How to Change Your Mind

by Michael Pollan

  “I don’t know if I want to answer it,” he said with a laugh, glancing at my tape recorder. “It depends on which hat I’m wearing.”

  Roland Griffiths had more than one hat! I only had one, I realized, and that made me feel a little jealous.

  Compared with many scientists—or for that matter many spiritual types—Roland Griffiths possesses a large measure of what Keats, referring to Shakespeare, described as “negative capability,” the ability to exist amid uncertainties, mysteries, and doubt without reaching for absolutes, whether those of science or spirituality. “It makes no more sense to say I’m 100 percent convinced of a material worldview than to say I’m 100 percent convinced of the literal version of the Bible.”

  At our last meeting, a dinner at a bistro in his Baltimore neighborhood, I tried to engage Griffiths in a discussion of the ostensible conflict between science and spirituality. I asked him if he agreed with E. O. Wilson, who has written that all of us must ultimately choose: either the path of science or the path of spirituality. But Griffiths doesn’t see the two ways of knowing as mutually exclusive and has little patience for absolutists on either side of the supposed divide. Rather, he hopes the two ways can inform each other and correct each other’s defects, and in that exchange help us to pose and then, possibly, answer the big questions we face. I then read to him a letter from Huston Smith, the scholar of comparative religion who in 1962 had volunteered in Walter Pahnke’s Good Friday Experiment. It was written to Bob Jesse shortly after the publication of Griffiths’s landmark 2006 paper; Jesse had shared it with me.

  “The Johns Hopkins experiment shows—proves—that under controlled, experimental conditions, psilocybin can occasion genuine mystical experiences. It uses science, which modernity trusts, to undermine modernity’s secularism. In doing so, it offers hope of nothing less than a re-sacralization of the natural and social world, a spiritual revival that is our best defense against not only soullessness, but against religious fanaticism. And it does so in the very teeth of the unscientific prejudices built into our current drug laws.”

  As I read Smith’s letter aloud, a smile bloomed across Griffiths’s face; he was clearly moved but had little to add except to say, “That’s beautiful.”

  CHAPTER TWO

  NATURAL HISTORY

  Bemushroomed

  AT THE END of my first meeting with Roland Griffiths, the session in his Johns Hopkins office where he engaged me on the topics of his own mystical experience, my assessment of the odds of an afterlife, and the potential of psilocybin to change people’s lives, the scientist stood up from his desk, unfolding his lanky frame, and reached into the pocket of his trousers to take out a small medallion.

  “A little gift for you,” he explained. “But first, you must answer a question.

  “At this moment,” Griffiths began, locking me in firm eye contact, “are you aware that you are aware?” Perplexed, I thought for a long, self-conscious moment and then replied in the affirmative. This must have been the correct answer, because Griffiths handed me the coin. On one side was a quartet of tall, slender, curving Psilocybe cubensis, one of the more common species of magic mushroom. On the back was a quotation from William Blake that, it occurred to me later, neatly aligned the way of the scientist with that of the mystic: “The true method of knowledge is experiment.”

  It seems that the previous summer Roland Griffiths had gone for the first time to Burning Man (had I heard of it?), and when he learned that no money is exchanged in the temporary city, only gifts, he had the mushroom medallions minted so he would have something suitable to give away or trade. Now, he gives the coins to volunteers in the research program as a parting gift. Griffiths had surprised me once again. Or twice. First, that the scientist had attended the arts-and-psychedelics festival in the Nevada desert. And, second, that he had seen fit in choosing his gift to honor the psilocybin mushroom itself.

  On one level, a mushroom medallion made perfect sense: the molecule that Griffiths and his colleagues have been working with for the last fifteen years does, after all, come from a fungus. Both the mushroom and its psychoactive compound were unknown to science until the 1950s, when the psilocybin mushroom was discovered in southern Mexico, where Mazatec Indians had been using “the flesh of the gods,” in secret, for healing and divination since before the Spanish conquest. Yet, apart from the decorative ceramic mushroom on the shelf in the session room, there are few if any reminders of “magic mushrooms” in the lab. No one I spoke to at Hopkins ever mentioned the rather astonishing fact that the life-changing experiences their volunteers were reporting owed to the action of a chemical compound found in nature—in a mushroom.

