Materialist Prehistories
3 Plastic Matters
Jess Keiser
Tufts University
What binds together new materialists, write Diana Coole and Samantha Frost (2010) in their seminal collection on the subject, “is an antipathy towards oppositional ways of thinking” (8).1 Indeed, the founding gesture of new materialism involves banishing a binary. The new materialist argues that human subjects and matter are not opposed but rather fundamentally similar in nature; they both have the capacity for agency, vitality, and cre-ativity.2 But curiously new materialism’s monism—its belief that agency belongs as much to brute matter as it does to human beings—is instituted upon a dualism. One thing the new materialism cannot accord, and there-fore must reject, is any ontology that casts matter as essentially inert or passive in nature.
And for good reason. As Coole and Frost (2010) note, to imagine matter as inherently passive is to breed the very dualisms that shatter new mate-rialism’s monism. Coole and Frost trace this conception of matter—all too common in their view—to seventeenth-century thinkers like Descartes and Newton. The Cartesian–Newtonian view sees matter “as extended, uniform, and inert,” as made up of “solid, bounded objects that occupy space and whose movements or behaviors are predictable, controllable, and replicable because they obey fundamental and invariable laws of motion” (Coole and Frost 2010, 7, 8). If this matter moves at all it does so not because some inherent force or sensitivity drives it along but because something external knocks against it. And yet, as Coole and Frost go on to note, the “corol-lary of this calculable natural world was not, as one might have expected, a determinism that renders human agency an illusion but a sense of mastery bequeathed to the thinking subject” (8). In other words, because matter is imagined as inert, passive, and static, the human subject along with human culture is charged with “making sense of nature by measuring and classify-ing it from a distance but also … manipulat[classify-ing] and reconfigur[classify-ing] matter on an unprecedented scale” (8). In this sense, dualism results as much from a certain conception of matter as it does from (perhaps more familiar) argu-ments concerning the unique capacities of incorporeal souls, divine minds, and human culture.
By the end of their introduction, then, Coole and Frost (2010) have clearly drawn battle lines. On one side is inert, passive matter; the sort of substance
that creates divisions by necessitating the existence of some exogenous force (usually a human or divine being) capable of acting upon matter’s passivity.
On the other side is vital, active matter; the sort of substance that, since it evinces the same capacities we usually attribute solely to humans (or human culture), can mend monism. According to the new materialists, the modern inheritors of Cartesian–Newtonian passive matter theories are not only, as we might expect, scientists and engineers who seek to control and manipu-late the natural world, but also the humanists who, by focusing entirely on culture and language to the detriment of the non-human world, continu-ally treat matter as, at best, a passive surface upon which cultural codes are inscribed or, at worst, an imaginative construct of those same codes.3 Humanist scholarship “that presumes matter’s passivity or plasticity in the face of [socio-cultural] power may echo an earlier ontology for which mat-ter is inert stuff awaiting cultural imprint” (Coole and Frost 2010, 26).
Arrayed against these forces, of course, is the new materialism, a move-ment that seeks to break the humanities’ single-minded focus on language and culture by reorienting it towards a view of vital, active, generative, or creative matter.4 Once one has granted matter’s inherent activity, the dual-ist image of human beings as creatures uniquely capable of understanding, manipulating, and mastering passive substance loses its grip. “Instead, the human species,” write Coole and Frost is, “relocated within a natural envi-ronment whose material forces themselves manifest certain agentic capacities and in which the domain of unintended or unanticipated effects is consider-ably broadened” (10). In even more striking language, Stacey Alaimo and Susan Hekman (2008) remind us that “nature ‘punches back’ at humans and the machines they construct to explore it in ways that we cannot pre-dict” (7). In this broader, more conceptual sense, “active” does not simply denominate matter’s liveliness or its capacity for self-movement or inherent creativity (although various new materialists will emphasize precisely those qualities). On the contrary, matter is “active,” in this more fundamental way, when it behaves as an agent in a network of other entities and forces.
The new materialism, inspired primarily by the work of Deleuze, Latour, and Haraway, can only push for a “flat” or “horizontal” ontology, for the recognition of “assemblages” that contain and indeed confuse both natural and cultural agents, if matter is “active.”5 It’s precisely in this sense that an
“active” conception of matter entails monism. If matter is imagined other-wise, if it is figured, for example, as a passive surface upon which human culture plays, then our ontology would be bifurcated, with certain elements serving as real actors (human culture) while others (non-human nature) fade into the background.
