The Marginalian
The Marginalian

The New Science of Plant Intelligence and the Mystery of What Makes a Mind

The New Science of Plant Intelligence and the Mystery of What Makes a Mind

“A leaf of grass is no less than the journey work of the stars,” Walt Whitman wrote a decade before Darwin gasped at how incomprehensible “the marvelous complexity” of organic beings is, insisting that “each living creature must be looked at as a microcosm — a little universe, formed of a host of self-propagating organisms, inconceivably minute and as numerous as the stars in heaven.”

And yet this view does not come naturally to us humans, sensemaking creatures compelled to order the universe into comprehensible categories and value ranks, compelled to rank ourselves at the top. Even Darwin had to continually calibrate that impulse. “Never say higher or lower,” he exhorted himself in his marginalia on a book he was reading while working out his evolutionary theory. “Say more complicated.”

The crux of our difficulty is both profound and banal — to understand nature through degrees of complexity rather than levels of hierarchy scaffolded with self-reference is to find ourselves no longer the pinnacle of creation. We are only just beginning to comprehending non-human minds, only just beginning to concede that there are infinitely many other ways of seeing and other ways of being within the same reality; we would sooner grant consciousness to AI, modeled on our own minds arising from nervous systems crowned with brains, than consider different forms of intelligence as portals to a wider conception of consciousness.

Dragon arum (Arum dracunculus) from The Temple of Flora, 1812. (Available as a print and as stationery cards, benefitting The Nature Conservancy.)

In The Light Eaters: How the Unseen World of Plant Intelligence Offers a New Understanding of Life on Earth (public library), journalist Zoë Schlanger offers a mighty antidote to our tyranny of self-reference through the emerging science of organic beings we have long treated as stage decor for the drama of our earthly lives — a science rife with controversy and confusion, which is always the mark of a paradigm breaking down and breaking open, contouring a new way of thinking about questions of consciousness, communication, memory, gender, personality, interdependence, and agency. Rising from the pages is that rare achievement of meeting otherness on its own terms while broadening and deepening the terms on which we live our human lives. Schlanger draws from the world of plants “a masterclass in living to one’s fullest, weirdest, most resourceful potential,” and a counterpoint to the survival-of-the-fittest model of the natural world, intimating instead that the animating force of life may be not a combat for a kill but “an improvisation, or a collaboration, or something else entirely.”

A quarter millennium after Darwin’s grandfather popularized the young science of botany through poetry, and two centuries after Emily Dickinson wrote that “to be a Flower is profound Responsibility,” Schlanger writes:

A life spent constantly growing yet rooted in a single spot comes with tremendous challenges. To meet them, plants have come up with some of the most creative methods for surviving of any living thing, us included. Many are so ingenious that they seem nearly impossible for an order of life we’ve mostly relegated to the margins of our own lives, the decoration that frames the theatrics of being an animal. Yet there they are all the same, these unbelievable abilities of plants, defying our anemic expectations. Their way of life is so astonishing, I will soon learn, that no one yet really knows the limits of what a plant can do. In fact, it seemed that no one quite knows what a plant really is.

This perplexity, Schlanger observes, is one of the most exciting things to happen in our lifetime — “depending on how comfortable you feel with seismic shifts in what you once thought to be true.” Looking back on the past half-century of botany, she reflects on this generative discomfort:

Controversy in a scientific field tends to be a harbinger of something new, some new understanding of its subject… The more botanists uncovered the complexity of forms and behaviors of plants, the less the traditional assumptions about plant life seemed to apply.

Auriculas from The Temple of Flora, 1812. (Available as a print and as stationery cards, benefitting The Nature Conservancy.)

One of those assumptions stems from our basic taxonomic model of life on Earth, separated into six kingdoms — as though plants, animals, fungi, and all the rest are separate and sovereign territories of being, bound by borders and occasionally at war for resources. This tendency to mistake our models of reality for reality itself, universal to the human animal and manifested across all cultures in different ways, and this particular blind spot of Western science, unshared by indigenous and Eastern traditions, have left our view of plants on par with Descartes’s view of non-human animals. An epoch after the poetic naturalist John Muir observed that “when we try to pick out anything by itself, we find it hitched to everything else in the universe,” Schlanger writes:

For us to truly be part of this world, to be awake to its roiling aliveness, we need to understand plants. They suffuse our atmosphere with the oxygen we breathe, and they quite literally build our bodies out of sugars they spin from sunlight. They made the ingredients that first allowed our lives to blink into existence at all. Yet they are not merely utilitarian supply machines. They have complex, dynamic lives of their own.

