The Mental LIfe Of Plants

 

The Mental Life of Plants and Worms, Among Others
Oliver Sacks

April 24, 2014 Issue
The Formation of Vegetable Mould through the Action of Worms: with Observations on Their Habits
by Charles Darwin
London: John Murray (1881)

Charles Darwin’s last book, published in 1881, was a study of the humble earthworm. His main theme—expressed in the title, The Formation of Vegetable Mould through the Action of Worms—was the immense power of worms, in vast numbers and over millions of years, to till the soil and change the face of the earth. But his opening chapters are devoted more simply to the “habits” of worms.
Worms can distinguish between light and dark, and they generally stay underground, safe from predators, during daylight hours. They have no ears, but if they are deaf to aerial vibration, they are exceedingly sensitive to vibrations conducted through the earth, as might be generated by the footsteps of approaching animals. All of these sensations, Darwin noted, are transmitted to collections of nerve cells (he called them “the cerebral ganglia”) in the worm’s head.
When a worm is suddenly illuminated,” Darwin wrote, it “dashes like a rabbit into its burrow.” He noted that he was “at first led to look at the action as a reflex one,” but then observed that this behavior could be modified—for instance, when a worm was otherwise engaged, it showed no withdrawal with sudden exposure to light.
For Darwin, the ability to modulate responses indicated “the presence of a mind of some kind.” He also wrote of the “mental qualities” of worms in relation to their plugging up their burrows, noting that “if worms are able to judge…having drawn an object close to the mouths of their burrows, how best to drag it in, they must acquire some notion of its general shape.” This moved him to argue that worms “deserve to be called intelligent, for they then act in nearly the same manner as a man under similar circumstances.”
As a boy, I played with the earthworms in our garden (and later used them in research projects), but my true love was for the seashore, and especially tidal pools, for we nearly always took our summer holidays at the seaside. This early, lyrical feeling for the beauty of simple sea creatures became more scientific under the influence of a biology teacher at school and our annual visits with him to the Marine Station at Millport in southwest Scotland, where we could investigate the immense range of invertebrate animals on the seashores of Cumbrae. I was so excited by these Millport visits that I thought I would like to become a marine biologist myself.
f Darwin’s book on earthworms was a favorite of mine, so too was George John Romanes’s 1885 book Jelly-Fish, Star-Fish, and Sea-Urchins: Being a Research on Primitive Nervous Systems, with its simple, fascinating experiments and beautiful illustrations. For Romanes, Darwin’s young friend and student, the seashore and its fauna were to be passionate and lifelong interests, and his aim above all was to investigate what he regarded as the behavioral manifestations of “mind” in these creatures.
I was charmed by Romanes’s personal style. (His studies of invertebrate minds and nervous systems were most happily pursued, he wrote, in “a laboratory set up upon the sea-beach…a neat little wooden workshop thrown open to the sea-breezes.”) But it was clear that correlating the neural and the behavioral was at the heart of Romanes’s enterprise. He spoke of his work as “comparative psychology,” and saw it as analogous to comparative anatomy.
Louis Agassiz had shown, as early as 1850, that the jellyfish Bougainvillea had a substantial nervous system, and by 1883 Romanes demonstrated its individual nerve cells (there are about a thousand). By simple experiments—cutting certain nerves, making incisions in the bell, or looking at isolated slices of tissue—he showed that jellyfish employed both autonomous, local mechanisms (dependent on nerve “nets”) and centrally coordinated activities through the circular “brain” that ran along the margins of the bell.
By 1883, Romanes was able to include drawings of individual nerve cells and clusters of nerve cells, or ganglia, in his book Mental Evolution in Animals. “Throughout the animal kingdom,” Romanes wrote,
nerve tissue is invariably present in all species whose zoological position is not below that of the Hydrozoa. The lowest animals in which it has hitherto been detected are the Medusae, or jelly-fishes, and from them upwards its occurrence is, as I have said, invariable. Wherever it does occur its fundamental structure is very much the same, so that whether we meet with nerve-tissue in a jelly-fish, an oyster, an insect, a bird, or a man, we have no difficulty in recognizing its structural units as everywhere more or less similar.
At the same time that Romanes was vivisecting jellyfish and starfish in his seaside laboratory, the young Sigmund Freud, already a passionate Darwinian, was working in the lab of Ernst Brücke, a physiologist in Vienna. His special concern was to compare the nerve cells of vertebrates and invertebrates, in particular those of a very primitive vertebrate (Petromyzon, a lamprey) with those of an invertebrate (a crayfish). While it was widely held at the time that the nerve elements in invertebrate nervous systems were radically different from those of vertebrate ones, Freud was able to show and illustrate, in meticulous, beautiful drawings, that the nerve cells in crayfish were basically similar to those of lampreys—or human beings.
And he grasped, as no one had before, that the nerve cell body and its processes—dendrites and axons—constituted the basic building blocks and the signaling units of the nervous system. Eric Kandel, in his book In Search of Memory: The Emergence of a New Science of Mind (2006), speculates that if Freud had stayed in basic research instead of going into medicine, perhaps he would be known today as “a co-founder of the neuron doctrine, instead of as the father of psychoanalysis.”
Although neurons may differ in shape and size, they are essentially the same from the most primitive animal life to the most advanced. It is their number and organization that differ: we have a hundred billion nerve cells, while a jellyfish has a thousand. But their status as cells capable of rapid and repetitive firing is essentially the same.
The crucial role of synapses—the junctions between neurons where nerve impulses can be modulated, giving organisms flexibility and a whole range of behaviors—was clarified only at the close of the nineteenth century by the great Spanish anatomist Santiago Ramón y Cajal, who looked at the nervous systems of many vertebrates and invertebrates, and by C.S. Sherrington in England (it was Sherrington who coined the word “synapse” and showed that synapses could be excitatory or inhibitory in function).
In the 1880s, however, despite Agassiz’s and Romanes’s work, there was still a general feeling that jellyfish were little more than passively floating masses of tentacles ready to sting and ingest whatever came their way, little more than a sort of floating marine sundew.
