The Ladder, The Sphere And The Rhizome

Claire Isabel Webb is a historian and anthropologist of science. She is a 2020-22 Berggruen Institute fellow.

Six millennia ago in what is now Serbia, a woman was breaking down a deer that had been killed with a spear tipped with smelted copper. She did not think to herself: “Ah, how good it is to be alive now in the Copper Age, but the sharper knives they’ll have in the Bronze Age in the future would really help me saw through these ligaments.”

In the late 7th century B.C.E. on the Greek island of Lesbos, the poet Sappho wrote an ode to Aphrodite, the goddess of love, beseeching her for help to pursue a lover. Sappho would not have placed herself in Greece’s Archaic Age, nor would she have known she was helping lay the groundwork for the flowering of art in the Classical Age. 

And in 1637 when the French philosopher René Descartes penned, “Je pense, donc je suis” — “I think, therefore I am” — he could not have predicted how the concept of reason in the nascent Age of Enlightenment would be challenged by novel subjects like artificial intelligences centuries later. 

“How we assemble the past — how we delineate epistemes materially and conceptually — inflects how we form the future.”

Each of these three people lived in a particular “episteme,” a Greek word that delimits eras of knowledge and craft. Michel Foucault, another French philosopher, argued that every episteme is bound by incommensurable cultural codes. “In any given culture and at any given moment,” he wrote in 1966, “there is always only one episteme that defines the conditions of possibility of all knowledge, whether expressed in a theory or silently invested in a practice.” 

Researching how people from prehistory to ancient Greece to Enlightenment Europe hunted, loved and wrote helps us structure the past. But a new era of knowledge does not cleanly follow on the heels of its predecessor. Earlier ways of thinking and creating are regurgitated unpredictably in later eras. Scholarly consensus about the precise moment at which one knowledge tradition gives way to the next only emerges after the epistemic dust has settled. Our retrofitted paradigms do not chart a linear pathway in time, but instead are metaphoric orders that have appeared, overlapped and recurred in the Western philosophical tradition for millennia.

The root of episteme, “histanai” — to stand — suggests that assigning past knowledge paradigms is a way to place ourselves in history. That exercise contextualizes present ruptures: the collapse of interconnected planetary ecosystems, the exploration of worlds beyond Earth and weirdly behaving matter from the quantum to the cosmological. Moreover, how we assemble the past — how we delineate epistemes materially and conceptually — inflects how we form the future. 

We can imagine those forms as a ladder, a sphere and a rhizome.

A Chain Of Being 

In a series of now-famous lectures at Harvard in 1933, the philosopher Arthur Lovejoy argued that for millennia, Western thinkers perceived their world through a “great chain of being.” In this ancient worldview, every possible kind of life or thing observed and imaginable scaled to the perfection of its form. In Aristotle’s “History of Animals,” for instance, a lion was superior to a rabbit, a sapphire was superior to sand. One entity shaded into the next, always in a hierarchical relation. Men and women both had teeth, but women had fewer. (He was wrong, of course, but you can guess what the insufficiency implied.) As Lovejoy summarized of Aristotelian biology, “Nature loves twilight zones.” 

The shape of this episteme — a hierarchical stack of concatenated entities — percolated throughout the ancient world and resonated for centuries. Thomas Aquinas reworked the chain of being in the Middle Ages for Christian theology. (Socrates’s daemons became Seraphims, an order of angel nearest to God; chthonic deities in the Greek underworld were translated to hell-dwelling devils.) Man remained in the middle: not ethereally perfect, but still master of the Earth and all its creatures. 

“The shape of the episteme was moldable.”