This essay rejects the terms of this battle. It does so by cultivating an antipathy to the opposition Coole and Frost (among other new material-ists) set up. I side neither with proponents of a dead, passive matter, which divides willful human subjects from inert material objects, nor with those who advocate for a lively, active matter, which discloses a monist cosmos
populated by vibrant, agentic substances. Instead, I want to explore the resources afford by a “plastic” conception of matter—a matter, I’ll argue, that cuts across the aforementioned passive/active divide, as it is conceptual-ized in new materialist thought. In doing so, I celebrate the new material-ists’ challenge to take non-human nature seriously, to treat it as an “agent”
capable of surprising effects and worthy of study. Nevertheless, I break with the new materialism on a key point: I reject its insistence on “flat” or
“horizontal” ontologies, its drive to array actants in assemblages or net-works where nature and culture lose their distinction. The problem with such ontologies is that we end up explaining away, rather than properly explicating, the evident differences between “first nature” (understood as biophysical matter) and “second nature” (understood as the “normative”
realm of discursive practices, social codes, and cultural rituals).6 But, as the philosopher John McDowell (1996) rightly notes, it is a mistake “to for-get that nature includes second nature” (xx). To be clear, explaining how nature includes second nature is no easy task. We must clarify how the first nature of biophysical matter somehow denaturalizes itself, thereby produc-ing a supplementary second nature that is functionally, though not substan-tively, autonomous from its physical ground. Put in more abstract terms: we need to demonstrate how monism not only generates but tolerates internal rifts or antagonisms. My small contribution to this immense task will be to show how the concept of “plasticity” can aid us in imagining a nature that somehow makes room for culture.
Among contemporary thinkers, Catherine Malabou, in her various writings on “plasticity,” best explains the importance of this seemingly innocuous idea. As Malabou (2005) notes, “plasticity” contains within it a conceptual tension:
“Plastic,” as an adjective, means two things: on the one hand, to be “sus-ceptible to changes of form” or malleable (clay is a “plastic” material);
and on the other hand, “having the power to bestow form, the power to mould,” as in the expressions, “plastic surgeon” and “plastic arts.”
(8) Put more simply: to be plastic is to be “at once capable of receiving and of giving form” (8). Even in the relatively abstract terms Malabou employs here, we can see that “plastic” matter shares both passive and active char-acteristics. At times, it behaves like a passive substance, since a plastic thing must be shaped by an exogenous force or will. At other moments, though, it’s closer to active matter, since it not only resists external impositions but also insists on imparting a shape of its own. In other words, plastic matter behaves as an inscriptive surface even as it “punches back.”
Plasticity’s importance for the sort of materialism I’ve advocated above—
a materialism that can accommodate antagonistic first and second natures—
is clearest when we consider a particular example of it at work. For much
of the twentieth century (and even longer as I’ll soon argue), neuroscientists have described the brain as plastic. Here, too, Malabou is great help in teas-ing out the significance of this simple idea. Malabou (2008) explains that the plastic brain isn’t entirely determined by preexisting genetic codes, thereby cutting it off from the shaping influences of experience (5). Nevertheless, the brain is not infinitely malleable in the face of new experience; if this were the case, no single or stable pattern would stick, and the experience “sculpt-ing” it would never be retained long enough to influence future thought.
What Malabou’s distinction make clear, then, is that the concept of plastic-ity wavers between two extremes: a “rigidplastic-ity” that would cut off the brain from the influence of mental and socio-cultural experience (since the men-tal phenomena generated by the nervous system would be predetermined wholly by biological presets) and a “flexibility” that would rob the organ of its own forming capacities (since no pattern would be retained long enough to influence future thought).7 Once again, we can see how Malabou’s con-ception of plasticity troubles the binary between passive and active matter.
On the one hand, the plastic matter of the brain is precisely “inert stuff await[ing] cultural imprint.” Because it is not “rigid,” the brain requires exogenous experiential and cultural inscriptions. On the other hand, the plastic brain sometimes manifests the “active” capacities that resist such inscription. Because it is not “flexible,” the brain only stubbornly yields to imprinting. More importantly, we also can see how the plastic brain sup-ports a materialism of first and second natures. The brain is a natural organ that is open to denaturalization insofar as it is sculpted by culturally medi-ated experience. Nevertheless, thanks to its rigidity, the brain resists com-plete denaturalization. In this respect, it becomes a point where the struggle between first and second nature plays out.
