Purpose and Desire Read online

  It is also not taught, it must be said, because it is inconvenient to the narrative with which modern biology prinks itself—as a science that has painstakingly climbed up from the vitalist darkness and into the rationalist light. The conventional narrative about Bernard fits this pretense very nicely, which, as these things often go, elevates the simple narrative above the complicated truth. And it is inconvenient for the same reasons a distinguished family might try to cover up the horse-thieving ancestor who established the family fortune: most of modern biology actually finds its roots in the supposedly disreputable vitalist thinking of the nineteenth century, including—most inconveniently of all—Darwin’s evolutionary thought.

  The modern sciences of life cannot be properly understood without an appreciation of this vitalist core. Shoving it into the shadows, as we commonly do today, therefore amounts essentially to a form of narcissistic preening; we are blinded to the world around us in favor of the pretty baubles of mechanism we have adorned ourselves with. Don’t take my word for it: try mentioning vitalism to a room of biologists today and you will usually be met with polite indifference, or a troubled darting of eyes.

  Vitalism poses two basic questions. We already chewed these over in the Preface, but they are worth repeating: is life a special phenomenon, unlike any other in the universe, and if so, what makes it so? If your answer to the first question is “clearly yes,” you are a vitalist, whether you want to admit it or not. The rub comes with how the second question—what makes it so?—is answered.

  Traditionally, that answer took the form of what we may call essentialism: life is special because it is imbued with a special vital essence, or vis essentialis. Life exists because this vis essentialis infuses and animates otherwise inanimate matter. This notion is venerable to the point of being hoary. It predates the Hippocratic physicians, whose medical philosophy derived from the still more ancient doctrine of humors: systems of opposing forces, like the lightness of air versus the heaviness of earth, or the heat of fire versus the cold of water. Life, in this view, was a state of perfect harmony suspended in a matrix of diametrically opposed forces, with the balance mediated by the vis essentialis. To the Hippocratic physicians, health was a state of balance and harmony. Sickness, disease, and death were states of imbalance and disharmony.7

  This doctrine was the theoretical core of medical practice well into the eighteenth century. Therapeutic bloodletting (“bleeding” a patient) provides an interesting example of this philosophy translated into practice.* Traditionally, therapeutic bloodletting was justified by the need to release from the patient an excess of one vital humor that was out of balance with another. Release the excess humor, and the balance of humors would be restored, as would be the patient to a state of health. The practice, indeed so much of medical practice in those times, probably killed more patients than it helped, but never mind, it was justified by sound and venerable teaching—the science was settled, we might say today.*8

  By the eighteenth century, vitalism, and the medical practices it engendered, had become the subject of vigorous debate between competing European schools of academic medicine.9 What emerged from this debate was a radical transformation of vitalist thought from an “essentialist” vitalism (sometimes called “metaphysical vitalism”) to a “process” vitalism (also called “physical vitalism” or “scientific vitalism”).10 Through this subtle shift in perspective, vitalist thought came to be more concerned with action and mechanism than with some ineffable “vital stuff.” In this way, the seeds were planted for metaphysical vitalism’s eventual rout in the nineteenth century.

  Initially, the newly emerging process vitalism drew deeply from its essentialist roots, taking as its inspiration another vital essence, the vis mediatrix, or mediating essence. This vital substance was cooked up as a means of explaining how the actions of the body’s various parts could be coordinated. It was thought to be dispersed through the nerves and would link, or mediate the interactions between, one body part, say the heart, and another, say the stomach. Despite its theoretical utility, vis mediatrix proved to be the poison pill for essentialist vitalism. In keeping with the rising tide of Enlightenment skepticism and the willingness to resort to the authority of empirical proof over that of venerable tradition, the hypothesis of the vis mediatrix opened up a process-oriented outlook toward medicine that proved more congenial to posing experimental questions. The whole doctrine of vital essences could not stand up long under such scrutiny. Vis essentialis was the first to go: physicians could offer only the fact of the living body as evidence of its existence, or a corpse as evidence of its absence. In short, vis essentialis died because it was a scientific dead end.

  That did not entirely kill the idea of vital essences, though. Once vis essentialis was out the door, new essences were cooked up to replace it, because the scientific consensus was that there simply had to be vital essences.11 The vis mediatrix was one of many designated hitters brought in to fill the roster. But these couldn’t stand long either, for the same reasons that did in vis essentialis: they were slippery ad hoc concepts rather than real things you could hold in your hand or collect in bottles.

  Nevertheless, a new spirit of skeptical and evidence-based scrutiny of nature was wafting through European medicine. Much of this nascent empiricism was anatomical and observational. One can find in writings from those times catalogues of correlations between certain diseases and modifications of the body’s organs, for example. All well and good, but there was little in the way of a radical challenge to the prevalent essentialist thinking. Some of those observations, though, were experiments that called into question the very existence of the mediating “stuff.” Why, for example, could an organ, like a frog’s heart, survive for a time outside the body, removed from the influence of any supposed vis mediatrix, and still be responsive to changes in its environment? Why, if the nerves were the conduits for the vis mediatrix, could some organs, like the pancreas, function even though the organ had no discernible innervation?* What is important here is the empirical and skeptical mindset of these early process vitalists, in which contrarian phenomena, such as the disembodied frog heart, were not simply anomalies to be explained away by cooking up another vital essence, but were disproof of a long-standing doctrine.

