The German philosopher Peter Sloterdijk is the author of Spheres, a trilogy comprised of Bubbles, Globes, and Foams. Spheres is a thoroughly original redescription of human history. At 2,573 pages, it contains a complete account of Sloterdijk’s sphero-immunological thoughts.

Foams is written in three long chapters, each divided into long subchapters, each of which are comprised of many long subsections. The introduction describes the current situation of the human race. It, too, is very long. A somewhat shorter transitional section describes the social and political aspects of human existence. The book concludes with a staged conversation among an historian, a literary critic, and a theologian, who together reflect on the meaning and importance of Spheres.


Sloterdijk has attempted to rewrite the history of the human race using the notion of a sphere. It is a concept that encompasses topological, anthropological, psychological, political, social, immunological, and semiological aspects. Human beings always live within mostly self-created and self-maintained interiors. These are Sloterdijk’s spheres, and they range from the protective zone of the family and home, to the peer group, the apartment, the village, the city, the car, the school, or the nation.

Spheres thus come in all sizes. There are microspheres and macrospheres. Bubbles was devoted to microspheres, and, to a large extent, dealt with the prenatal state. This is the ur-Situation, as Sloterdijk calls it, from which every human being takes its departure, and that remains important throughout life. It functions as a model for all subsequent spheres in life, each of which is interpreted by Sloterdijk as an external recreation of the womb. Given their nourishing and protective nature, he designates these microspheres as immune systems; the same is true for macrospheres.

Because these spheres are shaped by the intimate relation between the child and the placenta in the womb, Sloterdijk stresses that their basic structure is dyadic. Collective immunity is more profound than individual immunity.1 This intimate relationship is the source of social solidarity. This sense of solidarity, currently so lacking in our individualized societies, can only be recovered by recapturing the primary experience of intimate closeness.2 Human coexistence always involves sharing “the same sphere of openness,” what Martin Heiddeger called Offenbarkeit; every human being “brings the sphere of [a] possible neighborhood with [him].”3 Coexistence precedes existence.

Populated spheres take shape wherever there is human life. A sphere can be defined as a shared, intimate, and disclosed inner space, one that human beings inhabit and on which their existence is vitally dependent. This may be the key to Sloterdijk’s conception of anthropology: human life is as much a matter of its various envelopes as anything else.4 Pace Heidegger, we are never thrown naked into the world.

In Globes, Sloterdijk considers the various macrospheres, from skyscrapers and apartment blocks to villages, cities, nation states, and religious systems, that human beings collectively inhabit during the course of their lives. The macrospheres serve materially, affectively, and symbolically to transfer the inner world onto the outside world, which in this way acquires a “soul.” This spheropoietic drive lies at the basis of human culture. Human history, writes Sloterdijk, is an account of humanity’s spheric enclosures, or the creation, destruction, and regeneration of its inner spaces. Starting from the domestic situation of the family, human beings have continually expanded their planetary reach; the expansion has now lost itself in “uninhabitable boundless space.”5 This moment becomes very important in the post-metaphysical, for Sloterdijk post-monospherical, world of ours that is the subject of Foams.

Both microspheres and macrospheres are spaces that grow through the selective incorporation and assimilation of what lies beyond their boundary, a process best described by the French verb engloutir. On Sloterdijk’s view, the history of metaphysics is a progressive building of worldviews as immune systems. Over time, smaller local cultures are integrated into the all-encompassing whole, what the Greeks called the cosmos. Western philosophy has always explained mankind with respect to its position and immersion in a greater whole. This whole, whether conceived as God, the cosmos, the world, or simply as Being, had a concentric-spherical structure, often laid out in some detail as an object of contemplation or admiration, and as a protective structure in which the individual soul could find guidance and, ultimately, safety. Existence, Sloterdijk writes, “is characterized by immersion in a final element;”6 what human beings are is to a large extent determined by where they are.

