Imagine you are asked to compose an ultra-short history of philosophy. Perhaps you’ve been challenged to squeeze the impossibly sprawling diversity of philosophy itself into just a few tweets. You could do worse than to search for the single word that best captures the ideas of every important philosopher. Plato had his ‘forms’. René Descartes had his ‘mind’ and John Locke his ‘ideas’. John Stuart Mill later had his ‘liberty’. In more recent philosophy, Jacques Derrida’s word was ‘text’, John Rawls’s was ‘justice’, and Judith Butler’s remains ‘gender’. Michel Foucault’s word, according to this innocent little parlour game, would certainly be ‘power’.

Foucault remains one of the most cited 20th-century thinkers and is, according to some lists, the single most cited figure across the humanities and social sciences. His two most referenced works, Discipline and Punish: The Birth of the Prison (1975) and The History of Sexuality, Volume One (1976), are the central sources for his analyses of power. Interestingly enough, however, Foucault was not always known for his signature word. He first gained his massive influence in 1966 with the publication of The Order of Things. The original French title gives a better sense of the intellectual milieu in which it was written: Les mots et les choses, or ‘Words and Things’. Philosophy in the 1960s was all about words, especially among Foucault’s contemporaries.

In other parts of Paris, Derrida was busily asserting that ‘there is nothing outside the text’, and Jacques Lacan turned psychoanalysis into linguistics by claiming that ‘the unconscious is structured like a language’. This was not just a French fashion. In 1967 Richard Rorty, surely the most infamous American philosopher of his generation, summed up the new spirit in the title of his anthology of essays, The Linguistic Turn. That same year, Jürgen Habermas, soon to become Germany’s leading philosopher, published his attempt at ‘grounding the social sciences in a theory of language’.

Foucault’s contemporaries pursued their obsessions with language for at least another few decades. Habermas’s magnum opus, titled The Theory of Communicative Action (1981), remained devoted to exploring the linguistic conditions of rationality. Anglo-American philosophy followed the same line, and so too did most French philosophers (except they tended toward the linguistic nature of irrationality instead).

For his part, however, Foucault moved on, somewhat singularly among his generation. Rather than staying in the world of words, in the 1970s he shifted his philosophical attention to power, an idea that promises to help explain how words, or anything else for that matter, come to give things the order that they have. But Foucault’s lasting importance is not in his having found some new master-concept that can explain all the others. Power, in Foucault, is not another philosophical godhead. For Foucault’s most crucial claim about power is that we must refuse to treat it as philosophers have always treated their central concepts, namely as a unitary and homogenous thing that is so at home with itself that it can explain everything else.

Foucault did not attempt to construct a philosophical fortress around his signature concept. He had witnessed first-hand how the arguments of the linguistic-turn philosophers grew brittle once they were deployed to analyse more and more by way of words. So Foucault himself expressly refused to develop an overarching theory of power. Interviewers would sometimes press him to give them a unified theory, but he always demurred. Such a theory, he said, was simply not the goal of his work. Foucault remains best-known for his analyses of power, indeed his name is, for most intellectuals, almost synonymous with the word ‘power’. Yet he did not himself offer a philosophy of power. How could this be possible?

Herein lies the richness and the challenge of Foucault’s work. His is a philosophical approach to power characterised by innovative, painstaking, sometimes frustrating, and often dazzling attempts to politicise power itself. Rather than using philosophy to freeze power into a timeless essence, and then to use that essence to comprehend so much of power’s manifestations in the world, Foucault sought to unburden philosophy of its icy gaze of capturing essences. He wanted to free philosophy to track the movements of power, the heat and the fury of it working to define the order of things.

To appreciate the originality of Foucault’s approach, it is helpful to contrast it to that of previous political philosophy. Before Foucault, political philosophers had presumed that power had an essence: be it sovereignty, or mastery, or unified control. The German social theorist Max Weber (1864-1920) influentially argued that state power consisted in a ‘monopoly of the legitimate use of physical force’. Thomas Hobbes (1588-1679), the English philosopher and original theorist of state power, saw the essence of power as state sovereignty. Hobbes thought that at its best and purest power would be exercised from the singular position of sovereignty. He called it ‘The Leviathan’.

Foucault never denied the reality of state power in the Hobbesian sense. But his political philosophy emanates from his skepticism about the assumption (and it was a mere assumption until Foucault called it into question) that the only real power is sovereign power. Foucault accepted that there were real forces of violence in the world, and not only state violence. There is also corporate violence due to enormous condensations of capital, gender violence in the form of patriarchy, and the violences both overt and subtle of white supremacy in such forms as chattel slavery, real-estate redlining, and now mass incarceration. Foucault’s work affirmed that such exercises of force were exhibits of sovereign power, likenesses of Leviathan. What he doubted was the assumption that we could extrapolate from this easy observation the more complex thought that power only ever appears in Leviathan-like form.