  Among the most interesting of these contrary observations came from Théophile de Bordeu (Figure 3.1) of the medical college at Montpellier in southern France. Montpellier was one of three medical colleges that drove the transformation of vitalist thought in the eighteenth and nineteenth centuries.* In a remarkable eighteenth-century anticipation of the superorganism idea,* Bordeu drew a parallel between the coordinated behavior of a swarm of bees and a living body. If bees in a swarm were separate bodies, physically disconnected from one another, how could any putative vis mediatrix flow between them? And if there was no vis mediatrix, how were the behaviors of the individuals mediated to produce the hive’s “organism-like” behavior? Bordeu’s little thought experiment not only called into question the very idea of a vis mediatrix, it opened the door to a new and powerful metaphor for understanding life, its function and dysfunction—and as we shall see, its evolution. This was the metaphor of life as an assemblage of “many little lives,” of organisms as collections of semiautonomous units that, through a process of negotiation and mutual accommodation, produced the coherent organism. This was a new way to think about the vital organism. It was not the “stuff”—the vital essence—that formed the organism, but the process—the negotiation and mutual accommodation of the organism’s “many little lives.”

  Figure 3.1

  Théophile de Bordeu (1722–1776).

  Thus was the stage set in 1834, when Claude Bernard went to Paris as a young man, eventually to be drawn into the orbit of the remarkable François Magendie (Figure 3.2). Magendie is important to our story for a number of reasons. He was a caustic critic of essentialist vitalism; he was a flamboyant empiricist and rationalist of the highest order; he became Bernard’s m
entor and collaborator; and he plowed the ground that Bernard later sowed so fruitfully.12

  François was the scion of a prickly revolutionary family. His father, Antoine, was a “barber-surgeon,” practicing at a time when physicians held that profession in some disrepute. As is often the case with upstart professionals fighting for legitimacy and respect, Antoine was aggressively antiaristocratic, anticlerical, skeptical, and rational. When the revolution came, Antoine relocated his family, including the nine-year-old François, to Paris, so he could be in the thick of the upheaval. Eventually, Antoine became disillusioned with practicing surgery (not surprising in light of the horrific suffering inflicted on surgical patients in those preanesthetic days).* So he quit his profession to serve the new republic, which proved to be an impecunious decision. Despite his disillusion with his erstwhile career, Antoine determined that his son should not follow in his father’s folly and instead should seek a career in medicine as his father had. Unfortunately, Antoine had raised his children in such a way that the young François was woefully unprepared for admission to the prestigious École de Santé where his father had wanted him to go.* Antoine’s connections among his former physician colleagues came to the rescue, though, and François was taken on as an apprentice to Alexis Boyer, a prominent French barber-surgeon who, like Antoine, had also risen from humble roots. Under Boyer’s supervision, François flourished and within a year had passed the examinations qualifying him to become a hospital intern. Four years after that, he entered the medical school of the Hôpital Saint-Louis. There, he distinguished himself as a skilled anatomist with a lively—some said prickly—mind. In addition to studying medicine, Magendie was asked to give courses in anatomy and physiology at the École de Médecine. Once he received his medical degree in 1808, Magendie’s path to a stellar career in medicine seemed to be set.

  Figure 3.2

  François Magendie (left, 1783–1855) and Claude Bernard (right, 1813–1878).

  What followed was an erratic career of brilliant success interspersed with controversy and dissipation. Although Magendie quickly had realized his father’s aspirations that he become a physician, and had established himself as a teacher of exceptional skill and accomplishment, he had difficulty sustaining a medical practice because he was denied an appointment as a hospital physician and blocked by senior colleagues who regarded him as a dangerous rival. Magendie was not his own best friend here: he fell into acrimonious disputes with colleagues within France and across Europe and the British Isles. He became the beneficiary of an inheritance only to squander it on horses, parties, and drink. For a time, he offered public dissections and vivisections for a fee. His demonstrations commanded high prices, because of Magendie’s extraordinary surgical skills, his showmanship, and his willingness to make himself the subject of some of his demonstrations. Being shut out of medical practice, he turned his considerable energy and curiosity to medical research, bouncing from one appointment to another in the Paris medical scene. He made remarkable discoveries in the function of the brain. Ultimately, even his enemies could not hold this brash man back: he was eventually elected to the Académie des Sciences and to the Académie Royale de Médecine (“in spite of myself,” in Magendie’s own ironic words).

  Magendie’s erratic, critical, and abrasive personality and his energy, bluntness, and irritation with received wisdom grabbed French medicine by the collar. The particular target of his scorn was the essentialist idea, and at the time of Magendie’s rising fame, it was starting to gasp its last, propelled there in no small part by Magendie’s pointed attacks on the endless proliferation of “vital forces” that academic physicians were wont to invoke whenever an unexpected phenomenon cropped up:

  Why then is it necessary in respect to every phenomenon of the living body to invent a peculiar and special vital force? Cannot one be content with a single force which one could designate “vital force” in a general way, while admitting that it gives rise to different phenomena depending upon the structure of the organs and tissues which function under its influence? But is not this single vital force still too much? Is it not an hypothesis pure and simple, inasmuch as we are unable to perceive it?

