Robert Moor is the author of “In Trees: An Exploration.”
One wintry day in 1935, the poet E.E. Cummings decided to pay a visit to the Natural History Museum in Manhattan. In a letter to the poet Ezra Pound, he later described the museum, sarcastically, as a kind of “miracle” — a temple of life where nothing (aside from its visitors) was actually alive. Moving past the displays of taxidermied animals, with their glassy eyes and sad yellow teeth, Cummings stepped into a room where he encountered a detailed diagram of the Darwinian tree of life. He appears to have lingered over it for a long time, tracing the branching flow of evolution — the way that a single ancestral line diverged over the eons to create fungi and plants and starfish and frogs and crows and spiders and squids and ocelots and us. Despite his evidently grouchy mood, Cummings seems to have been moved by the “dendronous mechanism” on display. Here was a true miracle. What a tree, he marveled. What a tree …
The evolutionary biologist Robert J. O’Hara calls this way of seeing the world “tree thinking.” Instead of viewing biology as an array of static groups arranged in a hierarchy, with God on top and germs on the bottom — or as a steady teleological march toward human supremacy — tree thinking encourages us to see life on earth as a sprawling process of experimentation (and, yes, extinction), where everything is fundamentally related to everything else.
If, like O’Hara, we can learn to envision a tree as a way of being rather than just a type of being, it’s possible to divide arborescence into four entwined processes: branching, pruning, gnarling, and rooting. Broken down like this, something that initially sounds absurd is revealed to be quite achievable. A person can learn to think like a tree. (By this, I don’t mean to think the way a tree thinks — if a tree thinks — but rather to think as a tree is.)
To think like a tree, one must begin by branching out: Try everything. Consider many possibilities at once. Be radically open-minded. Reject reductiveness. Instead of defaulting to “either/or” questions, ask yourself if the answer might be “both/and.”
As the mind branches out, it must also learn to prune back: Continually test your beliefs. Pare away falsities and bad ideas. Be rigorous. Self-edit.
Then comes the task of gnarling: If you’ve struck upon a useful solution, bolster it. Do not abandon wise old ideas simply for novelty’s sake, but do not allow them to dessicate into relics, either. Keep them alive or let them go.
The final element of tree thinking is to maintain deep roots: Try to see the world in a way that is localized, contextualized, and communally oriented. Arborescent thought must be firmly rooted — in the land and in the lives of other species. Otherwise, it is groundless.
Once you start thinking like a tree, you begin to recognize this quality in others. Many great artists, writers, and scientists throughout history have cultivated brains that are capacious, experimental, rigorous, and rooted: Leonardo da Vinci, Leo Tolstoy, Toni Morrison, Denis Diderot, Virginia Woolf, Lynn Marguiles, Alexander von Humboldt, Franz Boas, Kwame Anthony Appiah, Miguel Ángel Asturias, Viola Cordova, Henry David Thoreau, Santiago Ramón y Cajal, Martin Buber, Italo Calvino, Ibn Sina, Tyson Yunkaporta, Saigyo, and Siddhartha Gautama are all distinctly arborescent thinkers. (It’s worth noting that many of these thinkers also spent a great deal of time around trees, whether they were sitting beneath them, like the Buddha; drawing them, like Leonardo; or tending to them, like Tolstoy. I have a strong suspicion that regularly interacting, and even empathizing, with trees naturally arborizes the mind.)
One of the most notable social shifts over the past century has been the use of arborescent logic to splinter strict binaries and explode oppressive hierarchies. Medieval nobles saw race as consisting of only two categories: There were those with “clean” (noble) blood and those without. Benjamin Franklin, likewise, divided the world into a small number of people who were “purely white,” as he was, and the world’s nonwhite hordes (among whom he included the “swarthy” Germans and Swedes). Since then, our view of race has, thankfully, undergone a process of radical arborization: We now recognize that race is little more than a branching lineage of genotypes, retroactively arranged into fuzzy categories. Likewise, modern anthropologists widely agree that all human societies are linked, not ranked — mere ramifications of what the American anthropologist Ralph Linton called the “Tree of Culture.” Our understanding of sex and gender has begun to arborize, too; rather than the stark binaries of male and female, gay and straight, most open-minded people now see branches and subbranches of sexual identities reaching out in all directions.
Arborescence has proved equally transformative in the political sphere. Following the European Enlightenment, the absolute power of the monarchy, once the norm across much of the world, began to break apart and fan out. Healthy democracies — what philosopher Karl Popper aptly called “open societies” — are marked by checks and balances among various “branches” of government, equitable wealth redistribution, strong civil liberties, a faith in empiricism, and a firm belief in the unity of humankind. All of these liberatory developments are ones that those with reductive and repressive minds naturally oppose.
Ironically enough, the term “arborescence” was coined by the philosophers Gilles Deleuze and Felix Guattari to function as a kind of slur. They believed that because all of the branches of a tree flow down into a single trunk, like so many officers reporting to a generalissimo, the tree represents the basic structure of fascism. But subsequent thinkers like Michael Marder have convincingly argued that Deleuze and Guattari “got arborescence all wrong.” Trees, notes Marder, “can branch out in quite unpredictable ways; they can accommodate the grafts of other species; they can give rise to shoots that can survive independently of them; they can change their sexes or become hermaphrodites for a limited stretch or for the rest of their lives; and the list continues.”
A tree is too weird, too wild, to embody the spirit of totalitarianism. Indeed, it embodies the very things — open-mindedness, truth-seeking, a way of being rooted in what indigenous philosophers call “relationality” — that totalitarianism most fears.
Immanuel Kant once wrote of the need for a “revolution” in our “shape of mind.” In these strange and chaotic times, when so many people’s minds resemble either teetering towers or atomized clouds, the remedy for our philosophical maladies has been right in front of us all along. We need only to look to the trees.