The book became, unwittingly it seems, the first of a trilogy ultimately concerned with what conscious is and does. The second book, This is Your Mind on Plants (2021), extends Pollan’s project to three mind-altering compounds found in plants: opium, caffeine, and mescaline, and the third, A World Appears (2026), is his attempt to discern consciousness itself. Here I cover Pollan’s investigation into consciousness across the three books, the results of which frustrated him and required a reconciliation.

The Trips Begin

In How to Change Your Mind, Pollan gives a brief summary of the bumpy history of psychedelics. He recounts how the intense and well-supported interest in them as therapeutic agents during the 1950s was almost completely snuffed out in the 1960s when “a moral panic about LSD engulfed America, and virtually all psychedelic research and therapy were either halted or driven underground” (p. 185). The panic reached its apogee when counterculture movements and their leaders, among them Timothy Leary of “turn on, tune in, drop out” fame, were seen as threats to mainstream society in general. The few remaining embers, though, reignited in the 1990s and by 2006 serious interest in psychedelics revived and research into clinical use resumed through legal means. Structures were in place allowing psychedelic use for specific purposes, opening the way for Pollan’s investigation.

Pollan arranged three separate “trips,” one each for the psychedelics LSD, psilocybin, and 5-MeO-DMT (i.e., “The Toad”). He carefully chose a tour guide for each one. He came through these sessions with what he interpreted as a dissolution of his ego, which made more room for his consciousness: “I was present to reality but as something other than my self” (p. 264). After these experiences and interviews with many scientists, psychologists, counselors, and users, Pollan constructed an argument about how the altered consciousness states psychedelics produce can offer benefits to individuals who are healthy or sick, and to societies that are stable or fractious, by sending “a life or culture down a new path” (p. 407). He is inspiring, vague, and fantastical at times; he gets more so in his follow-up book, Your Mind on Plants.

There’s No Place Like Home

Pollan expands his investigation of consciousness-altering substances by marrying it with his passion for plants and gardening. Therefore, he need not look further than his kitchen and garden for sources serving his interest at this stage: opium (poppy), caffeine (coffee and tea), and mescaline (San Pedro cacti). He explained his rationale for choosing these three mind-altering agents:

Taken together, these three plant drugs cover much of the spectrum of the human experience of psychoactive substances, from the everyday use of caffeine, the most popular psychoactive drug on the planet; to the ceremonial use of mescaline by Indigenous peoples; to the age-old use of opiates to relieve pain. (p. 4)

Pollan received guidance and supervision for his trials of opium and mescaline. As a self-described “heavy caffeine user,” he withdrew from it by giving up coffee and tea, thinking he could make inferences about caffeine effects through reverse engineering the experience.

While Pollan describes the effects these three agents had on his consciousness, he went further morphing from his role as an investigative journalist into roles of historian and anthropologist. Pollan covers how opium, caffeine, and mescaline altered the consciousness of millions of people through the millennia, and in doing so, says they figure in world history and human development, often in rather breathtaking terms. Opium spurred “the Romantic revolution in poetry” (p. 31). “Caffeine was the perfect drug not only for the age of reason and the Enlightenment but for the rise of capitalism, too” (p. 119). “The sins of slavery and imperialism, in a global system of production…could only have been fueled by caffeine” (p. 138).

While he does not credit mescaline with having contributed to human progress in such grand scales, Pollan speaks of its power in healing the most devastating wounds. But insofar as affecting consciousness, for him, mescaline does “what all psychedelics do—not so much change how we feel inside as imbue the world around us with never-before-appreciated qualities” (p. 217).

Pollan may have imbibed too much caffeine while writing this book judging from some of the conclusions he makes, but it may have fueled his subsequent quest to understand just what consciousness is rather than just what it does to his mind and its impact on world history. What he found on this quest, or more appropriately, what he didn’t find, became the basis for his next book, A World Appears.

Pollan Trips into a Cave

If psychedelics and mind-altering plants can change consciousness, then, as Pollan surmises in describing his objective with A World Appears, “consciousness is, at its core, a material phenomenon…[or there is] at least some credence to the idea” (p. xx). So off he goes on more trips, this time to experts working on finding a discernible form of consciousness, a trip that in the end fails, but still produces some value towards the way we think about artificial intelligence.

Pollan’s trips takes him to four ports of call, or “four different dimensions of consciousness” (p. xxxi). His first stop is “sentience,” which refers to consciousness as where in living beings sensations are perceived and responses to them generated. The next stop is “feelings,” the awareness of biological phenomena, the communication link between the body and the mind, serving homeostasis, for example. “Thought” is Pollan’s third stop, accounting for “the stream of thoughts that all of us experience every waking moment” (p. xxxii). His trip ends at “self,” or the ’I’ that takes in all of our experiences.