  In the laboratory context, it can be easy to lose sight of this astonishment. All of the scientists doing psychedelic research today work exclusively with a synthetic version of the psilocybin molecule. (The mushroom’s psychoactive compound was first identified, synthesized, and named in the late 1950s by Albert Hofmann, the Swiss chemist who discovered LSD.) So the volunteers ingest a little white pill made in a lab, rather than a handful of gnarly and acrid-tasting mushrooms. Their journeys unfold in a landscape of medical suites populated, figuratively speaking, by men and women in white coats. I suppose this is the usual distancing effect of modern science at work, but here it is compounded by a specific desire to distance psilocybin from its tangled roots (or I should say, mycelia) in the worlds of 1960s counterculture, Native American shamanism, and, perhaps, nature itself. For it is there—in nature—that we bump up against the mystery of a little brown mushroom with the power to change the consciousness of the animals that eat it. LSD too, it is easy to forget, was derived from a fungus, Claviceps purpurea, or ergot. Somehow, for some reason, these remarkable mushrooms produce, in addition to spores, meanings in human minds.

  In the course of my days spent hanging around the Hopkins lab and hours spent interviewing people about their psilocybin journeys, I became increasingly curious to explore this other territory—that is, the natural history of these mushrooms and their strange powers. Where did these mushrooms grow, and how? Why did they evolve the ability to produce a chemical compound so closely related to serotonin, the neurotransmitter, that it can slip across the blood-brain barrier and temporarily take charge of the mammalian brain? Was it a defense chemical, intended to poison mushroom eaters? That would seem to be the most straightforward explanation, yet it is undermined by the fact the fungus produces the hallucinogen almost exclusively in its “fruiting body”—that part of the organism it is happiest to have eaten. Was there perhaps some benefit to the mushroom in being able to change the minds of the animals that eat it?*

  There were also the more philosophical questions posed by the existence of a fungus that could not only change consciousness but occasion a profound mystical experience in humans. This fact can be interpreted in two completely different ways. On the first interpretation, the mind-altering power of psilocybin argues for a firmly materialist understanding of consciousness and spirituality, because the changes observed in the mind can be traced directly to the presence of a chemical—psilocybin. What is more material than a chemical? One could reasonably conclude from the action of psychedelics that the gods are nothing more than chemically induced figments of the hominid imagination.

  Yet, surprisingly, most of the people who have had these experiences don’t see the matter that way at all. Even the most secular among them come away from their journeys convinced there exists something that transcends a material understanding of reality: some sort of a “Beyond.” It’s not that they deny a naturalistic basis for this revelation; they just interpret it differently.

  If the experience of transcendence is mediated by molecules that flow through both our brains and the natural world of plants and fungi, then perhaps nature is not as mute as Science has told us, and “Spirit,” however defined, exists out there—is immanent in nature, in other words, just as countless premodern cultures
have believed. What to my (spiritually impoverished) mind seemed to constitute a good case for the disenchantment of the world becomes in the minds of the more psychedelically experienced irrefutable proof of its fundamental enchantment. Flesh of the gods, indeed.

  So here was a curious paradox. The same phenomenon that pointed to a materialist explanation for spiritual and religious belief gave people an experience so powerful it convinced them of the existence of a nonmaterial reality—the very basis of religious belief.

  I hoped that getting to know the psychoactive LBMs (mycologist shorthand for “little brown mushrooms”) at the bottom of this paradox might clarify the matter or, perhaps, somehow dissolve it. I was already something of a mushroom hunter, secure in my ability to identify a handful of edible woodland species (chanterelles, morels, black trumpets, and porcini) with a high enough degree of confidence to eat what I found. However, I had been told by all my teachers that the world of LBMs was far more daunting in its complexity and peril; many if not most of the species that can kill you are LBMs. But perhaps with some expert guidance, I could add a Psilocybe or two to my mushroom hunting repertoire and in the process begin to unpack the mystery of their existence and spooky powers.