But jellyfish are hardly passive. They pulsate rhythmically, contracting every part of their bell simultaneously, and this requires a central pacemaker system that sets off each pulse. Jellyfish can change direction and depth, and many have a “fishing” behavior that involves turning upside down for a minute, spreading their tentacles like a net, and then righting themselves, which they do by virtue of eight gravity-sensing balance organs. (If these are removed, the jellyfish is disoriented and can no longer control its position in the water.) If bitten by a fish, or otherwise threatened, jellyfish have an escape strategy—a series of rapid, powerful pulsations of the bell—that shoots them out of harm’s way; special, oversized (and therefore rapidly responding) neurons are activated at such times.
Of special interest and infamous reputation among divers is the box jellyfish (Cubomedusae)—one of the most primitive animals to have fully developed image-forming eyes, not so different from our own. The biologist Tim Flannery, in an article in these pages, writes of box jellyfish:
They are active hunters of medium-sized fish and crustaceans, and can move at up to twenty-one feet per minute. They are also the only jellyfish with eyes that are quite sophisticated, containing retinas, corneas, and lenses. And they have brains, which are capable of learning, memory, and guiding complex behaviors.
We and all higher animals are bilaterally symmetrical, have a front end (a head) containing a brain, and a preferred direction of movement (forward). The jellyfish nervous system, like the animal itself, is radially symmetrical and may seem less sophisticated than a mammalian brain, but it has every right to be considered a brain, generating, as it does, complex adaptive behaviors and coordinating all the animal’s sensory and motor mechanisms. Whether we can speak of a “mind” here (as Darwin does in regard to earthworms) depends on how one defines “mind.”
We all distinguish between plants and animals. We understand that plants, in general, are immobile, rooted in the ground; they spread their green leaves to the heavens and feed on sunlight and soil. We understand that animals, in contrast, are mobile, moving from place to place, foraging or hunting for food; they have easily recognized behaviors of various sorts. Plants and animals have evolved along two profoundly different paths (fungi have yet another), and they are wholly different in their forms and modes of life.
And yet, Darwin insisted, they were closer than one might think. He wrote a series of botanical books, culminating in The Power of Movement in Plants (1880), just before his book on earthworms. He thought the powers of movement, and especially of detecting and catching prey, in the insectivorous plants so remarkable that, in a letter to the botanist Asa Gray, he referred to Drosera, the sundew, only half-jokingly as not only a wonderful plant but “a most sagacious animal.”
Darwin was reinforced in this notion by the demonstration that insect-eating plants made use of electrical currents to move, just as animals did—that there was “plant electricity” as well as “animal electricity.” But “plant electricity” moves slowly, roughly an inch a second, as one can see by watching the leaflets of the sensitive plant (Mimosa pudica) closing one by one along a leaf that is touched. “Animal electricity,” conducted by nerves, moves roughly a thousand times faster.2
Signaling between cells depends on electrochemical changes, the flow of electrically charged atoms (ions), in and out of cells via special, highly selective molecular pores or “channels.” These ion flows cause electrical currents, impulses—action potentials—that are transmitted (directly or indirectly) from one cell to another, in both plants and animals.
Plants depend largely on calcium ion channels, which suit their relatively slow lives perfectly. As Daniel Chamovitz argues in his book What a Plant Knows (2012), plants are capable of registering what we would call sights, sounds, tactile signals, and much more. Plants know what to do, and they “remember.” But without neurons, plants do not learn in the same way that animals do; instead they rely on a vast arsenal of different chemicals and what Darwin termed “devices.” The blueprints for these must all be encoded in the plant’s genome, and indeed plant genomes are often larger than our own.
The calcium ion channels that plants rely on do not support rapid or repetitive signaling between cells; once a plant action potential is generated, it cannot be repeated at a fast enough rate to allow, for example, the speed with which a worm “dashes…into its burrow.” Speed requires ions and ion channels that can open and close in a matter of milliseconds, allowing hundreds of action potentials to be generated in a second. The magic ions, here, are sodium and potassium ions, which enabled the development of rapidly reacting muscle cells, nerve cells, and neuromodulation at synapses. These made possible organisms that could learn, profit by experience, judge, act, and finally think.
This new form of life—animal life—emerging perhaps 600 million years ago conferred great advantages, and transformed populations rapidly. In the so-called Cambrian explosion (datable with remarkable precision to 542 million years ago), a dozen or more new phyla, each with very different body plans, arose within the space of a million years or less—a geological eye-blink. The once peaceful pre-Cambrian seas were transformed into a jungle of hunters and hunted, newly mobile. And while some animals (like sponges) lost their nerve cells and regressed to a vegetative life, others, especially predators, evolved increasingly sophisticated sense organs, memories, and minds.
It is fascinating to think of Darwin, Romanes, and other biologists of their time searching for “mind,” “mental processes,” “intelligence,” even “consciousness” in primitive animals like jellyfish, and even in protozoa. A few decades afterward, radical behaviorism would come to dominate the scene, denying reality to what was not objectively demonstrable, denying in particular any inner processes between stimulus and response, deeming these as irrelevant or at least beyond the reach of scientific study.
Such a restriction or reduction indeed facilitated studies of stimulation and response, both with and without “conditioning,” and it was Pavlov’s famous studies of dogs that formalized—as “sensitization” and “habituation”—what Darwin had observed in his worms.
As Konrad Lorenz wrote in The Foundations of Ethology, “an earthworm [that] has just avoided being eaten by a blackbird…is indeed well-advised to respond with a considerably lowered threshold to similar stimuli, because it is almost certain that the bird will still be nearby for the next few seconds.” This lowering of threshold, or sensitization, is an elementary form of learning, even though it is nonassociative and relatively short-lived. Correspondingly, a diminution of response, or habituation, occurs when there is a repeated but insignificant stimulus—something to be ignored.
It was shown within a few years of Darwin’s death that even single-cell organisms like protozoa could exhibit a range of adaptive responses. In particular, Herbert Spencer Jennings showed that the tiny, stalked, trumpet-shaped unicellular organism Stentor employs a repertoire of at least five different responses to being touched, before finally detaching itself to find a new site if these basic responses are ineffective. But if it is touched again, it will skip the intermediate steps and immediately take off for another site. It has become sensitized to noxious stimuli, or, to use more familiar terms, it “remembers” its unpleasant experience and has learned from it (though the memory lasts only a few minutes). If, conversely, Stentor is exposed to a series of very gentle touches, it soon ceases to respond to these at all—it has habituated.