Each trip constitutes a chapter comprising what is known about consciousness from a particular dimension. Pollan describes and evaluates them with the help of people involved in their development. Across the four dimensions, he consults or references a wide range of experts including among others: neuroscientists, physicists, biologists, philosophers, psychologists, screenwriters, novelists, poets, and Buddhists. He combs through their theories, constructs, data, analogies, stories, and metaphors. Pollan, nevertheless, comes up empty, and is “abashed to say I know less now than I did when, naively, I set out to unravel the mystery of consciousness” (p. 225). It took several days in a cave at a Buddhist retreat high in the mountains of New Mexico for Pollan to reconcile with this outcome, “to let go into not-knowing.” He wound up accepting consciousness “as less a scientific or philosophical puzzle to be solved and more as a practice…Consciousness is a miracle, truly, and remains the deepest of mysteries” (p. 239).

So be it, but what then are we to make of the artificial intelligence industries’ determined attempts to integrate or discern consciousness in their machines? Pollan might say they will need a miracle.

Citations:
Pollan M. How to Change Your Mind. Penguin Books; 2019. 464 pages
Pollan M. This Is Your Mind on Plants. Penguin Press; 2021. 288 pages
Pollan M. A World Appears: A Journey into Consciousness. Penguin Press; 2026. 320 pages

Links:
My blog post elaborating on Pollan’s How to Change Your Mind is here, and on Your Mind on Plants is here.

Along with cohost, Dan Albrant, here’s a link to our podcast episode in which we focus on: consciousness, spirituality, and mysticism as what is at work in the effects psychedelics produce, and how they may delineate limits to biomedicine (rational or not), that is, how they brighten or blur the line between classic biomedicine and whatever isn’t. 

Edited by Lucy Bruell.
Web Image: Cave Man, Tim Brown, CC BY 3.0 <https://creativecommons.org/licenses/by/3.0>, via Wikimedia Commons

John O’Connor, whom I happened to interview on May 5, explores a similar dynamic unfolding amid today’s psychedelic renaissance—a movement rife with magical thinking that he sees as something of a religious revival—in his delightful and enlightening new book A Short, Strange Trip: An Untold Story of Magic Mushrooms, Madness, and a Search for the Meaning of Life in the Amazon. 

Some Westerners are appropriating sacred plants while divorcing them from the traditions that gave them meaning—“colonizing them in reverse,” as American ethnobotanist Glenn Shepard puts it (p. 211). For example, ayahuasca use, despite widespread belief, may not date back thousands of years. Instead, O’Connor argues that the practice “rarely existed where Indians remained isolated from Western meddling” (p. 222). Its expansion beyond the Río Napo began relatively recently with Jesuit missions in the early 17th century and later accelerated through 19th-century rubber camps along the major river systems of the Amazon Basin. Through Western tourism, ayahuasca has come to be portrayed as “an ancient ritual for slaking our insatiable thirst for Indigenous salvation and/or for increasingly extravagant highs” (p. 223). 

During our meeting, O’Connor told me he does not “think there’s ultimately harm in appropriating a plant if you find it therapeutic, useful, or even life-saving—which a lot of people are reporting these drugs can be.” 

At the same time, he said, “we need to have an honest, good-faith conversation about where these drugs come from, what their actual Indigenous uses are, and what they are.” 

To write the book, which explores humanity’s broader relationship with psychedelics, from ancient religion to modern medicine, O’Connor worked with the Uitoto people to retrace an expedition undertaken some 50 years ago. Into the Colombian rainforest—home to begonias as red as blood and butterflies as wide as hubcaps—ventured scientific researcher Dennis McKenna and his older brother Terence, the visionary whose “tangled beard hung like an oriole’s nest past his chin” (p. xix). Weary of the war on drugs and fueled by utopian fantasies, Terence’s army of psychonauts sought a legendary hallucinogen that would turbocharge their DNA and “hasten a return to our preindustrial and preliterate past” (p. 284). 

In reality, Terence and his disciples did not transform into “eternal hyperdimensional beings” or travel via “flying saucers of the mind… ‘into the plenum of being’” (pp. 94, 30). Nor did they propel “human evolution forward to its next stage” by connecting to “the mind of nature itself” (pp. 284, 11). But they did experience auditory and visual hallucinations that led them, in a manner not unlike schizophrenia, “to adopt a new narrative interpretation of the world” (p. 95). 