  Magendie was more than capable of delivering this criticism in the bluntest of terms:

  To express an opinion [on the existence of a vital force], to believe, is nothing else than to be ignorant. . . . One could with justice say to you “You believe, therefore you don’t know.”13

  One can easily imagine the attraction the brash Magendie must have had for the young Bernard, in from the provinces and looking to make his mark.

  Bernard’s upbringing was more conservative than Magendie’s. His father, Pierre-François, was a provincial winemaker and petit land-owner in Beaujolais, and so he was not as caught up in revolutionary fervor as was Antoine Magendie. Claude Bernard’s early education was mostly in local Jesuit schools. These bored him immensely, but he had an active and curious mind, so he became an autodidact, indulging a growing interest in philosophy and the romantic arts. One had to make a living, though, so when a school friend enthused about his new career in pharmacy, Claude decided to follow his friend and become a pharmacist’s apprentice himself. This proved not to be as happy an experience as he had hoped, so Claude surreptitiously began to plot his escape to Paris, to follow there his dream of becoming a playwright. The plot ripened prematurely when, in the aftermath of an accident at the apothecary, Claude’s pharmacist master discovered that Claude had been working on a play rather than attending to potions. He was duly shown the door. Seizing the opportunity, off to Paris he went.

  Once there, Bernard’s artistic aspirations quickly foundered at the hands of the critic Saint-Marc Girardin, who kindly, but firmly, advised Bernard that he should perhaps try his hand at medicine instead. Wisely, Bernard took this advice (thank you, Girardin!), and after some difficulty with the entrance examinations, he enrolled in medical school. To support himself, Bernard took on work as a laboratory assistant in a Parisian girls’ school, where he proved to be extraordinarily skillful in dissection. Bernard’s anatomical prowess soon captured the attention of Magendie, who took him on as preparateur for his lectures at the Collège de France. Soon thereafter, Bernard formally became Magendie’s student, setting him firmly on his own path to a scientific career.

  Bernard’s relationship with the mercurial Magendie was both contrary and complementary. It was stormy, marked by intermittent fallings-out and reconciliations. Like Magendie, Bernard brought to his work a healthy dose of skepticism, seeded in this case by his recollection of the slapdash pharmaceutical formulations (which sometimes included the leavings of other potions) that he had been ordered to make during his apprenticeship, and by the utter lack of rationale or evidence for their effectiveness. Bernard’s career was as mercurial as Magendie’s. Like Magendie, he had difficulty as a practicing physician, although unlike Magendie, Bernard never felt compelled to practice medicine, preferring research. He left Paris to return to his home village to establish a country practice there, but his heart wasn’t in it. His marriage to the wealthy Fanny Martin gave him the freedom to pursue his research interests, but the freedom was bought at a terrific price of an unhappy marriage and the premature deaths of all three of their children. Like Magendie, his brilliance as an experimentalist and teacher propelled his eventual rise to the top of French science. He was made a Chevalier of the Légion d’Honneur; he obtained a doctorate in zoology to bolster his research credentials; and he was eventually appointed to a special chair at the Faculty of Sciences in Paris, was elected to the Académie des Sciences and the Académie de Médecine, and took over Magendie’s chair of medicine after Magendie died.

  Bernard was attracted to Magendie’s thoroughgoing skepticism and his willingness to challenge conventional wisdom. Bernard’s skepticism was rooted in more conservative soil than Magendie’s, though. While Magendie’s radical skepticism bolstered Bernard’s own, Bernard parted company with his mentor in some significant
ways, the most significant being over the nature of life. Magendie was a radical materialist, prepared to fold life fully into the nascent field of chemistry. Bernard was not quite prepared to go so far, though, which is captured in his aphorism: the stability of the milieu intérieur is the antecedent to, not the outcome of, the free and independent life. An understanding of the chemical workings of life would enable physiologists to meet their prime scientific obligation: to make the workings of life’s antecedent intelligible. But physiologists could never forget that it is the antecedent, life’s unique nature, that is life’s principal “fact on the ground.” Bernard expressed it this way:

  Since physicists and chemists cannot take their stand outside the universe, they study bodies and phenomena in themselves and separately without necessarily having to connect them with nature as a whole. But physiologists, finding themselves, on the contrary, outside the animal organism which they see as a whole, must take account of the harmony of this whole, even while trying to get inside, so as to understand the mechanism of its every part. The result is that physicists and chemists can reject all idea of final causes for the facts that they observe; while physiologists are inclined to acknowledge an harmonious and pre-established unity in an organized body, all of whose partial actions are interdependent and mutually generative [emphasis mine].14

  Here we see the elements of nineteenth-century process vitalism—the notion of the organism as a harmonious whole comprising “many little lives,” along with the emphasis on teasing out the processes of mutual accommodation that undergirded the principal “fact on the ground”: the integrated, coherent, and harmonious organism.