Jennings described his work with sensitization and habituation in organisms like Paramecium and Stentor in his 1906 book Behavior of the Lower Organisms. Although he was careful to avoid any subjective, mentalistic language in his description of protozoan behaviors, he did include an astonishing chapter at the end of his book on the relation of observable behavior to “mind.”
He felt that we humans are reluctant to attribute any qualities of mind to protozoa because they are so small:
The writer is thoroughly convinced, after long study of the behaviour of this organism, that if Amoeba were a large animal, so as to come in the everyday experience of human beings, its behaviour would at once call forth the attribution to it of states of pleasure and pain, of hunger, desire, and the like, on precisely the same basis as we attribute these things to the dog.
Jennings’s vision of a highly sensitive, dog-size Amoeba is almost cartoonishly the opposite of Descartes’s notion of dogs as so devoid of feelings that one could vivisect them without compunction, taking their cries as purely “reflex” reactions of a quasi-mechanical kind.
Sensitization and habituation are crucial for the survival of all living organisms. These elementary forms of learning are short-lived—a few minutes at most—in protozoa and plants; longer-lived forms require a nervous system.
While behavioral studies flourished, there was almost no attention paid to the cellular basis of behavior—the exact role of nerve cells and their synapses. Investigations in mammals—involving, for example, the hippocampal or memory systems in rats—presented almost insuperable technical difficulties, due to the tiny size and extreme density of neurons (there were difficulties, moreover, even if one could record electrical activity from a single cell, in keeping it alive and fully functioning for the duration of protracted experiments).
Faced with such difficulties in his anatomical studies in the early twentieth century, Ramón y Cajal—the first and greatest microanatomist of the nervous system—had turned to study simpler systems: those of young or fetal animals, and those of invertebrates (insects, crustaceans, cephalopods, etc.). For similar reasons, Eric Kandel, when he embarked in the 1960s on a study of the cellular basis of memory and learning, sought an animal with a simpler and more accessible nervous system. He settled on the giant sea snail Aplysia, which has 20,000 or so neurons, distributed in ten or so ganglia of about 2,000 neurons apiece. It also has particularly large neurons—some even visible to the naked eye—connected with one another in fixed anatomical circuits.
That Aplysia might be considered too low a form of life for studies of memory did not discountenance Kandel, despite some skepticism from his colleagues—any more than it had discountenanced Darwin when he spoke of the “mental qualities” of earthworms. “I was beginning to think like a biologist,” Kandel writes, recalling his decision to work with Aplysia. “I appreciated that all animals have some form of mental life that reflects the architecture of their nervous system.”
As Darwin had looked at an escape reflex in worms and how it might be facilitated or inhibited in different circumstances, Kandel looked at a protective reflex in Aplysia, the withdrawal of its exposed gill to safety, and the modulation of this response. Recording from (and sometimes stimulating) the nerve cells and synapses in the abdominal ganglion that governed these responses, he was able to show that relatively short-term memory and learning—as involved in habituation and sensitization—depended on functional changes in synapses; but longer-term memory, which might last several months, went with structural changes in the synapses. (In neither case was there any change in the actual circuits.)
As new technologies and concepts emerged in the 1970s, Kandel and his colleagues were able to complement these electrophysiological studies of memory and learning with chemical ones: “We wanted to penetrate the molecular biology of a mental process, to know exactly what molecules are responsible for short-term memory.” This entailed, in particular, studies of the ion channels and neurotransmitters involved in synaptic functions—monumental work that earned Kandel a Nobel Prize.
Where Aplysia has only 20,000 neurons distributed in ganglia throughout its body, an insect may have up to a million nerve cells, all concentrated in one brain, and despite its tiny size may be capable of extraordinary cognitive feats. Thus bees are expert in recognizing different colors, smells, and geometric shapes presented in a laboratory setting, as well as systematic transformations of these. And of course, they show superb expertise in the wild or in our gardens, where they recognize not only the patterns and smells and colors of flowers, but can remember their locations and communicate these to their fellow bees.
It has even been shown, in a highly social species of paper wasp, that individuals can learn and recognize the faces of other wasps. Such face learning has hitherto been described only in mammals; it is fascinating that a cognitive power so specific can be present in insects as well.
We often think of insects as tiny automata—robots with everything built-in and programmed. But it is increasingly evident that insects can remember, learn, think, and communicate in quite rich and unexpected ways. Much of this, doubtless, is built-in—but much, too, seems to depend on individual experience.
Whatever the case with insects, there is an altogether different situation with those geniuses among invertebrates, the cephalopods, consisting of octopuses, cuttlefish, and squid. Here, as a start, the nervous system is much larger—an octopus may have half a billion nerve cells distributed between its brain and its “arms” (a mouse, by comparison, has only 75 to 100 million). There is a remarkable degree of organization in the octopus brain, with dozens of functionally distinct lobes in the brain and similarities to the learning and memory systems of mammals.
Cephalopods are not only easily trained to discriminate test shapes and objects, but some reportedly can learn by observation, a power otherwise confined to certain birds and mammals. They have remarkable powers of camouflage, and can signal complex emotions and intentions by changing their skin colors, patterns and textures.
Darwin noted in The Voyage of the Beagle how an octopus in a tidal pool seemed to interact with him, by turns watchful, curious, and even playful. Octopuses can be domesticated to some extent, and their keepers often empathize with them, feeling some sense of mental and emotional proximity. Whether one can use the “C” word—consciousness—in regard to cephalopods can be argued all ways. But if one allows that a dog may have consciousness of an individual and significant sort, one has to allow it for an octopus, too.
Nature has employed at least two very different ways of making a brain—indeed, there are almost as many ways as there are phyla in the animal kingdom. Mind, to varying degrees, has arisen or is embodied in all of these, despite the profound biological gulf that separates them from one other, and us from them.4