Power is all the more cunning because its basic forms can change in response to our efforts to free ourselves from its grip

In seeing through the imaginary singularity of power, Foucault was able to also envision it set against itself. He was able to hypothesise, and therefore to study, the possibility that power does not always assume just one form and that, in virtue of this, a given form of power can coexist alongside, or even come into conflict with, other forms of power. Such coexistences and conflicts, of course, are not mere speculative conundrums, but are the sort of stuff that one would need to empirically analyse in order to understand.

Foucault’s skeptical supposition thus allowed him to conduct careful enquiries into the actual functions of power. What these studies reveal is that power, which easily frightens us, turns out to be all the more cunning because its basic forms of operation can change in response to our ongoing efforts to free ourselves from its grip. To take just one example, Foucault wrote about the way in which a classically sovereign space such as the judicial court came to accept into its proceedings the testimony of medical and psychiatric experts whose authority and power were exercised without recourse to sovereign violence. An expert diagnosis of ‘insanity’ today or ‘perversity’ 100 years ago could come to mitigate or augment a judicial decision.

Foucault showed how the sovereign power of Leviathan (think crowns, congresses and capital) has over the past 200 years come to confront two new forms of power: disciplinary power (which he also called anatomo-politics because of its detailed attention to training the human body) and bio-politics. Biopower was Foucault’s subject in The History of Sexuality, Volume One. Meanwhile the power of discipline, the anatomo-politics of the body, was Foucault’s focus in Discipline and Punish.

More than any other book, it is Discipline and Punish in which Foucault constructs his signature, meticulous style of enquiry into the actual mechanisms of power. The recent publication of a now nearly complete set of Foucault’s course lectures at the Collège de France in Paris (probably the most prestigious academic institution in the world, and where Foucault lectured from 1970 to 1984) reveals that Discipline and Punish was the result of at least five years of intensive archival research. While Foucault worked on this book, he was deeply engaged in its material, leading research seminars and giving huge public lectures that are now being published under such titles as The Punitive Society and Psychiatric Power. The material he addressed ranges broadly, from the birth of modern criminology to psychiatry’s gendered construction of hysteria. The lectures show Foucault’s thought in development, and thus offer insight into his philosophy in the midst of its transformation. When he eventually organised his archival materials into a book, the result was the consolidated and efficient argumentation of Discipline and Punish.

Discipline, according to Foucault’s historical and philosophical analyses, is a form of power that tells people how to act by coaxing them to adjust themselves to what is ‘normal’. It is power in the form of correct training. Discipline does not strike down the subject at whom it is directed, in the way that sovereignty does. Discipline works more subtly, with an exquisite care even, in order to produce obedient people. Foucault famously called the obedient and normal products of discipline ‘docile subjects’.

The exemplary manifestation of disciplinary power is the prison. For Foucault, the important thing about this institution, the most ubiquitous site of punishment in the modern world (but practically non-existent as a form of punishment before the 18th century), is not the way in which it locks up the criminal by force. This is the sovereign element that persists in modern prisons, and is fundamentally no different from the most archaic forms of sovereign power that exert violent force over the criminal, the exile, the slave and the captive. Foucault looked beyond this most obvious element in order to see more deeply into the elaborate institution of the prison. Why had the relatively inexpensive techniques of torture and death gradually given way over the course of modernity to the costly complex of the prison? Was it just, as we are wont to believe, because we all started to become more humanitarian in the 18th century? Foucault thought that such an explanation would be sure to miss the fundamental way in which power changes when spectacles of torture give way to labyrinthine prisons.

The purpose of constant surveillance is to compel prisoners to regard themselves as subject to correction

Foucault argued that if you look at the way in which prisons operate, that is, at their mechanics, it becomes evident that they are designed not so much to lock away criminals as to submit them to training rendering them docile. Prisons are first and foremost not houses of confinement but departments of correction. The crucial part of this institution is not the cage of the prison cell, but the routine of the timetables that govern the daily lives of prisoners. What disciplines prisoners is the supervised morning inspections, the monitored mealtimes, the work shifts, even the ‘free time’ overseen by a panoply of attendants including armed guards and clipboard-wielding psychologists.

Importantly, all of the elements of prison surveillance are continuously made visible. That is why his book’s French title Surveiller et punir, more literally ‘Surveil and Punish’, is important. Prisoners must be made to know that they are subject to continual oversight. The purpose of constant surveillance is not to scare prisoners who are thinking of escaping, but rather to compel them to regard themselves as subject to correction. From the moment of morning rise to night’s lights out, the prisoners are subject to ceaseless behavioural inspection.

The crucial move of imprisonment is that of coaxing prisoners to learn how to inspect, manage and correct themselves. If effectively designed, supervision renders prisoners no longer in need of their supervisors. For they will have become their own attendant. This is docility.

To illustrate this distinctly modern form of power, Foucault used an image in Discipline and Punish that has become justly famous. From the archives of history, Foucault retrieved an almost-forgotten scheme of the canonical English moral philosopher Jeremy Bentham (1748-1832). Bentham proposed a maximal-surveillance prison he christened ‘The Panopticon’. Central to his proposal was that of an architecture designed for correction. In the Panopticon, the imposing materiality of the heavy stones and metal bars of physical imprisonment is less important than the weightless elements of light and air through which a prisoner’s every action would be traversed by supervision.