This is the motto of Sloterdijk’s anthropology: “Tell me what you are immersed in, and I will tell you what you are. [emphasis original]”7 As for the analogy between micro- and macrospheres, if fetus and placenta form the first pair, then God and the soul, or the cosmos and the individual intellect, form the last.8

Globes thus describes the history of religious and metaphysical thought as an attempt to “animate” the universe by describing it as an immune system, one modeled ultimately on existence in the womb. In the modern period, the universe was discovered to be infinite. The consequence was that describing the universe as an immune system unites in one design two things that exclude one another: a closed and finite immunological system, and an open and infinite universe. The universe had always been considered the ultimate source of immunity, and this is one part of the design. But immunity is a property of finite systems. The infinite universe, however, is remarkably indifferent to the individual.9 And this is the second part of the design. From a modernist perspective, the conclusion is inevitable. The attempt to animate the universe was doomed from the start.10 This conflict between immunity and infinity has left humanity in an absolute outside, the place beyond the last subway station. The world has become “a door to a thousand deserts silent and cold.”11 Metaphysical and religious systems have been steadily eroded over the last two centuries—like Jean-François Lyotard’s grand narratives. It is this somber thought that forms the backdrop to Foams.


The first form of life, Sloterdijk is persuaded, was a foam-born monad. Paleobiologists have called the most ancient bacterial fossils Swaziland microspheres. “Their existence,” Sloterdijk argues, “proves that the secret of life is inseparable from the secret of form, or more precisely from the formation of interiors according to spheric laws.”12 Human foam, on the other hand, is an agglomeration of bubbles:

[They are] systems or aggregates of spheric neighborhoods in which each individual “cell” constitutes a self-augmenting context (more colloquially: a world, a place), an intimate space of meaning whose tension is maintained by dyadic and pluripolar resonances, or a “household” that vibrates with its own individual animation, which can only be experienced by itself and within itself.13

A society is

an aggregate of microspheres (couples, households, businesses, associations) of different formats that, like the individual bubbles in a mountain of foam, border on one another and are layered over and under one another, yet without truly being accessible or effectively separable from one another.14

Foams are isolated and fragile. Individual bubbles are never in direct communication. They are only partially and selectively permeable:

[I]f Einstein lived next door, I would not know any more about the universe as a result. If the son of God and I had lived on the same floor for years, I would only learn afterwards—if at all—who my neighbor was.15

From this perspective, it is both impossible and undesirable to subordinate the plurality of bubbles to a single scheme or sphere. Our thinking should become fluid, light, soft.

Adieu, one hopes, to anthropo-, ethno-, ego- and logocentric deliria.16

Human beings are uniquely responsible for their own immunization. Spherology and immunology are ways of explaining metaphysics. They also reframe traditional philosophical questions from the perspective of life and the way it organizes and assures its own immunity. They overcome exhausted forms of thought, which, Sloterdijk claims, should be replaced by a general theory of immune and commune systems,17 a project that Foams explicitly aims to initiate.

The Implicit Explicit

Foams and spheres function in the background, where typically they are either forgotten or ignored. Was it Heidegger who talked of the forgetfulness of being? Here it is the forgetfulness of spheres. They become known only when their carrying capacity is exceeded (or exhausted), or when science and technology populate the world with artificial substitutes. For Sloterdijk, science and technology are a manner of explication, a view close to Heidegger’s idea that technology is a way of unveiling. For Heidegger, explication only uncovers what has always been known implicitly; there is no real outside out there. Sloterdijk, by contrast, argues that with technical or scientific explications, “when the implicit becomes explicit, something completely willful, foreign, different, something never intended, never expected, and never to be assimilated penetrates thought.”18 Radioactivity, carbon cycles, quasars, DNA, and neurons have no reflexive character whatsoever. They remain forever alien and external. The technological enlightenment reveals a world that is inhuman and monstrous.