This chapter considers the consequences of this struggle for materialist thought. It breaks into two distinct sections. The first section is historical, and, like Sarah Ellenzweig’s and Charles T. Wolfe’s contributions to this volume, it seeks to complicate the account of seventeenth- and eighteenth-century matter theories passed down in current scholarship. I argue that Descartes himself, along with the Newtonian David Hartley, understood the nervous system as plastic rather than simply passive. By demonstrating that Descartes and Hartley anticipate later, more explicitly “plastic” accounts of the brain in the work of William James and Donald O. Hebb, I uncover a tradition that consistently confounds the distinction between passive and active matter, and, in doing so, makes room for the struggle of first and second natures which interests me.8 The second section considers the work of the contemporary philosopher Adrian Johnston. Although Johnston has engaged with the writings of certain new materialists (most notably Jane Bennett and William Connolly), he rejects their “flat” ontologies in favor of a system that can accommodate the stuff of mind and culture in a material-ist system, without lapsing into the strong dualisms of social constructiv-ism or Cartesian substance ontology. He, too, looks to neuroplasticity as
an empirical support for his views. If plasticity combines both active and passive accounts of matter, then, he explains, we must reckon with the fact that, at moments, the “first nature” of physical matter really does receive imprint from a mindful or cultural “second nature.” Nevertheless, Johnston takes seriously the danger that, in imagining matter as a mere receptacle for cultural or mental contents, we risk installing a dualism that grants sole agency to one side of the divide over the other. The trick, then, is to some-how reconcile a seeming dualism (between matter and mind, nature and culture) with the demands of monism.
We’ll remember that in Coole and Frost’s important introduction, René Descartes serves as the ideal foil for the new materialist’s conception of matter, agency, and ontology. For the aforementioned new materialists, Descartes’ greatest sin isn’t only that he continually describes matter as
“extended, uniform, and inert”; it’s that, in doing so, he summons an incor-poreal presence (the human soul) that possesses the agency which brute, dead, and passive matter otherwise lacks.
At first glance, Descartes’ most thorough account of human physiol-ogy, his Treatise of Man, exemplifies this dynamic. In that work—written in the 1630s but not published until the 1660s—Descartes maintains that the rational soul experiences the external world through ideas carved upon the pineal gland. In my brief summary, it would seem that Descartes treats matter here as entirely passive, since it serves as a medium through which the incorporeal soul experiences the world. Nevertheless, in the follow-ing pages, I’ll complicate this common readfollow-ing of Descartes by pointfollow-ing to aspects of his neurophysiology that cannot be captured by the passive/active dichotomy that appears so frequently in new materialist writing. My goal isn’t to demonstrate that Cartesian neurophysiology is somehow secretly vitalist but rather that it is “plastic”—a term that, as we saw, embraces both active and passive aspects of matter, aspects evident even in this “mechanis-tic” account of mind and body.
Before attending to plasticity, though, it’s worth briefly surveying Descartes’ neurophysiological theories, since, as I mentioned above, they are far more complex than brief accounts usually let on.9 Descartes con-tends that when an external object (e.g., a ray of light) impinges upon the back of the eye, the optic nerve stretching from the eye to the pineal gland will then be pulled and hence enlarged. After this, “animal spirits”—bits of refined, particulate matter which are pushed past the pineal gland thanks to the pumping heart—are impelled into the now widened nerve.10 In doing so, these animal spirits leave a trace upon the pineal gland. The resulting inscription mirrors both the figure in the eye and the external object that set this process in motion. In sum: sensory stimuli actuate the nerves; the nerves open; the animal spirits leave a trace of their fleeting movements upon the pineal as they are pushed into openings. The process is simple but the outcome is immense: the incorporeal soul can interact with the external world from its place within the pineal gland. As Descartes (1972) explains,
the animal spirits’ inscriptions “should be taken to be ideas, that is to say, to be the forms or images that the rational soul will consider directly when … it will imagine or will sense any object” (86).
So far my account of Treatise of Man accords with the new material-ists’ depiction of Cartesian philosophy as a dualist system erected upon the foundation of dead matter. The only entity here that has any real autonomy, after all, is the incorporeal soul, which can imagine or sense the external world as it pleases thanks to the handiwork of the animal spirits. Everything else—that is to say everything material—persists in an implacable circuit of cause and effect. But this only tells half the story. Things become more complicated—and the easy distinction between active and passive matter less clear—when Descartes details memory. Remember again how images appear to the mind. Once a certain set of nerves open, animal spirits enter these passages and, as a byproduct, produce an inscription upon the pineal gland—an inscription that the soul will interpret as an image or idea. When the spirits first rush past the pineal gland into enlarged nerves, they do so with some difficulty. Over time, however, the spirits “are forceful enough to enlarge these intervals [in the nerves] somewhat and to bend and rear-range any filaments they encounter” (Descartes 1972, 88). The animal spir-its’ ability to enter particular passages in the brain becomes “increasingly effective in … that their action is stronger, or lasts longer, or is more often repeated” (88). In effect, certain nerves “remain open even” in the absence of the external objects. Hence, the animal spirits’ steady loosening of these openings allows us to retain memories.