Armed with the spore prints they’d brought back from La Chorrera, the McKenna brothers were “among the first, if not the very first, to successfully cultivate magic mushrooms at home, sparking a major leap forward in psychedelic history” (p. 202). In 1976, they published Psilocybin: Magic Mushroom Grower’s Guide; this April, half a century later, President Donald Trump signed an executive order expediting research into the therapeutic benefits of psilocybin and other substances of its ilk. 

O’Connor mentioned that one such mind-altering drug, ibogaine—made from the root of a Central African shrub—has shown promise in treating post-traumatic stress disorder and substance use disorders. 

“That’s great,” he told me, “but it also has a habit of slowing people’s heart rates considerably,” among other life-threatening side effects.  

“People are diving into these treatments as if there are no potential risks,” O’Connor, who teaches journalism at Boston College, added. “They don’t work for everyone—they’re not a magic bullet.” 

The remainder of the interview, which follows, has been edited for length and clarity.  

Why did you choose Terence as the focal point of the book? 

I hadn’t heard of him, and I pride myself on knowing about eccentric, overlooked weirdos from the psychedelic ’60s and ’70s. I was doing a lot of retail therapy online during the pandemic, as were many folks, and I came across his book, True Hallucinations (1989), totally by happenstance. I hadn’t known anything about it, bought it, and put it on the shelf for two years.  

I finally opened it one day and started reading. I had some preconceived ideas without really knowing anything about Terence or his subject. I thought it was probably some hippie-dippy thing about machine elves, and it sort of is that, but that’s not all it is. It’s a great narrative and just fascinating—it just captured me. 

Terence postulated that psilocybin mushrooms “played a crucial role in human evolution, giving our remote ancestors a jolt in language and cognition” and “turning Homo erectus into Homo sapiens.” While there’s nothing in the fossil record to support Terence’s “stoned ape theory,” according to anthropologist Laura Weyrich, advances in proteomics and DNA-sequencing technology could potentially indicate whether ancient hominids at least ate psychedelic mushrooms.  

How plausible do you think stoned ape theory is? 

When I first began looking into it, I was like, “Oh, this is so ridiculous.” I was embarrassed to ask these various paleoanthropologists, archaeologists, and researchers about it. I was like, “Oh my God, I can’t ask this, but I have to.” But it turns out that, as a thought experiment, many of them also found it interesting. It’s not something that I think is ultimately really provable. You could find some tangential scientific evidence, but you’re probably never going to get a smoking gun. 

Terence had a lot of theories—some relatively sane-seeming, like the stoned ape theory, and some completely batshit theories that have no basis in science or reason. But I sometimes liken him to Sigmund Freud, or maybe some of the kookier analytic philosophers, where you read it, it sounds kind of good, and then you get to the end and think, “Well, that’s probably 95 percent bullshit, but it still enriches my worldview.” I feel more enriched for having read it. That doesn’t mean it’s true, and I don’t put much credence in it, but it’s fun to entertain, and I do think it enriches the way I think about the human mind and human possibility. 

You also mention how “what drove [you] to write this book was in part a procession of deaths and their aftermaths” you and your wife endured starting in 2019. Would you elaborate on that? 

About a year into writing the book, my son, who was four at the time, fell ill unexpectedly, out of nowhere. He was in and out of the hospital during those days. It really brought us face to face, for the first time as parents, with real suffering and grief, and with being totally out of control when it came to finding a remedy for him. There was just no help to be found anywhere. I started thinking about grief and suffering, and how much of it was around us.  

Then there was this kind of cascade of deaths—just a lot coming at once over the span of a couple of years. It made me wonder what psychedelics, at least on a therapeutic level, potentially have to offer people: some relief.  

Another thing: My father was, weirdly, at the same time, starting to consider psychedelic-assisted therapy to treat his depression and longstanding addiction to alcohol. Maybe a year before, I’d given him Michael Pollan’s book, How to Change Your Mind: What the New Science Teaches Us About Consciousness, Dying, Addiction, Depression, and Transcendence (2018). Because my dad had been in and out of therapy, rehab, and 12-step programs for many years, I was like, “I don’t know if you’ve heard of this, but I’ve been reading about non-traditional approaches to treating alcohol addiction, including psychedelics.” I don’t think he ever read it, but it did start a conversation between us. 

What surprised you most while researching the book? 

Reading Terence, I hadn’t realized that psilocybin mushrooms were not indigenous to La Chorrera—that they were essentially a foreign import [1], and not something used by the people there, certainly not by shamans. 