Called the age of extremes by Eric Hobsbawm, the twentieth century excelled in destroying the planetary structures necessary for human existence. Ecological destruction has taught human beings what human habitation requires. Future civilizations will have to rely upon this hard-earned knowledge for their own survival. An example that Sloterdijk uses to good effect is the deployment of phosgene gas in the First World War, which served, among other things, as a “formal elaboration of the immersion of the living in a breathable milieu.”19 That men needed to breathe in order to live was, of course, known before the First World War. It was the experience of poison gas that made the implicit explicit. The destruction of Hiroshima and Nagasaki provide Sloterdijk with another example: radioactivity as an implicit part of nature becoming explicit in a blinding flash.20

In western Europe and the United States, homelessness is an economic state; but within the reach of the German language, Heimatlosigkeit designates the loss of traditional metaphysical comforts, a pastoral or poetic mode of inhabiting the earth, whether real or imagined. Sloterdijk reinterprets Heimatlosigkeit radically. Under his pen, it designates “the expatriation of humans from their natural air shell and their move to air-conditioned spaces.” It is a part of their “exodus from all possible niches of security in latency.”21 Heidegger imagined that it would be possible for men to return to “poetically dwelling on earth”—Heimatlosigkeit redeemed. Sloterdijk disagrees. The creation of a new way of living “[has] depend[ed] on great efforts of formal design, technical production, legal support, and political molding.”22 There is no going back. To survive we will have to make latent atmospheric conditions explicit,23 and this means coming to understand the most important of the climatic and ecological factors by which the atmosphere, the hydrosphere, the biosphere, the cryosphere (frozen water), and the pedosphere (land) are related.24

We are vitally dependent on the earth’s biosphere, yet “the containers and atmospheres that we must allow to surround us can no longer be taken for granted.”25 We have entered an age in which our “surroundings themselves became, or were recognized as [becoming], constructs.”26 It is this realization that ushers in the Anthropocene. Foams is an anthropocenic book avant la lettre. Sloterdijk has diagnosed the Anthropocene as marking the irrevocable end of what he calls the “backdrop ontology,” the state in which nature is nothing other than “the inoperative scenery behind human operations.”26 The backdrop is now becoming the foreground, and rapidly becoming a matter of life and death. Immune systems have become central concerns. Making the immune systems explicit means, Sloterdijk writes, in the most important and tragic messages of the book, that human intelligence must break its ancestral habit of trusting to the “backdrop ontology,” what the American philosopher Wilfrid Sellars wistfully called the myth of the given.28


In his first chapter, Sloterdijk develops a theory of capsules, islands, and hothouses as climatic enclaves that allow for human life. He distinguishes absolute islands, atmospheric islands, and anthropogenic islands. The first comprise ships, airplanes, and space stations. The space station is the most characteristic of the absolute islands; within it, survival is absolutely contingent on technology.29 Space travel is, in fact, eminently useful for rethinking the human condition in the Anthropocene. It allows us to think of nature as a

found, spontaneously populated life support system whose workings its residents cannot imagine in any physically adequate way as long as they inhabit it “existentially,” that is to say operate in the modus of intuition, devotion and ritual-metaphorical interpretation.30

Space travel is a key discipline of “experimental anthropology” because it expresses life on earth as embedded in a life support system, the implicit once again becoming explicit.

Atmospheric islands are artificial imitations of the natural greenhouses that enable human life. Both London’s Crystal Palace, which opened in 1851, and Biosphere 2 in Arizona, which was operational from 1991 to 1994, are discussed in some detail.

The anthropogenic islands are cultural spaces.31 In these evolutionary islands, isolation from the natural environment unleashes, or, at least, makes possible, “the self-incubation of homo sapiens.” Such anthropogenic islands are the real production sites of what Heidegger came to call a clearing.32

The anthroposphere is a “human hothouse.” It is here that the process of hominization of our primate ancestors took place. In this description, Sloterdijk relies on insights derived from the German tradition of philosophical anthropology, mostly Arnold Gehlen and Dieter Claessens.