However, if certain nerves are more likely to open, or remain open, thanks to repeated use, then corresponding images will appear before the mind, even though there is no external force actuating this process. In the case of memory, matter dictates the appearance of mental images. For example, Descartes (1972) explains that, at times, the enlargement of par-ticular sets of nerves will impose an image on the mind “as if by chance and without the memory of them being excited by an object impinging on the senses” (96). Even those memories the mind actively seeks out have an involuntary nature to them thanks to the disposition of the nerves and the mechanisms of mental association. “[T]he recollection of one thing can be excited by that of another which was imprinted in the memory at the same time. For example, if I see two eyes with a nose, I at once imagine a forehead and a mouth and all the other parts of a face” (90). This happens because the nerves that correspond to the images of “eyes” and “nose” (call them
“a” and “b”) often open with the nerves corresponding to “forehead” and
“mouth”(“c” and “d”): “if one were merely to reopen some [nerves], like a and b, that fact alone could cause others like c and d to reopen at the very same time, especially if they all had been opened several times together and had not customarily been opened separately” (90). In other words, because a particular sequence of nerves habitually opens together, we have no choice but to recall certain strings of associated mental images. In this instance,
matter, rather than mind, dictates the course of our thoughts. In extreme instances, the brain can even make us see images that have no real-world counterpart. Curiously Descartes attributes the creation of such images not to the creative genius of the incorporeal soul but to the random flux of mat-ter. If two sensory images “are traced in this same region of the brain almost equally perfectly … the spirits will acquire a [combined] impression of them all. … It is thus that chimeras and hypogryphs [sic] are formed in the imagi-nations of those who daydream, that is to say who let their fancy wander listlessly here and there without external objects diverting it and without the fancy’s being directed by reason” (96).
In Descartes’ account of memory (involuntary, associative, and wholly imagined) we encounter “active” matter (in the new materialists’ sense).
Remember that, for the new materialist, matter doesn’t need to be conven-tionally living or organic to be considered “lively.” Inorganic matter (such as atoms) and even inanimate artifacts (such as trash) can be considered
“active” so long as it is “self-creative, productive, unpredictable,” so long as it manifests “agentic capacities [that produce] a domain of unintended and unanticipated effects” (Coole and Frost 2010, 9, 10). And once the nerve fib-ers in the Cartesian brain begin to open of their own accord—thereby gener-ating involuntary associative memories or even wholly fantastic images—we are dealing with active, agentic matter. We witness matter’s productive and creative potential in the brain’s ability to produce chimeras from received sense experience. Likewise, matter’s capacity to give rise to “unpredicta-ble,” “unintended and unanticipated effects”—effects that, in other words, defy the mind’s control—is evident in its associative mechanisms. In this instance—a reversal of the clear priority Descartes affords the incorporeal, rational soul—matter directs thought; the soul cannot help but view a cer-tain string of images because the nerves drive the order of these imaginings.
It will be disputed that what I’m calling “active” matter—nerves that open of their own accord and thereby determine thought—is only active because at one point it was passive. That is, the nerves were made active by the recurrence of sensory stimuli; they manifest “agentic capacities” only because they were, at one point, capable of being molded and enlarged by external forces. But this objection nicely illustrates my larger point. If even in the Cartesian account of the brain, a supposed exemplar of the dualism the new materialists inveigh against, we can locate both passive, imprinted matter and active, agentic substance, then we require a more capacious account of material things. I’ve argued that “plastic” matter, and in par-ticular neuro-plastic matter, serves as an ideal alternative, since the plastic has the ability to take on form passively (i.e., it can serve as a receptacle for exogenous experience) and give form actively (i.e., it can shape and direct thought). To be sure, with Descartes’ Treatise of Man, we are far off from contemporary accounts of neuroplasticity. Nevertheless, we can discern the outlines of more modern accounts of neuroplasticity in Descartes’ work.
Descartes makes it clear that, in the plastic brain, passivity and activity
are simply two moments in a process. At first, brain matter is passive; it is molded by an external agent, like certain nerves opening due to sensory stimulus. Over time, however, the mere repetition of this process grants matter habits and dispositions; certain sets of nerves are more likely to open together, as they have in the past. Finally, passive matter, endowed with a kind of memory, shades into an active agent; we cannot help but imagine an entire face, even when we think only of a set of eyes, since our brain forces such images upon us. As Sarah Ellenzweig explains in her more thor-ough examination of seventeenth- and eighteenth-century matter theories in this volume, for thinkers like Descartes “matter exists along a continuum of relative activity and passivity” (4). And, in fact, we’ll see this dynamic repeated in a host of thinkers, though the precise mechanisms of matter will be different in each case. Passivity passes into activity thanks to time, repeti-tion, and memory.