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What Is Enlightenment?

http://foucault.info/documents/whatisenlightenment/foucault.whatisenlightenment.en.html
Foucault, Michel. “What is Enlightenment?” In The Foucault Reader, edited by Paul Rabinow, pp. 32-50. New York: Pantheon Books, 1984
What is Enlightenment?

Today when a periodical asks its readers a question, it does so in order to collect opinions on some subject about which everyone has an opinion already; there is not much likelihood of learning anything new. In the eighteenth century, editors preferred to question the public on problems that did not yet have solutions. I don’t know whether or not that practice was more effective; it was unquestionably more entertaining.
In any event, in line with this custom, in November 1784 a German periodical, Berlinische Monatschrift published a response to the question: Was ist Aufklärung? And the respondent was Kant.
A minor text, perhaps. But it seems to me that it marks the discreet entrance into the history of thought of a question that modern philosophy has not been capable of answering, but that it has never managed to get rid of, either. And one that has been repeated in various forms for two centuries now. From Hegel through Nietzsche or Max Weber to Horkheimer or Habermas, hardly any philosophy has failed to confront this same question, directly or indirectly. What, then, is this event that is called the Aufklärung and that has determined, at least in part, what we are, what we think, and what we do today? Let us imagine that the Berlinische Monatschrift still exists and that it is asking its readers the question: What is modern philosophy? Perhaps we could respond with an echo: modern philosophy is the philosophy that is attempting to answer the question raised so imprudently two centuries ago: Was ist Aufklärung?
Let us linger a few moments over Kant’s text. It merits attention for several reasons.
1. To this same question, Moses Mendelssohn had also replied in the same journal, just two months earlier. But Kant had not seen Mendelssohn’s text when he wrote his. To be sure, the encounter of the German philosophical movement with the new development of Jewish culture does not date from this precise moment. Mendelssohn had been at that crossroads for thirty years or so, in company with Lessing. But up to this point it had been a matter of making a place for Jewish culture within German thought — which Lessing had tried to do in Die Juden — or else of identifying problems common to Jewish thought and to German philosophy; this is what Mendelssohn had done in his Phadon; oder, Über die Unsterblichkeit der Seele. With the two texts published in the Berlinische Monatschrift the German Aufklärung and the Jewish Haskala recognize that they belong to the same history; they are seeking to identify the common processes from which they stem. And it is perhaps a way of announcing the acceptance of a common destiny — we now know to what drama that was to lead.
2.  But there is more. In itself and within the Christian tradition, Kant’s text poses a new problem. It was certainly not the first time that philosophical thought had sought to reflect on its own present. But, speaking schematically, we may say that this reflection had until then taken three main forms.

– The present may be represented as belonging to a certain era of the world, distinct from the others through some inherent characteristics, or separated from the others by some dramatic event. Thus, in Plato’s Statesman the interlocutors recognize that they belong to one of those revolutions of the world in which the world is turning backwards, with all the negative consequences that may ensue.

– The present may be interrogated in an attempt to decipher in it the heralding signs of a forthcoming event. Here we have the principle of a kind of historical hermeneutics of which Augustine might provide an example.

– The present may also be analyzed as a point of transition toward the dawning of a new world. That is what Vico describes in the last chapter of La Scienza Nuova; what he sees “today”; is “a complete humanity … spread abroad through all nations, for a few great monarchs rule over this world of peoples”; it is also “Europe … radiant with such humanity that it abounds in all the good things that make for the happiness of human life”1

Now the way Kant poses the question of Aufklärung is entirely different: it is neither a world era to which one belongs, nor an event whose signs are perceived, nor the dawning of an accomplishment. Kant defines Aufklärung in an almost entirely negative way, as an Ausgang, an “exit,” a “way out.” In his other texts on history, Kant occasionally raises questions of origin or defines the internal teleology of a historical process. In the text on Aufklärung, he deals with the question of contemporary reality alone. He is not seeking to understand the present on the basis of a totality or of a future achievement. He is looking for a difference: What difference does today introduce with respect to yesterday?

3.  I shall not go into detail here concerning this text, which is not always very clear despite its brevity. I should simply like to point out three or four features that seem to me important if we are to understand how Kant raised the philosophical question of the present day.

Kant indicates right away that the “way out” that characterizes Enlightenment is a process that releases us from the status of “immaturity.” And by “immaturity,” he means a certain state of our will that makes us accept someone else’s authority to lead us in areas where the use of reason is called for. Kant gives three examples: we are in a state of “immaturity” when a book takes the place of our understanding, when a spiritual director takes the place of our conscience, when a doctor decides for us what our diet is to be. (Let us note in passing that the register of these three critiques is easy to recognize, even though the text does not make it explicit.) In any case, Enlightenment is defined by a modification of the preexisting relation linking will, authority, and the use of reason.
We must also note that this way out is presented by Kant in a rather ambiguous manner. He characterizes it as a phenomenon, an ongoing process; but he also presents it as a task and an obligation. From the very first paragraph, he notes that man himself is responsible for his immature status. Thus it has to be supposed that he will be able to escape from it only by a change that he himself will bring about in himself. Significantly, Kant says that this Enlightenment has a Wahlspruch: now a Wahlspruch is a heraldic device, that is, a distinctive feature by which one can be recognized, and it is also a motto, an instruction that one gives oneself and proposes to others. What, then, is this instruction? Aude sapere: “dare to know,” “have the courage, the audacity, to know.” Thus Enlightenment must be considered both as a process in which men participate collectively and as an act of courage to be accomplished personally. Men are at once elements and agents of a single process. They may be actors in the process to the extent that they participate in it; and the process occurs to the extent that men decide to be its voluntary actors.
A third difficulty appears here in Kant’s text in his use of the word “mankind”, Menschheit. The importance of this word in the Kantian conception of history is well known. Are we to understand that the entire human race is caught up in the process of Enlightenment? In that case, we must imagine Enlightenment as a historical change that affects the political and social existence of all people on the face of the earth. Or are we to understand that it involves a change affecting what constitutes the humanity of human beings? But the question then arises of knowing what this change is. Here again, Kant’s answer is not without a certain ambiguity. In any case, beneath its appearance of simplicity, it is rather complex.
Kant defines two essential conditions under which mankind can escape from its immaturity. And these two conditions are at once spiritual and institutional, ethical and political.