What became known as the scala naturae — the ladder of life — continued to shape Western philosophy. The 17th-century English philosopher John Locke cited the “magnificent harmony of the universe” in which beings “by gentle degrees, ascend upwards from us towards [God’s] infinite perfection, as we see [animals] gradually descend from us downwards.” The German philosopher Immanuel Kant even shuttled the scala naturae to outer space, writing that humans need not envy “the most sublime classes of rational creatures, which inhabit Jupiter or Saturn” because man could “find contentment and satisfaction by turning his gaze upon those lower grades which, in the planets Venus and Mercury, are far below the perfection of human nature.” 

But whereas Aristotle’s ancient worldview described preordained echelons of being (slaves were not fully human and women were not citizens), Locke and Kant instead envisioned radical political equality. For them, every man’s purpose was to fulfill his being and seek universal truths through reason. Enlightenment ideas became the philosophical base for toppling ancien régimes, separating the church from the state and ending slavery. 

Separated by millennia, the ancient and the Enlightenment philosophers thus applied the metaphor of the great chain of being in different ways to order their world. The shape of the episteme was moldable. 

Cosmological Spheres

As centuries unfolded, different epistemic shapes bent to each other and intertwined. The vertical stack always intersected with circles and spheres. In ancient Greek philosophy, the Okeanos was a mighty body of water that encompassed the world. The Orphic Egg hatched the Phanes, the progenitor of all other goddesses and gods. Millenia later, the Greco-Egyptian astronomer Ptolemy codified a geocentric model of the cosmos in which the sun, stars and planets ringed the Earth. In this hierarchy of circles, each object occupied its own plane and radiated outward from the Earth.

Even as mathematicians in medieval Persia pointed out anomalies in the geocentric model of the universe, European astronomers preserved Ptolemy’s rendering of it ad hoc for centuries. But in the 16th century, the astronomer Nicolaus Copernicus’s meticulous observations led him to dramatically rescale the universe toward the spherical. Swapping the rotation of the Earth with the rotation of the heavens, Copernicus’ dense calculations solved for the apparent motion of the stars and the retrograde motion of the planets. Earth was no longer the immobile center of the universe. The planet orbited the sun.

When humans first saw the Earth from outer space in the 1960s, the planet was reframed as a delicate sphere of life in peril. The scientists James Lovelock and Lynn Margulis co-developed the “Gaia hypothesis” in which the planet’s biosphere was “an active adaptive control system able to maintain the Earth in homeostasis.” Although controversial, the Gaia hypothesis continues to inform the concept of a bounded Earthly sphere, spurring environmental action and suggesting the need for a new planetary politics

Tentacular Rhizomes

Biologies and the biosphere increasingly co-shape and cross-pollinate each other’s interconnected futures, further interrupting past epistemes. Filaments of knowledge pop up unexpectedly, sewing themselves into surprising places. Ideas are dislodged from their original context and sprout in novel ways. Perhaps the current episteme is best rendered as a rhizome: a subterranean plant stem that can shoot out roots that grow, hydralike, even when snipped in two. 

The French thinkers Gilles Deleuze and Félix Guattari plumbed the philosophical concept of the rhizome in the 1970s to describe systems without beginning or end, “always in the middle, between things, interbeing, intermezzo.” The rhizome’s nomadism knits heterogeneous but connected nodes of knowledge from politics to language. 

Consider the massive Armillaria ostoyae in eastern Oregon that is fondly nicknamed the “humungous fungus” and thought to be among the largest and oldest organisms on Earth. It can send out what are called rhizomorphs, mycelian strands that ferry nutrients to distant parts of the organism. In its enormity and longevity, Armillaria ostoyae eludes both origin and finality, characteristics whose absences express the core of Deleuze and Guattari’s concept of the rhizome.

“Epistemic fractures and reorderings do not mark easy passages from one dominant paradigm to another.” 

The rhizome’s conceptual and material multiplicity subverts the scala naturae’s dictum that there is unique place for every creature and thing. Humans comingle with viruses and microorganisms (archaea, bacteria, fungi, protists) that live on and within us. They mold our actions, health, identities — indeed, our very DNA — prompting us to rethink what it means to be corporeally bounded individual humans.