Published about a hundred years after the appearance of Descartes’
Treatise of Man, David Hartley’s Observations on Man makes this plas-tic dynamic even starker by significantly expanding upon the Cartesian account of memory and mental association. Moreover, Hartley considers something neglected by Descartes: the manner in which culture or “second nature” shapes and molds the brain. For Hartley, as for Descartes, it is in the nature of brain matter to associate or link together certain trains of thought. In other words, for Hartley, the brain doesn’t only receive form from the external world, it also actively works on those received forms and imposes new form in turn on the mind. Additionally, Hartley emphasizes that the forms we receive from the external world are mediated by culture and social institutions.
Hartley attributes the brain’s associative abilities to certain (active) capacities in matter first delineated by Newton. Although Coole and Frost portray Newtonian matter as essentially “predictable, controllable, and rep-licable,” answerable to simple laws of cause and effect, Hartley (1749)—
drawing in particular on Newton’s theory of a “subtle and elastic Fluid”
which pervades both “the Pores of gross Bodies” and “the open Spaces that are void of gross Matter”—argues that matter, thanks precisely to its
“aetheric” qualities, possesses powers it otherwise would lack in a more clockwork world (13). “[T]he Attractions of Gravitation and Cohesion, the Attractions and Repulsions of electrical Bodies, the mutual Influences of Bodies and Light upon each other, the Effects and Communication of Heat, and the Performance of animal Sensation and Motion”—all are thanks to Newton’s “aether” (13). Hartley’s elastic, pulsing, electrical substance serves as another example of the general tendency, delineated by Charles T.
Wolfe in this volume, for matter theories in the eighteenth century to take
“an increasing diversity and density of properties” (5).
The importance of these “aetheric” qualities are particularly evident when Hartley explains how ideas are retained in the brain. Unlike Descartes, who imagines that experience is literally carved onto the brain by animal
spirits rushing out of the pineal gland, Hartley contends that ideas are sim-ply patterns of vibration captured in cerebral substance. As Hartley (1749) notes, “when external Objects are impressed on the sensory Nerves, they excite Vibrations in the Aether residing in the Pores of these Nerves, by means of the mutual Actions interceding between the Objects, Nerves, and Aether” (21). While the resulting vibration eventually vanishes, a continual repetition of certain sense-impressions (and resulting vibrations) can take on “a more permanent Nature” (57). In other words, the substance of the brain, once it has been vibrating a certain way long enough, will reproduce and reinforce that vibratory state.
But such vibrations never reproduce the external world perfectly.
Vibrations “diffuse” into those parts of the brain where they don’t belong.
Vibrations, in other words, are always spilling out of their designated places, running out of their proper tracks, and combining within the folds of the brain in order to produce novel associations and even create new thoughts.
This happens, according to Hartley, simply because repetition eventually leads to new mental dispositions:
Since the Vibrations A and B are impressed together, they must, from the Diffusion necessary to vibratory Motions, run into one Vibration;
and consequently, after a Number of Impressions sufficiently repeated, will leave a Trace, or Miniature, of themselves, as one Vibration, which will recur every now-and-then, from slight Causes.
(70) In Hartley’s system, then, we witness another instance of the same plastic process we encountered in Descartes. A “passive” brain becomes “active”
through the repeated imposition of exogenous stimuli. The brain passively receives external stimuli, but in doing so it actively reworks those stimuli, forging new ideas and trains of thought in the process. Once enough vibra-tions have joined themselves together in the mind, one cannot help but fol-low certain trains of thought or see complex ideas where simpler ones once stood distinct. While for Descartes matter’s ability to lead along the mind often seemed like a danger, for Hartley we simply wouldn’t have complex ideational lives if vibrations didn’t actively link together and determine thought.
Hartley adds something else to the plastic dynamic Descartes describes.
Whereas Descartes concentrated on simple sensory stimuli (e.g., light impinging upon the optic nerves) in his account of neurophysiology, Hartley considers the impact of more complicated and abstract cultural forms on the brain’s physical nature. Hartley’s Observations begins by focusing on the neurophysiology of sensation, memory, and association. But by its con-clusion, the scope of the Observations has widened, with Hartley tackling language, art, morality, politics, and theology. Along the way, Hartley sur-veys the mechanisms by which cultural objects (e.g., art, poetry, philosophy)