The first of these conditions is that the realm of obedience and the realm of the use of reason be clearly distinguished. Briefly characterizing the immature status, Kant invokes the familiar expression: “Don’t think, just follow orders”; such is, according to him, the form in which military discipline, political power, and religious authority are usually exercised. Humanity will reach maturity when it is no longer required to obey, but when men are told: “Obey, and you will be able to reason as much as you like.” We must note that the German word used here is räsonieren; this word, which is also used in the Critiques does not refer to just any use of reason, but to a use of reason in which reason has no other end but itself: räsonieren is to reason for reasoning’s sake. And Kant gives examples, these too being perfectly trivial in appearance: paying one’s taxes, while being able to argue as much as one likes about the system of taxation, would be characteristic of the mature state; or again, taking responsibility for parish service, if one is a pastor, while reasoning freely about religious dogmas.
We might think that there is nothing very different here from what has been meant, since the sixteenth century, by freedom of conscience: the right to think as one pleases so long as one obeys as one must. Yet it is here that Kant brings into play another distinction, and in a rather surprising way. The distinction he introduces is between the private and public uses of reason. But he adds at once that reason must be free in its public use, and must be submissive in its private use. Which is, term for term, the opposite of what is ordinarily called freedom of conscience.

But we must be somewhat more precise. What constitutes, for Kant, this private use of reason? In what area is it exercised? Man, Kant says, makes a private use of reason when he is “a cog in a machine”; that is, when he has a role to play in society and jobs to do: to be a soldier, to have taxes to pay, to be in charge of a parish, to be a civil servant, all this makes the human being a particular segment of society; he finds himself thereby placed in a circumscribed position, where he has to apply particular rules and pursue particular ends. Kant does not ask that people practice a blind and foolish obedience, but that they adapt the use they make of their reason to these determined circumstances; and reason must then be subjected to the particular ends in view. Thus there cannot be, here, any free use of reason.
On the other hand, when one is reasoning only in order to use one’s reason, when one is reasoning as a reasonable being (and not as a cog in a machine), when one is reasoning as a member of reasonable humanity, then the use of reason must be free and public. Enlightenment is thus not merely the process by which individuals would see their own personal freedom of thought guaranteed. There is Enlightenment when the universal, the free, and the public uses of reason are superimposed on one another.
Now this leads us to a fourth question that must be put to Kant’s text. We can readily see how the universal use of reason (apart from any private end) is the business of the subject himself as an individual; we can readily see, too, how the freedom of this use may be assured in a purely negative manner through the absence of any challenge to it; but how is a public use of that reason to be assured? Enlightenment, as we see, must not be conceived simply as a general process affecting all humanity; it must not be conceived only as an obligation prescribed to individuals: it now appears as a political problem. The question, in any event, is that of knowing how the use of reason can take the public form that it requires, how the audacity to know can be exercised in broad daylight, while individuals are obeying as scrupulously as possible. And Kant, in conclusion, proposes to Frederick II, in scarcely veiled terms, a sort of contract — what might be called the contract of rational despotism with free reason: the public and free use of autonomous reason will be the best guarantee of obedience, on condition, however, that the political principle that must be obeyed itself be in conformity with universal reason.
Let us leave Kant’s text here. I do not by any means propose to consider it as capable of constituting an adequate description of Enlightenment; and no historian, I think, could be satisfied with it for an analysis of the social, political, and cultural transformations that occurred at the end of the eighteenth century.
Nevertheless, notwithstanding its circumstantial nature, and without intending to give it an exaggerated place in Kant’s work, I believe that it is necessary to stress the connection that exists between this brief article and the three Critiques. Kant in fact describes Enlightenment as the moment when humanity is going to put its own reason to use, without subjecting itself to any authority; now it is precisely at this moment that the critique is necessary, since its role is that of defining the conditions under which the use of reason is legitimate in order to determine what can be known, what must be done, and what may be hoped. Illegitimate uses of reason are what give rise to dogmatism and heteronomy, along with illusion; on the other hand, it is when the legitimate use of reason has been clearly defined in its principles that its autonomy can be assured. The critique is, in a sense, the handbook of reason that has grown up in Enlightenment; and, conversely, the Enlightenment is the age of the critique.
It is also necessary, I think, to underline the relation between this text of Kant’s and the other texts he devoted to history. These latter, for the most part, seek to define the internal teleology of time and the point toward which history of humanity is moving. Now the analysis of Enlightenment, defining this history as humanity’s passage to its adult status, situates contemporary reality with respect to the overall movement and its basic directions. But at the same time, it shows how, at this very moment, each individual is responsible in a certain way for that overall process.
The hypothesis I should like to propose is that this little text is located in a sense at the crossroads of critical reflection and reflection on history. It is a reflection by Kant on the contemporary status of his own enterprise. No doubt it is not the first time that a philosopher has given his reasons for undertaking his work at a particular moment. But it seems to me that it is the first time that a philosopher has connected in this way, closely and from the inside, the significance of his work with respect to knowledge, a reflection on history and a particular analysis of the specific moment at which he is writing and because of which he is writing. It is in the reflection on “today” as difference in history and as motive for a particular philosophical task that the novelty of this text appears to me to lie.
And, by looking at it in this way, it seems to me we may recognize a point of departure: the outline of what one might call the attitude of modernity.
I know that modernity is often spoken of as an epoch, or at least as a set of features characteristic of an epoch; situated on a calendar, it would be preceded by a more or less naive or archaic premodernity, and followed by an enigmatic and troubling “postmodernity.” And then we find ourselves asking whether modernity constitutes the sequel to the Enlightenment and its development, or whether we are to see it as a rupture or a deviation with respect to the basic principles of the 18th century.
Thinking back on Kant’s text, I wonder whether we may not envisage modernity rather as an attitude than as a period of history. And by “attitude,” I mean a mode of relating to contemporary reality; a voluntary choice made by certain people; in the end, a way of thinking and feeling; a way, too, of acting and behaving that at one and the same time marks a relation of belonging and presents itself as a task. A bit, no doubt, like what the Greeks called an ethos. And consequently, rather than seeking to distinguish the “modern era” from the “premodern” or “postmodern,” I think it would be more useful to try to find out how the attitude of modernity, ever since its formation, has found itself struggling with attitudes of “countermodernity.”
To characterize briefly this attitude of modernity, I shall take an almost indispensable example, namely, Baudelaire; for his consciousness of modernity is widely recognized as one of the most acute in the nineteenth century.
1. Modernity is often characterized in terms of consciousness of the discontinuity of time: a break with tradition, a feeling of novelty, of vertigo in the face of the passing moment. And this is indeed what Baudelaire seems to be saying when he defines modernity as “the ephemeral, the fleeting, the contingent.”2 But, for him, being modern does not lie in recognizing and accepting this perpetual movement; on the contrary, it lies in adopting a certain attitude with respect to this movement; and this deliberate, difficult attitude consists in recapturing something eternal that is not beyond the present instant, nor behind it, but within it. Modernity is distinct from fashion, which does no more than call into question the course of time; modernity is the attitude that makes it possible to grasp the “heroic” aspect of the present moment. Modernity is not a phenomenon of sensitivity to the fleeting present; it is the will to “heroize” the present .
I shall restrict myself to what Baudelaire says about the painting of his contemporaries. Baudelaire makes fun of those painters who, finding nineteenth-century dress excessively ugly, want to depict nothing but ancient togas. But modernity in painting does not consist, for Baudelaire, in introducing black clothing onto the canvas. The modern painter is the one who can show the dark frock-coat as “the necessary costume of our time,” the one who knows how to make manifest, in the fashion of the day, the essential, permanent, obsessive relation that our age entertains with death. “The dress-coat and frock-coat not only possess their political beauty, which is an expression of universal equality, but also their poetic beauty, which is an expression of the public soul — an immense cortège of undertaker’s mutes (mutes in love, political mutes, bourgeois mutes…). We are each of us celebrating some funeral.”3 To designate this attitude of modernity, Baudelaire sometimes employs a litotes that is highly significant because it is presented in the form of a precept: “You have no right to despise the present.”
2. This heroization is ironical, needless to say. The attitude of modernity does not treat the passing moment as sacred in order to try to maintain or perpetuate it. It certainly does not involve harvesting it as a fleeting and interesting curiosity. That would be what Baudelaire would call the spectator’s posture. The flâneur, the idle, strolling spectator, is satisfied to keep his eyes open, to pay attention and to build up a storehouse of memories. In opposition to the flâneur, Baudelaire describes the man of modernity: “Away he goes, hurrying, searching …. Be very sure that this man … — this solitary, gifted with an active imagination, ceaselessly journeying across the great human desert — has an aim loftier than that of a mere flâneur, an aim more general, something other than the fugitive pleasure of circumstance. He is looking for that quality which you must allow me to call “modernity.” … He makes it his business to extract from fashion whatever element it may contain of poetry within history. As an example of modernity, Baudelaire cites the artist Constantin Guys. In appearance a spectator, a collector of curiosities, he remains “the last to linger wherever there can be a glow of light, an echo of poetry, a quiver of life or a chord of music; wherever a passion can pose before him, wherever natural man and conventional man display themselves in a strange beauty, wherever the sun lights up the swift joys of the depraved animal.”
3. But let us make no mistake. Constantin Guys is not a flâneur; what makes him the modern painter par excellence in Baudelaire’s eyes is that, just when the whole world is falling asleep, he begins to work, and he transfigures that world. His transfiguration does not entail an annulling of reality, but a difficult interplay between the truth of what is real and the exercise of freedom; “natural” things become “more than natural,” “beautiful” things become “more than beautiful,” and individual objects appear “endowed with an impulsive life like the soul of their creator.”5 For the attitude of modernity, the high value of the present is indissociable from a desperate eagerness to imagine it, to imagine it otherwise than it is, and to transform it not by destroying it but by grasping it in what it is. Baudelairean modernity is an exercise in which extreme attention to what is real is confronted with the practice of a liberty that simultaneously respects this reality and violates it.