The design of the Panopticon was simple. A circle of cells radiate outward from a central guard tower. Each cell is positioned facing the tower and lit by a large window from the rear so that anyone inside the tower could see right through the cell in order to easily apprehend the activities of the prisoner therein. The guard tower is eminently visible to the prisoners but, because of carefully constructed blind windows, the prisoners cannot see back into the tower to know if they are being watched. This is a design of ceaseless surveillance. It is an architecture not so much of a house of detention as, in Bentham’s words, ‘a mill for grinding rogues honest’.

The Panopticon might seem to have remained a dream. No prison was ever built according to Bentham’s exact specifications, though a few came close. One approximation, the Stateville ‘F’ House in Illinois, was opened in 1922 and was finally closed down in late November 2016. But the important thing about the Panopticon was that it was a general dream. One need not be locked away in a prison cell to be subject to its designs of disciplinary dressage. The most chilling line in Discipline and Punish is the final sentence of the section entitled ‘Panopticism’, where Foucault wryly asks: ‘Is it surprising that prisons resemble factories, schools, barracks, hospitals, which all resemble prisons?’ If Foucault is right, we are subject to the power of correct training whenever we are tied to our school desks, our positions on the assembly line or, perhaps most of all in our time, our meticulously curated cubicles and open-plan offices so popular as working spaces today.

It was a bio-power wielded by psychiatrists and doctors that turned homosexuality into a ‘perversion’

To be sure, disciplinary training is not sovereign violence. But it is power. Classically, power took the form of force or coercion and was considered to be at its purest in acts of physical violence. Discipline acts otherwise. It gets a hold of us differently. It does not seize our bodies to destroy them, as Leviathan always threatened to do. Discipline rather trains them, drills them and (to use Foucault’s favoured word) ‘normalises’ them. All of this amounts to, Foucault saw, a distinctly subtle and relentless form of power. To refuse to recognise such disciplining as a form of power is a denial of how human life has come to be shaped and lived. If the only form of power we are willing to recognise is sovereign violence, we are in a poor position to understand the stakes of power today. If we are unable to see power in its other forms, we become impotent to resist all the other ways in which power brings itself to bear in forming us.

Foucault’s work shows that disciplinary power was just one of many forms that power has come to take over the past few hundred years. Disciplinary anatomo-politics persists alongside sovereign power as well as the power of bio-politics. In his next book, The History of Sexuality, Foucault argued that bio-politics helps us to understand how garish sexual exuberance persists in a culture that regularly tells itself that its true sexuality is being repressed. Bio-power does not forbid sexuality, but rather regulates it in the maximal interests of very particular conceptions of reproduction, family and health. It was a bio-power wielded by psychiatrists and doctors that, in the 19th century, turned homosexuality into a ‘perversion’ because of its failure to focus sexual activity around the healthy reproductive family. It would have been unlikely, if not impossible, to achieve this by sovereign acts of direct physical coercion. Much more effective were the armies of medical men who helped to straighten out their patients for their own supposed self-interest.

Other forms of power also persist in our midst. Some regard the power of data – that is the info-power of social media, data analytics and ceaseless algorithmic assessment – as the most significant kind of power that has emerged since Foucault’s death in 1984.

Those who fear freedom’s unpredictability find Foucault too risky

For identifying and so deftly analysing the mechanisms of modern power, while refusing to develop it into a singular and unified theory of power’s essence, Foucault remains philosophically important. The strident philosophical skepticism in which his thought is rooted is not directed against the use of philosophy for the analysis of power. Rather, it is suspicious of the bravado behind the idea that philosophy can, and also must, reveal the hidden essence of things. What this means is that Foucault’s signature word – ‘power’ – is not the name of an essence that he has distilled but is rather an index to an entire field of analysis in which the work of philosophy must continually toil.

Those who think that philosophy still needs to identify eternal essences will find Foucault’s perspective utterly unconvincing. But those who think that what feels eternal to each of us will vary across generations and geographies are more likely to find inspiration in Foucault’s approach. With respect to the central concepts of political philosophy, namely the conceptual pair of power and freedom, Foucault’s bet was that people are likely to win more for freedom by declining to define in advance all the forms that freedom could possibly take. That means too refusing to latch on to static definitions of power. Only in following power everywhere that it operates does freedom have a good chance of flourishing. Only by analysing power in its multiplicity, as Foucault did, do we have a chance to mount a multiplicity of freedoms that would counter all the different ways in which power comes to define the limits of who we can be.

The irony of a philosophy that would define power once and for all is that it would thereby delimit the essence of freedom. Such a philosophy would make freedom absolutely unfree. Those who fear freedom’s unpredictability find Foucault too risky. But those who are unwilling to decide today what might begin to count as freedom tomorrow find Foucault, at least with respect to our philosophical perspectives, freeing. Foucault’s approach to power and freedom therefore matters not only for philosophy, but also more importantly for what philosophy can contribute to the changing orders of things in which we find ourselves.