Out of those lives arose an organizing principle for life on Earth. In a passage that contours the central question of the entire field of plant intelligence — how something without a brain can respond to its conditions in coordinated, adaptive ways that optimize its future — Schlanger writes:

When plants climbed out of the ocean some five hundred million years ago, they arrived in a terrestrial barrens enveloped in an inhospitable fog of carbon dioxide and hydrogen. Inhospitable, that is, to everything but plants. They had already learned to unlock oxygen from the carbon dioxide dissolved in the ocean. They adapted the technology to their new world. In a way, they brought the ocean up with them. By incessantly breathing out, those legions of early land plants tipped the balance of gases toward oxygenation. They created the atmosphere we now enjoy. It’s not a stretch to say they birthed the habitable world.

We know this — we know that without the evolution of flowers, we wouldn’t exist; we know that chlorophyll is the crowning molecular miracle of nature, the only thing we know that can convert the inanimate elements of air and light into sugar, that lifeblood of the living world. With an eye to our own embodiment as cathedrals of glucose, Schlanger puts this alchemy in sobering perspective:

We are made of glucose, too. Without a constant supply of the plant sugar, our vital functions would quickly cease. Think about it: every animal organ was built with sugar from plants. The meat of our bones and indeed the bones themselves carry the signature of their molecules. Our bodies are fabricated with the threads of material plants first spun. Likewise, every thought that has ever passed through your brain was made possible by plants.

Page from Emily Dickinson’s herbarium

Drawing on her personal obsession with plants — a portal of wonder and optimism she discovered while suffering the psychic toll of working as a climate journalist — Schlanger seeks out the pioneers of this changing paradigm. She meets a rare-plant botanist on the brink of seventy who climbs down immense volcanic cliffs to save endangered species and self-medicates for the grief of extinction by writing poetry; she chronicles the research that led to the first clear evidence of mechanosensitive ion channels in plants — those rudiments of nervous systems, enabling organisms to experience touch at the cellular level — sparked by botanist Barbara Pickard’s groundbreaking work on plant electricity; she visits with scientists who study the most controversial frontlines of plant intelligence — research that unsteadies our grip on concepts we consider singularly human.

One botanist who studies how sagebrush send distress signals to each other has found that individual plants appear to have different risk tolerance — a metric of personality, the very notion of which in an organism without a brain-based mind challenges our central assumptions about consciousness. Other research on a family of flowering desert shrubs found that female plants heed signals from both male and female plants, but males only heed other males — intimations of preference and judgment, also features of personality and consciousness. Schlanger synthesizes some of the most provocative findings:

Plants could be said to have dialects, and are alert to their contexts enough to know when to deploy them. More than that, they have a clear sense of who is who; who is family, and who is not. They are in touch with their surroundings, and with the fluctuating status of their enemies. Their communication is not just rudimentary but complex and layered, alive with multiple meanings.

In fact, no aspect of this new botany is more paradigm-shifting than the study of plant communication. (Canadian forester Suzanne Simard’s epoch-making research into mycorrhizal tree communication was the fulcrum that began shifting the paradigm.) Schlanger considers how this very notion changes our understanding of nature:

Communication implies a recognition of self and what lies beyond it — the existence of other selves. Communication is the forming of threads between individuals. It’s a way to make one life useful to other lives, to make oneself important to other selves. It turns individuals into a community. If it is true that a whole forest or field is in communication, it changes the nature of that forest or field. It changes the notion of what a plant is.

It also changes the notion of what a mind is. We have taken it to be the product of a brain attached to a nervous system, but perhaps a mind is a complex, self-organizing system networked across the entire organism. Perhaps the whole plant is a mind.

Art by Ofra Amit for The Universe in Verse

Emerging from this particular field of science is a larger lens on the nature of knowledge. A century and a half after astronomer Maria Mitchell contemplated the fate of science, observing that “we reach forth and strain every nerve, but we seize only a bit of the curtain that hides the infinite from us,” Schlanger writes:

The world is a prism, not a window. Wherever we look, we find new refractions.