4. However, modernity for Baudelaire is not simply a form of relationship to the present; it is also a mode of relationship that has to be established with oneself. The deliberate attitude of modernity is tied to an indispensable asceticism. To be modern is not to accept oneself as one is in the flux of the passing moments; it is to take oneself as object of a complex and difficult elaboration: what Baudelaire, in the vocabulary of his day, calls dandysme. Here I shall not recall in detail the well-known passages on “vulgar, earthy, vile nature”; on man’s indispensable revolt against himself; on the “doctrine of elegance” which imposes “upon its ambitious and humble disciples” a discipline more despotic than the most terrible religions; the pages, finally, on the asceticism of the dandy who makes of his body, his behavior, his feelings and passions, his very existence, a work of art. Modern man, for Baudelaire, is not the man who goes off to discover himself, his secrets and his hidden truth; he is the man who tries to invent himself. This modernity does not “liberate man in his own being”; it compels him to face the task of producing himself.
5. Let me add just one final word. This ironic heroization of the present, this transfiguring play of freedom with reality, this ascetic elaboration of the self — Baudelaire does not imagine that these have any place in society itself, or in the body politic. They can only be produced in another, a different place, which Baudelaire calls art.

I do not pretend to be summarizing in these few lines either the complex historical event that was the Enlightenment, at the end of the eighteenth century, or the attitude of modernity in the various guises it may have taken on during the last two centuries.
I have been seeking, on the one hand, to emphasize the extent to which a type of philosophical interrogation — one that simultaneously problematizes man’s relation to the present, man’s historical mode of being, and the constitution of the self as an autonomous subject — is rooted in the Enlightenment. On the other hand, I have been seeking to stress that the thread that may connect us with the Enlightenment is not faithfulness to doctrinal elements, but rather the permanent reactivation of an attitude — that is, of a philosophical ethos that could be described as a permanent critique of our historical era. I should like to characterize this ethos very briefly.
A. Negatively
This ethos implies, first, the refusal of what I like to call the “blackmail” of the Enlightenment. I think that the Enlightenment, as a set of political, economic, social, institutional, and cultural events on which we still depend in large part, constitutes a privileged domain for analysis. I also think that as an enterprise for linking the progress of truth and the history of liberty in a bond of direct relation, it formulated a philosophical question that remains for us to consider. I think, finally, as I have tried to show with reference to Kant’s text, that it defined a certain manner of philosophizing.