Another revelation was what “shamanism” actually looks like in the Colombian Putumayo. Terence talked a lot about this sort of psychedelic shamanism. A lot of people do today, too. But it’s just not at all what it seems to be. The Indigenous perspective on and use of things like ayahuasca, or yagé, and other psychedelic plants—at least in the Putumayo, where Terence and Dennis spent much of their time—is vastly different from how I think they’re generally understood or used in the U.S. These substances were generally not used for healing. Until European contact with Indigenous peoples throughout the Amazon Basin, ayahuasca was mostly used in the hunt—to have luck in finding animals—or sometimes to find lost objects or communicate with family members or other tribe members over long distances. But it was definitely not a therapeutic application. That’s starting to shift a little bit now, though, because of this strange sort of cross-pollination that happens so often in history where it’s now being fed back into an Indigenous context. 

I think I went into the book as something of a Terence fanboy. I cooled on him a bit once I spoke with Colombian anthropologists and ethnobotanists and realized how taken out of context many of his proclamations were on psychedelics and the “shamanic” experience. But, by the end, I sort of warmed to him again because I realized that his ultimate project, I think, was really about human wellness and flourishing. I think that’s what he wanted ultimately, even if he went about it in a strange, myopic way focused almost exclusively on the psychedelic experience through psilocybin mushrooms. That’s where I part ways with him. I think the best place from which to grapple with grief, loss, and suffering is through love, tenderness, and compassion—not through machine elves at the end of history, which was, more or less, Terence’s take. 

I was also interested in your discussion of “diagonalism”—what scholars William Callison and Quinn Slobodian characterize as the social-distress-born alliances between the far left and the far right uniting wellness gurus, anti-vaxxers, and conspiracy theorists. 

I was just reading an article by the American political scientist Francis Fukuyama; he calls it this horseshoe meeting of the minds—this ideological vortex where people with otherwise totally divergent political opinions are meeting in the middle on certain issues. The far left, the Make America Healthy Again movement, the Multidisciplinary Association for Psychedelic Studies—even just the friendship between [MAPS founder] Rick Doblin and former Texas Governor Rick Perry [co-founder of the nonprofit Americans for Ibogaine], who had one of the most conservative legislative agendas in recent memory. That friendship seems genuine—and maybe even necessary to advance these drugs beyond their current legal status. 

In 2023, MAPS hosted the world’s largest psychedelic conference, which you describe as laden with snake oil pseudoscience and lacking in diversity, equity, and inclusion. Almost a year later, an FDA advisory panel rejected MDMA-assisted therapy for PTSD, citing safety concerns and questions about data validity. Critics alleged that MAPS’ drug development arm failed to disclose data showing sexual misconduct by therapists and increased suicidality among trial participants. A former MAPS volunteer called MAPS an exploitative and abusive cult that functions “more like a religious movement than a scientific organization.” Similar concerns emerged at The Johns Hopkins Center for Psychedelic and Consciousness Research. An ethics complaint accused founding director Roland Griffiths of “acting as a ‘spiritual leader’ rather than a scientist” and influencing participant outcomes through religious symbolism. 

Additionally, a Columbia psychiatrist reviewing the field noted a relatively high rate of  irritability, anxiety, insomnia, and other adverse events, and called for more “rigorous assessment” of psilocybin-assisted therapy.  

How do we balance the potential of psychedelics to promote empathy and well-being with the risks? 

Terence said a lot of completely bullshit things about psychedelics—even dangerous things at times. You see that in the movement today, where a lot of these wild, unsubstantiated claims are being made about drugs that, yes, have real healing potential for many people, but for others, such as my father, don’t work at all—and arguably cause more harm than good. 

We should be sane and sober about this. We can champion these drugs while still having a lucid conversation about their efficacy, limitations, and safety concerns. 

[1] One of my favorite passages from the book is “Darkly gilled, with distinctive golden halos and pink veils around slender stems the color of bruised flesh, they were easily identifiable as Psilocybe cubensis… Likely brought to the Americas by Spanish missionaries via the dung of zebu cattle—rangy saltwhite beasts with enormous, scythe-like horns—Psilocybe did especially well in the humid pastures of La Chorrera. Amazonian shamans, who knew more about psychoactive plants than anyone on earth, had no use for these foreign imports. To Terence, however, they were living manifestations of the divine” (p. xx). 

A Short, Strange Trip: An Untold Story of Magic Mushrooms, Madness, and a Search for the Meaning of Life in the Amazon 
John O’Connor 
New York: Sourcebooks 
2026