Couple The Light Eaters with the poetic science of the ghost pipe — Earth’s most supernatural plant, which thrives mysteriously without eating light — then revisit this triptych meditation on flowers and the meaning of life.


No One You Love Is Ever Dead: Hemingway on the Most Devastating of Losses and the Meaning of Life

No One You Love Is Ever Dead: Hemingway on the Most Devastating of Losses and the Meaning of Life

Along the spectrum of losses, from the door keys to the love of one’s life, none is more unimaginable, more incomprehensible in its unnatural violation of being and time, than a parent’s loss of a child.

Ernest Hemingway (July 21, 1899–July 2, 1961) was in his twenties and living in France when he befriend Gerald and Sara Murphy. The couple eventually returned to America when one of their sons fell ill, but it was their other son, Baoth, who died after a savage struggle with meningitis.

Upon receiving the news, the thirty-five-year-old writer sent his friends an extraordinary letter, part consolation for and part consecration of a loss for which there is no salve, found in Shaun Usher’s moving compilation Letters of Note: Grief (public library).

Ernest Hemingway

On March 19, 1935, Hemingway writes:

Dear Sara and Dear Gerald:

You know there is nothing we can ever say or write… Yesterday I tried to write you and I couldn’t.

It is not as bad for Baoth because he had a fine time, always, and he has only done something now that we all must do. He has just gotten it over with…

About him having to die so young — Remember that he had a very fine time and having it a thousand times makes it no better. And he is spared from learning what sort of a place the world is.

It is your loss: more than it is his, so it is something that you can, legitimately, be brave about. But I can’t be brave about it and in all my heart I am sick for you both.

Absolutely truly and coldly in the head, though, I know that anyone who dies young after a happy childhood, and no one ever made a happier childhood than you made for your children, has won a great victory. We all have to look forward to death by defeat, our bodies gone, our world destroyed; but it is the same dying we must do, while he has gotten it all over with, his world all intact and the death only by accident.

Art by Charlotte Pardi from Cry, Heart, But Never Break by Glenn Ringtved — a soulful Danish illustrated meditation on love and loss

In a breathtaking sentiment evocative of Anaïs Nin’s admonition against the stupor of near-living, and of poet Meghan O’Rourke’s grief-honed conviction that “the people we most love do become a physical part of us, ingrained in our synapses, in the pathways where memories are created,” Hemingway adds:

Very few people ever really are alive and those that are never die; no matter if they are gone. No one you love is ever dead.

With this, echoing Auden’s insistence that “we must love one another or die,” he comes the closest he ever came to formulating the meaning of life. Like David Foster Wallace, who addressed the meaning of life with such exquisite lucidity shortly before he was slain by depression, Hemingway too would lose hold of that meaning in the throes of the agony that would take his life a quarter century later. Now, from the fortunate platform of the prime of life, he writes:

We must live it, now, a day at a time and be very careful not to hurt each other. It seems as though we were all on a boat together, a good boat still, that we have made but that we know will never reach port. There will be all kinds of weather, good and bad, and especially because we know now that there will be no landfall we must keep the boat up very well and be very good to each other. We are fortunate we have good people on the boat.

Complement with the young Dostoyevsky’s exultation about the meaning of life shortly after his death sentence was repealed, Emily Dickinson on love and loss, Thoreau on living through loss, and Nick Cave — who lived, twice, the unimaginable tragedy of the Murphys — on grief as a portal to aliveness, then revisit the fascinating neuroscience of your brain on grief and your heart on healing.


The Messiah in the Mountain: Darwin on Wonder and the Spirituality of Nature

The Messiah in the Mountain: Darwin on Wonder and the Spirituality of Nature

Here we are, matter yearning for meaning, each of us a fragile constellation of chemistry and chance hurtling through a cold cosmos that has no accord for our wishes, takes no interest in our dreams. “I can’t but believe that all that majesty and all that beauty, those fated and unfailing appearances and exits, are something more than mathematics and horrible temperatures,” Willa Cather wrote to the love of her life while watching the transcendent spectacle of Jupiter and Venus rising in the summer sky. “If they are not, then we are the only wonderful things — because we can wonder.”