But that does not mean that one has to be “for” or “against” the Enlightenment. It even means precisely that one has to refuse everything that might present itself in the form of a simplistic and authoritarian alternative: you either accept the Enlightenment and remain within the tradition of its rationalism (this is considered a positive term by some and used by others, on the contrary, as a reproach); or else you criticize the Enlightenment and then try to escape from its principles of rationality (which may be seen once again as good or bad). And we do not break free of this blackmail by introducing “dialectical” nuances while seeking to determine what good and bad elements there may have been in the Enlightenment.

We must try to proceed with the analysis of ourselves as beings who are historically determined, to a certain extent, by the Enlightenment. Such an analysis implies a series of historical inquiries that are as precise as possible; and these inquiries will not be oriented retrospectively toward the “essential kernel of rationality” that can be found in the Enlightenment and that would have to be preserved in any event; they will be oriented toward the “contemporary limits of the necessary,” that is, toward what is not or is no longer indispensable for the constitution of ourselves as autonomous subjects.

This permanent critique of ourselves has to avoid the always too facile confusions between humanism and Enlightenment.
We must never forget that the Enlightenment is an event, or a set of events and complex historical processes, that is located at a certain point in the development of European societies. As such, it includes elements of social transformation, types of political institution, forms of knowledge, projects of rationalization of knowledge and practices, technological mutations that are very difficult to sum up in a word, even if many of these phenomena remain important today. The one I have pointed out and that seems to me to have been at the basis of an entire form of philosophical reflection concerns only the mode of reflective relation to the present.

Humanism is something entirely different. It is a theme or rather a set of themes that have reappeared on several occasions over time in European societies; these themes always tied to value judgments have obviously varied greatly in their content as well as in the values they have preserved. Furthermore they have served as a critical principle of differentiation. In the seventeenth century there was a humanism that presented itself as a critique of Christianity or of religion in general; there was a Christian humanism opposed to an ascetic and much more theocentric humanism. In the nineteenth century there was a suspicious humanism hostile and critical toward science and another that to the contrary placed its hope in that same science. Marxism has been a humanism; so have existentialism and personalism; there was a time when people supported the humanistic values represented by National Socialism and when the Stalinists themselves said they were humanists.

From this we must not conclude that everything that has ever been linked with humanism is to be rejected but that the humanistic thematic is in itself too supple too diverse too inconsistent to serve as an axis for reflection. And it is a fact that at least since the seventeenth century what is called humanism has always been obliged to lean on certain conceptions of man borrowed from religion science or politics. Humanism serves to color and to justify the conceptions of man to which it is after all obliged to take recourse.

Now in this connection I believe that this thematic which so often recurs and which always depends on humanism can be opposed by the principle of a critique and a permanent creation of ourselves in our autonomy: that is a principle that is at the heart of the historical consciousness that the Enlightenment has of itself. From this standpoint I am inclined to see Enlightenment and humanism in a state of tension rather than identity.

In any case it seems to me dangerous to confuse them; and further it seems historically inaccurate. If the question of man of the human species of the humanist was important throughout the eighteenth century this is very rarely I believe because the Enlightenment considered itself a humanism. It is worthwhile too to note that throughout the nineteenth century the historiography of sixteenth-century humanism which was so important for people like Saint-Beuve or Burckhardt was always distinct from and sometimes explicitly opposed to the Enlightenment and the eighteenth century. The nineteenth century had a tendency to oppose the two at least as much as to confuse them.

In any case I think that just as we must free ourselves from the intellectual blackmail of being for or against the Enlightenment we must escape from the historical and moral confusionism that mixes the theme of humanism with the question of the Enlightenment. An analysis of their complex relations in the course of the last two centuries would be a worthwhile project an important one if we are to bring some measure of clarity to the consciousness that we have of ourselves and of our past.
B. Positively
Yet while taking these precautions into account we must obviously give a more positive content to what may be a philosophical ethos consisting in a critique of what we are saying thinking and doing through a historical ontology of ourselves.
1. This philosophical ethos may be characterized as a limit-attitude. We are not talking about a gesture of rejection. We have to move beyond the outside-inside alternative; we have to be at the frontiers. Criticism indeed consists of analyzing and reflecting upon limits. But if the Kantian question was that of knowing what limits knowledge has to renounce transgressing, it seems to me that the critical question today has to be turned back into a positive one: in what is given lo us as universal necessary obligatory what place is occupied by whatever is singular contingent and the product of arbitrary constraints? The point in brief is to transform the critique conducted in the form of necessary limitation into a practical critique that lakes the form of a possible transgression.

This entails an obvious consequence: that criticism is no longer going to be practiced in the search for formal structures with universal value, but rather as a historical investigation into the events that have led us to constitute ourselves and to recognize ourselves as subjects of what we are doing, thinking, saying. In that sense, this criticism is not transcendental, and its goal is not that of making a metaphysics possible: it is genealogical in its design and archaeological in its method. Archaeological — and not transcendental — in the sense that it will not seek to identify the universal structures of all knowledge or of all possible moral action, but will seek to treat the instances of discourse that articulate what we think, say, and do as so many historical events. And this critique will be genealogical in the sense that it will not deduce from the form of what we are what it is impossible for us to do and to know; but it will separate out, from the contingency that has made us what we are, the possibility of no longer being, doing, or thinking what we are, do, or think. It is not seeking to make possible a metaphysics that has finally become a science; it is seeking to give new impetus, as far and wide as possible, to the undefined work of freedom.
2. But if we are not to settle for the affirmation or the empty dream of freedom, it seems to me that this historico-critical attitude must also be an experimental one. I mean that this work done at the limits of ourselves must, on the one hand, open up a realm of historical inquiry and, on the other, put itself to the test of reality, of contemporary reality, both to grasp the points where change is possible and desirable, and to determine the precise form this change should take. This means that the historical ontology of ourselves must turn away from all projects that claim to be global or radical. In fact we know from experience that the claim to escape from the system of contemporary reality so as to produce the overall programs of another society, of another way of thinking, another culture, another vision of the world, has led only to the return of the most dangerous traditions.

