant on the planet; food, clothing, shelter, energy, medicine, insight, re-creation. It has been mankinds companion and helpmate since the beginning. Any law against it is a crime against humanity, creation and the Creator.

22/08/2016

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