  * * *

  • • •

  THERE WAS NEVER any doubt who could best help me on this quest, assuming he was willing. Paul Stamets, a mycologist from Washington State who literally wrote the book on the genus Psilocybe,* in the form of the authoritative 1996 field guide Psilocybin Mushrooms of the World. Stamets has himself “published”—that is, identified and described in a peer-reviewed journal—four new species of Psilocybe, including azurescens, named for his son Azureus* and the most potent species yet known. But while Stamets is one of the country’s most respected mycologists, he works entirely outside the academy, has no graduate degree, funds most of his own research,* and holds views of the role of fungi in nature that are well outside the scientific mainstream and that, he will gladly tell you, owe to insights granted to him by the mushrooms themselves, in the course of both close study and regular ingestion.

  I’ve known Stamets for years, though not very well and always from what I confess has been a somewhat skeptical distance. His extravagant claims for the powers of mushrooms and eyebrow-elevating boasts about his mushroom work with institutions like DARPA (the Pentagon’s Defense Advanced Research Projects Agency) and NIH (the National Institutes of Health) are bound to set off a journalist’s bullshit detector, rightly or—as often happens in his case—wrongly.

  Over the years, we’ve found ourselves at some of the same conferences, so I’ve had several opportunities to hear his talks, which consist of a beguiling (often brilliant) mash-up of hard science and visionary speculation, with the line between the two often impossible to discern. His 2008 TED talk, which is representative, has been viewed online more than four million times.

  Stamets, who was born in 1955 in Salem, Ohio, is a big hairy man with a beard and a bearish mien; I was not surprised to learn he once worked as a lumberjack in the Pacific Northwest. Onstage, he usually wears what appears to be a felt hat in the alpine style but which, as he’ll explain, is in fact made in Transylvania from something called amadou, the spongy inner layer of the horse’s hoof fungus (Fomes fomentarius), a polypore that grows on several species of dead or dying trees. Amadou is flammable and in ancient times was used to start and transport fires. Ötzi, the five-thousand-year-old “Ice Man” found mummified in an alpine glacier in 1991, was carrying a pouch in which he had a piece of amadou. Because of its antimicrobial properties, Fomes fomentarius was also used to dress wounds and preserve food. Stamets is so deep into the world of fungi there’s frequently one perched on top of his head.

  Fungi constitute the most poorly understood and underappreciated kingdom of life on earth. Though indispensable to the health of the planet (as recyclers of organic matter and builders of soil), they are the victims not only of our disregard but of a deep-seated ill will, a mycophobia that Stamets deems a form of “biological racism.” Leaving aside their reputation for poisoning us, this is surprising in that we are closer, genetically speaking, to the fungal kingdom than to that of the plants. Like us, they live off the energy that plants harvest from the sun. Stamets has made it his life’s work to right this wrong, by speaking out on their behalf and by demonstrating the potential of mushrooms to solve a great many of the world’s problems. Indeed, the title of his most popular lecture, and the subtitle of his 2005 book, Mycelium Running, is “How Mushrooms Can Help Save the World.” By the end of his presentation, this claim no longer sounds hyperbolic.

  I can remember the first time I heard Stamets talk about “mycoremediation”—his term for the use of mushrooms to clean up pollution and industrial waste. One of the jobs of fungi in nature is to break down complex organic molecules; without them, the earth would long ago have become a vast, uninhabitable waste heap of dead but undecomposed plants and animals. So after the Exxon Valdez ran aground off the coast of Alaska in 1989, spilling millions of gallons of crude oil into Prince William Sound, Stamets revived a long-standing idea of putting fungi to work breaking down petrochemical waste. He showed a slide of a steaming heap of oily black sludge before inoculating it with the spores of oyster mushrooms, and then a second photograph of the same pile taken four weeks later, when it was reduced by a third and covered in a thick mantle of snowy white oyster mushrooms. It was a performance, and a feat of alchemy, I won’t soon forget.