I prefer the very specific transformations that have proved to be possible in the last twenty years in a certain number of areas that concern our ways of being and thinking, relations to authority, relations between the sexes, the way in which we perceive insanity or illness; I prefer even these partial transformations that have been made in the correlation of historical analysis and the practical attitude, to the programs for a new man that the worst political systems have repeated throughout the twentieth century.

I shall thus characterize the philosophical ethos appropriate to the critical ontology of ourselves as a historico-practical test of the limits that we may go beyond, and thus as work carried out by ourselves upon ourselves as free beings.
3. Still, the following objection would no doubt be entirely legitimate: if we limit ourselves to this type of always partial and local inquiry or test, do we not run the risk of letting ourselves be determined by more general structures of which we may well not be conscious, and over which we may have no control?

To this, two responses. It is true that we have to give up hope of ever acceding to a point of view that could give us access to any complete and definitive knowledge of what may constitute our historical limits. And from this point of view the theoretical and practical experience that we have of our limits and of the possibility of moving beyond them is always limited and determined; thus we are always in the position of beginning again.

But that does not mean that no work can be done except in disorder and contingency. The work in question has its generality, its systematicity, its homogeneity, and its stakes.
Its Stakes
These are indicated by what might be called “the paradox of the relations of capacity and power.” We know that the great promise or the great hope of the eighteenth century, or a part of the eighteenth century, lay in the simultaneous and proportional growth of individuals with respect to one another. And, moreover, we can see that throughout the entire history of Western societies (it is perhaps here that the root of their singular historical destiny is located — such a peculiar destiny, so different from the others in its trajectory and so universalizing, so dominant with respect to the others), the acquisition of capabilities and the struggle for freedom have constituted permanent elements. Now the relations between the growth of capabilities and the growth of autonomy are not as simple as the eighteenth century may have believed. And we have been able to see what forms of power relation were conveyed by various technologies (whether we are speaking of productions with economic aims, or institutions whose goal is social regulation, or of techniques of communication): disciplines, both collective and individual, procedures of normalization exercised in the name of the power of the state, demands of society or of population zones, are examples. What is at stake, then, is this: How can the growth of capabilities be disconnected from the intensification of power relations?
Homogeneity
This leads to the study of what could be called “practical systems.” Here we are taking as a homogeneous domain of reference not the representations that men give of themselves, not the conditions that determine them without their knowledge, but rather what they do and the way they do it. That is, the forms of rationality that organize their ways of doing things (this might be called the technological aspect) and the freedom with which they act within these practical systems, reacting to what others do, modifying the rules of the game, up to a certain point (this might be called the strategic side of these practices). The homogeneity of these historico-critical analyses is thus ensured by this realm of practices, with their technological side and their strategic side.
Systematicity
These practical systems stem from three broad areas: relations of control over things, relations of action upon others, relations with oneself. This does not mean that each of these three areas is completely foreign to the others. It is well known that control over things is mediated by relations with others; and relations with others in turn always entail relations with oneself, and vice versa. But we have three axes whose specificity and whose interconnections have to be analyzed: the axis of knowledge, the axis of power, the axis of ethics. In other terms, the historical ontology of ourselves has to answer an open series of questions; it has to make an indefinite number of inquiries which may be multiplied and specified as much as we like, but which will all address the questions systematized as follows: How are we constituted as subjects of our own knowledge? How are we constituted as subjects who exercise or submit to power relations? How are we constituted as moral subjects of our own actions?
Generality
Finally, these historico-critical investigations are quite specific in the sense that they always bear upon a material, an epoch, a body of determined practices and discourses. And yet, at least at the level of the Western societies from which we derive, they have their generality, in the sense that they have continued to recur up to our time: for example, the problem of the relationship between sanity and insanity, or sickness and health, or crime and the law; the problem of the role of sexual relations; and so on.
But by evoking this generality, I do not mean to suggest that it has to be retraced in its metahistorical continuity over time, nor that its variations have to be pursued. What must be grasped is the extent to which what we know of it, the forms of power that are exercised in it, and the experience that we have in it of ourselves constitute nothing but determined historical figures, through a certain form of problematization that defines objects, rules of action, modes of relation to oneself. The study of modes of problematization (that is, of what is neither an anthropological constant nor a chronological variation) is thus the way to analyze questions of general import in their historically unique form.

A brief summary, to conclude and to come back to Kant.

I do not know whether we will ever reach mature adulthood. Many things in our experience convince us that the historical event of the Enlightenment did not make us mature adults, and we have not reached that stage yet. However, it seems to me that a meaning can be attributed to that critical interrogation on the present and on ourselves which Kant formulated by reflecting on the Enlightenment. It seems to me that Kant’s reflection is even a way of philosophizing that has not been without its importance or effectiveness during the last two centuries. The critical ontology of ourselves has to be considered not, certainly, as a theory, a doctrine, nor even as a permanent body of knowledge that is accumulating; it has to be conceived as an attitude, an ethos, a philosophical life in which the critique of what we are is at one and the same time the historical analysis of the limits that are imposed on us and an experiment with the possibility of going beyond them.

This philosophical attitude has to be translated into the labor of diverse inquiries. These inquiries have their methodological coherence in the at once archaeological and genealogical study of practices envisaged simultaneously as a technological type of rationality and as strategic games of liberties; they have their theoretical coherence in the definition of the historically unique forms in which the generalities of our relations to things, to others, to ourselves, have been problematized. They have their practical coherence in the care brought to the process of putting historico-critical reflection to the test of concrete practices. I do not know whether it must be said today that the critical task still entails faith in Enlightenment; I continue to think that this task requires work on our limits, that is, a patient labor giving form to our impatience for liberty.