That we can wonder is what saves us. The price evolution had us pay for our exquisite consciousness is an awareness of our mortality — an awareness unbearable without the capacity for wonder at the miracle of existing at all, improbable as we each are against the staggering odds of never having been born, alive on an improbable world unlike any other known. Wonder is the religion nature invented long before we told our first myths of prophets and messiahs, the great benediction of our fate as borrowed stardust on short-term loan from an entropic universe.

A century before the pioneering neuroscientist Charles Scott Sherrington formulated his notion of “Natural Religion,” placing at its center our capacity for and responsibility to wonder, before Rachel Carson insisted that wonder is our greatest antidote to self-destruction and that “natural beauty has a necessary place in the spiritual development of any individual or any society,” the young Charles Darwin (February 12, 1809–April 19, 1882) discovered that experiences of wonder — which he defined as “a chaos of delight” — are profoundly spiritual and come most readily in raw nature.

Charles Darwin in his twenties

In early 1835, with the Beagle docked in Chile for repairs four years into its voyage, the twenty-six-year-old Darwin hired muleteers and set out to cross the Andes on foot and hoof, relishing the exposed face of Earth’s geologic history in the dramatic landscape. By mid-March, he reached the Piuquenes pass connecting Argentina and Chile and began the trying ascent. Breathing became “deep and laborious.” He felt the tightness in his chest. The mules panted and stopped every fifty feet. But when he stumbled upon some fossil shells on the ridge, he “entirely forgot” the altitude sickness in his delight.

And then, approaching the summit against wind “impetuous and extremely cold,” he encountered something belonging to the enchanting canon of the unphotographable.

Standing there amid the austere beauty of the mountain and the elements in their extreme, with petrified pieces of deep time in his pocket, Darwin touched God.

“View of Nature in Ascending Regions” by Levi Walter Yaggy from Geographical Portfolio, 1893. (Available as a print and as stationery cards.)

In an account later included in his memoir A Naturalist’s Voyage Round the World (public library | free ebook), he writes:

When near the summit, the wind, as generally happens, was impetuous and extremely cold. On each side of the ridge we had to pass over broad bands of perpetual snow, which were now soon to be covered by a fresh layer. When we reached the crest and looked backwards, a glorious view was presented. The atmosphere resplendently clear; the sky an intense blue; the profound valleys; the wild broken forms: the heaps of ruins, piled up during the lapse of ages; the bright-coloured rocks, contrasted with the quiet mountains of snow, all these together produced a scene no one could have imagined. Neither plant nor bird, excepting a few condors wheeling around the higher pinnacles, distracted my attention from the inanimate mass. I felt glad that I was alone: it was like watching a thunderstorm, or hearing in full orchestra a chorus of the Messiah.

Complement with Coleridge’s transcendent experience of a thunderstorm and René Daumal on the mountain and the meaning of life, then revisit Darwin’s deathbed reflection on what makes life worth living and the bittersweet story of his beloved daughter.


On Giving Up: Adam Phillips on Knowing What You Want, the Art of Self-Revision, and the Courage to Change Your Mind

On Giving Up: Adam Phillips on Knowing What You Want, the Art of Self-Revision, and the Courage to Change Your Mind

“A self that goes on changing is a self that goes on living,” Virginia Woolf wrote. Nothing is more vital to the capacity for change than the uncomfortable luxury of changing your mind — that stubborn refusal to ossify, the courageous willingness to outgrow your views, anneal your values, and keep clarifying your priorities. It is incredibly difficult to achieve because the very notion of the self hinges on our sense psychological continuity and internal consistency; because we live in a culture whose myths of heroism and martyrdom valorize completion at any cost, a culture that contractually binds the present self to the future self in mortgages and marital vows, presuming unchanging desires, forgetting that who we are is shaped by what we want and what we want goes on changing as we go on growing.

Changing — your mind, your life — is also painfully difficult because it is a form of renunciation, a special case of those necessary losses that sculpt our lives; it requires giving something up — a way of seeing, a way of being — in order for something new to come abloom along the vector of the “endless unfolding” that is a life fully lived, something that leaves your new emerging self more fully met.

One of English artist Margaret C. Cook’s illustrations for a rare 1913 edition of Leaves of Grass. (Available as a print.)

The psychoanalyst Adam Phillips offers a salve for that perennial difficulty in On Giving Up (public library) — an exploration and celebration of giving up as “a prelude, a precondition for something else to happen, a form of anticipation, a kind of courage,” “an attempt to make a different future” that “get us the life we want, or don’t know that we want.”