  But Stamets’s aspirations for the fungal kingdom go well beyond turning petrochemical sludge into arable soil. Indeed, in his view there is scarcely an ecological or medical problem that mushrooms can’t help solve.

  Cancer? Stamets’s extract of turkey tail mushrooms (Trametes versicolor) has been shown to help cancer patients by stimulating their immune systems. (Stamets claims to have used it to help cure his mother’s stage 4 breast cancer.)

  Bioterrorism? After 9/11, the federal government’s Bioshield program asked to screen hundreds of the rare mushroom strains in Stamets’s collection and found several that showed strong activity against SARS, smallpox, herpes, and bird and swine flu. (If this strikes you as implausible, remember that penicillin is the product of a fungus.)

  Colony collapse disorder (CCD)? After watching honeybees visiting a woodpile to nibble on mycelium, Stamets identified several species of fungus that bolster the bees’ resistance to infection and CCD.

  Insect infestation? A few years ago, Stamets won a patent for a “mycopesticide”—a mutant mycelium from a species of Cordyceps that, after being eaten by carpenter ants, colonizes their bodies and kills them, but not before chemically inducing the ant to climb to the highest point in its environment and then bursting a mushroom from the top of its head that releases its spores to the wind.

  The second or third time I watched Stamets show a video of a Cordyceps doing its diabolical thing to an ant—commandeering its body, making it do its bidding, and then exploding a mushroom from its brain in order to disseminate its genes—it occurred to me that Stamets and that poor ant had rather a lot in common. Fungi haven’t killed him, it’s true, and he probably knows enough about their wiles to head off that fate. But it’s also true that this man’s life—his brain!—has been utterly taken over by fungi; he has dedicated himself to their cause, speaking for the mushrooms in the same way that Dr. Seuss’s Lorax speaks for the trees. He disseminates fungal spores far and wide, helping them, whether by mail order or sheer dint of his enthusiasm, to vastly expand their range and spread their message.

  * * *

  • • •

  I DON’T THINK I’m saying anything about Paul Stamets to which he would object. He writes in his book that mycelia—the vast, cobwebby whitish net of single-celled filaments, called hyphae, with which fungi weave their way through the soil—are intelligent, forming “a sentient membrane” and “the neurological network of nature.” The title of his book Mycelium Running can be
read in two ways. The mycelium is indeed always running through the ground, where it plays a critical role in forming soils, keeping plants and animals in good health, and knitting together the forest. But the mycelium are also, in Stamets’s view, running the show—that of nature in general and, like a neural software program, the minds of certain creatures, including, he would be the first to tell you, Paul Stamets himself. “Mushrooms are bringing us a message from nature,” he likes to say. “This is a call I’m hearing.”

  Yet even some of Stamets’s airier notions turn out to have a scientific foundation beneath them. For years now, Stamets has been talking about the vast web of mycelia in the soil as “Earth’s natural Internet”—a redundant, complexly branched, self-repairing, and scalable communications network linking many species over tremendous distances. (The biggest organism on earth is not a whale or a tree but a mushroom—a honey fungus in Oregon that is 2.4 miles wide.) Stamets contends that these mycelial networks are in some sense “conscious”: aware of their environment and able to respond to challenges accordingly. When I first heard these ideas, I thought they were, at best, fanciful metaphors. Yet in the years since, I’ve watched as a growing body of scientific research has emerged to suggest they are much more than metaphors. Experiments with slime molds have demonstrated these organisms can navigate mazes in search of food—sensing its location and then growing in that direction. The mycelia in a forest do link the trees in it, root to root, not only supplying them with nutrients, but serving as a medium that conveys information about environmental threats and allows trees to selectively send nutrients to other trees in the forest.* A forest is a far more complex, sociable, and intelligent entity than we knew, and it is fungi that organize the arboreal society.