The episteme of the rhizome emphasizes humans’ ineluctable entanglement with nonhuman others. The anthropologist Anna Tsing followed the matsutake mushroom, a delicacy that can’t be cultivated, only foraged in forests disturbed by humans. In the mushroom’s global rhizomatic journey, Tsing theorized the “patchiness” of Earth’s precarity under an extractive-capitalistic ethos of human domination over nature. The philosopher Donna Haraway described “tentacular thinking” with nonhuman others from spiders to tardigrades as “life lived along lines  —  and such a wealth of lines  —  not at points, not in spheres.” 

Patchy, tentacular orientations to lively others allow for multiple futures to simultaneously emerge, a rebellion against the strictures of the stack and the enclosure of the sphere. Interspecies encounters mutate what it is to be human and suggest how we might better care for others we’re enmeshed with. 

Mysterious Shapes 

In their radical decentering of human senses of time and space, the quantum and cosmological realms resist the imposition of a familiar epistemic geometry. We find disjuncture and mystery at the edges of scientific experimentation. What Albert Einstein called “spooky action at a distance” is the bizarre phenomenon in which particles coordinate instantaneously, breaking the speed of light. An MIT team recently observed that even photons emitted from stars light-years apart are correlated. The particles are quantumly entangled but could hardly be more physically dislocated.  

At the cosmic scale, only 5% of the mass and energy of the universe is baryonic or ordinary matter, the stuff of protons and neutrons, iPhones and blue whales. About a quarter is dark matter that defines how gravity shapes our Milky Way and other galaxies. The rest is a force still more bewildering: dark energy. Some cosmologists think dark energy could be the force accelerating the universe’s expansion. 

Scientists at the Large Hadron Collider at CERN near Geneva are whipping up particle beams to nearly the speed of light. The beams’ collisions peel back time, revealing a younger, hotter universe just seconds after the Big Bang. These experiments can’t be integrated into the classically organized, well-ordered universe, be that hierarchical, spherical or rhizomatic. Winking in and out of their manufactured existence, elusive particles could one day provide answers to many of the mysteries of quantum and cosmological spacetimes and plot the future of an increasingly dislocated universe.


A ladder, a sphere, a rhizome: Each epistemic shape has ordered concepts and materials to make sense of the world. There are other shapes, of course — the tree of life, a labyrinth, a pyramid. The practice of structuring past eras of natural philosophy reflects our present lens of knowledge.

Philosophers, scientists and historians retroactively place beginnings and ends on various epistemes, but sorting out each era’s fuzzy lines in real-time is a curious endeavor. In what we tend to think of as punctuated revolutions, knowledge dissemination takes time. Copernicus hesitated to publish “On the Revolutions of the Heavenly Spheres” for decades, and the book did not send 16th-century Italians tearing through Padua declaring that the Earth orbited the sun. Even if dark matter were to be detected tomorrow, a full scientific appreciation of its contents, not to mention the ensuing cultural aftershocks, would take much longer. 

Past epistemic formations often resurface in surprising ways. Einstein shoehorned a “cosmological constant” into his theory of general relativity to reconcile it with astrophysical models. But he abandoned it years later when new observations suggested that the universe was expanding rather than static; he called it his “biggest blunder.” Recently, however, cosmologists have begun to reevaluate the cosmological constant, thinking it could help explain the mysterious force of dark energy. 

Epistemic fractures and reorderings do not mark easy passages from one dominant paradigm to another. They instead signify how we moderns mix metaphors that are stable one day and radically contested the next. “When eras are on the decline, all tendencies are subjective,” the German philosopher Johann Wolfgang von Goethe wrote, “But, on the other hand, when matters are ripening for a new epoch, all tendencies are objective. Each worthy effort turns its force from the inward to outward world.” As we look outward, we sense future epistemes, shimmering over the event horizon of knowability, that have not yet taken shape.