He considers how countercultural such reframing is:

We tend to value, and even idealize, the idea of seeing things through, of finishing things rather than abandoning them. Giving up has to be justified in a way that completion does not; giving up doesn’t usually make us proud of ourselves; it is a falling short of our preferred selves… Giving up, in other words, is usually thought of as a failure rather than a way of succeeding at something else. It is worth wondering to whom we believe we have to justify ourselves when we are giving up, or when we are determinedly not giving up.

At the heart of the book is the recognition that renunciation is the fulcrum of change. We give things up, Phillips observes, “when we believe we can no longer go on as we are.” (For many, this is the central crisis of midlife.) It is a kind of sacrifice in the service of a larger, better life — but this presumes knowledge of the life we want, and it is often experiences we didn’t know we wanted that end up magnifying our lives in the profoundest ways. (Nothing illustrates this better than The Vampire Problem.)

Phillips considers the paradox:

The whole notion of sacrifice depends upon our knowing what we want… Giving up, or giving up on, anything or anyone always exposes what it is we take it we want… To give something up is to seek one’s own assumed advantage, one’s apparently preferred pleasure, but in an economy that we mostly can’t comprehend, or, like all economies, predict… We calculate, in so far as we can, the effect of our sacrifice, the future we want from it… to get through to ourselves: to get through to the life we want.

Falling Star by Witold Pruszkowski, 1884. (Available as a print.)

“I did not know that I could only get the most out of life by giving myself up to it,” the psychiatrist and artist Marion Milner wrote a century ago in her clarifying field guide to knowing what you really want — which is, in the end, the hardest thing in life, for our self-knowledge is cratered with blind spots, clouded by conditioning, and perennially incomplete. Phillips — who draws on Milner’s magnificent book, as well as on Kafka and Judith Butler, Henry and William James, Hamlet and Paradise Lost — observes that, in this regard, giving up is a kind of “gift-giving.” He writes:

Not being able to give up is not to be able to allow for loss, for vulnerability; not to be able to allow for the passing of time, and the revisions it brings.

And what would life be without continual acts of self-revision?

It is our ego-ideals — the stories we tell ourselves and the world about who we are and who we ought to be, fantasies of coherence and continuity mooring us to a static idealized self — that feed what Phillips calls the “tyranny of completion.” But human beings are rough drafts that continually mistake themselves for the final story, then gasp as the plot changes on the page of living. We do this largely because we are captives of comfort in our habits of thought and feeling, victims of certainty — that supreme narrowing of the mind — when it comes to our own desires. That we don’t fully know what we want because we are half-opaque to ourselves, that something we didn’t think we wanted may end up enlarging our lives in unimaginable ways, is a kind of uncertainty that unravels us. But if we can bear the frustration of the figuring, we may live into a larger and more authentic life.

Art by Francisco de Holanda, 1550s. (Available as a print and as stationery cards.)

Building upon his excellent earlier writing on why frustration is necessary for satisfaction in love, Phillips writes:

Our frustration is the key to our desire; to want something or someone is to feel their absence; so to register or recognize a lack would seem to be the precondition for any kind of pleasure or satisfaction. Indeed, in this account, frustration, a sense of lack, is the necessary precondition for any kind of satisfaction.


The traditional story about lack and desire describes a closed system; in this story I can never be surprised by what I want, because somewhere in myself I already know what is missing; my frustration is the form my recognition takes, it is a form of remembering.

Wanting is recovery, not discovery… There is a part of oneself that needs to know what it is doing, and a part of oneself that needs not to… a part of oneself that needs to know what one wants and a part of oneself that needs not to.

It is in the continual investigation of our desires, with all the frustration of our polyphonous parts, that we find the recovery and gift-giving which giving up can bring — a way of giving our lives back to ourselves and giving ourselves forward to our lives. Phillips distills the central predicament:

The question is always: what are we going to have to sacrifice in order to develop, in order to get to the next stage of our lives?

Couple On Giving Up with John O’Donohue on beginnings, Allen Wheelis on how people change, and Judith Viorst on the life-shaping art of letting go, then revisit Phillips on why we fall in love, breaking free from the tyranny of self-criticism, and the relationship between “fertile solitude” and self-esteem.


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