Architecture and Luxury

The second chapter of Foams deals with architecture. The apartment and the skyscraper are spatial immune systems. Special attention is given to the modern apartment, a spatial arrangement in which isolated individuals are allowed a form of coexistence. A section entitled “foam city” discusses the macrointeriors and assembly buildings of modern urban areas, such as stadiums, congress halls, and other large architectural constructs in which masses of people can gather for collective events.

Today’s cities are typically foams.33

In his third and last chapter, Sloterdijk sketches the outlines of a new philosophical anthropology, one inspired by Gehlen and other representatives of the German tradition of philosophical anthropology. He gives it a new twist. Gehlen regarded human beings as rich in their shortcomings, the German word Mängelwesen conveying far more than shortcomings ever could. Not for Sloterdijk is this idea of humanity. Instead, humans are beings of luxury, profiting since the dawn of human evolution from “a singular incubator privilege.”34 Other animals must scrounge for their existence; human beings are creatures of pampering, or Verwöhnung, a word that in German conveys a sense of entitlement entirely absent from the English. Pampering, Sloterdijk argues, is the real driving force behind human evolution.

Homo sapiens “is a basally pampered, polymorphically luxuriating, multiply improvable intermediate being.”35

During infancy, Sloterdijk explains, newborn children profit extensively from “a positive feedback of pampering effects” offered first within the mother–child space, a microhothouse, and later, by the larger anthroposphere. Benefiting from its continued protection, the child is allowed to remain an infant. The defense of childhood is the essence of culture. Anthropospheres, or cultural spaces, are generators of wealth and increasing surplus. As such, the improbable has become a daily routine.36

Sloterdijk concludes his third chapter with a discussion of the welfare state. Alluding to a book by Richard Dawkins, he writes that “Climbing Mount Improbable would be a good name for what we have been doing since the Industrial Revolution.”37 It is in our current affluent consumer societies that the true nature of humanity manifests itself. Gehlen and Heidegger, Sloterdijk remarks, indulged themselves in a suspicious love of hardship, what Sloterdijk dismisses as “old European-heroic sentiments” of “letting-oneself-be-summoned to the hard, heavy and necessary.” Sloterdijk, however, celebrates philosophical levity. Frivolity, uplift, surplus, and drift are the most typical, and certainly the most glorious, features of human existence. Sloterdijk explores and celebrates the many ways in which human beings have triumphantly managed to defy the gravities of existence, the weight of the world. “[A]nti-gravity,” he writes, “is more serious than anything ever formulated about the supposedly ‘fundamental’ by the consensus.”38 Foams is a critique of heavy reason.39

By contrast, Giorgio Agamben has recently claimed that the modern human subject is, in essence, a form of “bare life,” and has compared today’s social system with a concentration camp.40 “It is in no sense ‘bare life,’” Sloterdijk objects, “that determines the subject’s form in the luxury hothouse, but rather the possession of spending power in combination with mobilized appetites.”41 As Sloterdijk admits, however, three-quarters of the world’s population is, of course, excluded from this particular hothouse.42

The improbably luxurious conditions of affluent societies may one day cease to exist, a possibility vaguely sensed by their members. Luxury yet reigns supreme, as the last section of Sloterdijk’s book documents. Postmodern, affluent society enforces the “general subjugation of life to the choice between boredom and entertainment,”43 and although Sloterdijk does not explicitly say so, he might agree with Gilles Châtelet’s comment that it summons us “to live and think like pigs.”44


Like the massive Spheres trilogy as a whole, originally intended by Sloterdijk to take the form of a literary bildungsroman, Foams is written in a rich and playful style. His tone is jovial and detached, ironic yet joyful, reminiscent of a certain side of Friedrich Nietzsche. It also owes much to Diogenes. It is a far cry from anything considered as serious thought in the predominantly analytic world of Anglophone philosophy. Even among so-called continental philosophers, and in particular among his German academic colleagues, Sloterdijk remains a controversial, if not a vilified, figure, a status he has cultivated by calling himself a philosophical writer, a Schriftsteller. It is precisely in this lightness and deliberate antiseriousness that Sloterdijk is most subversive. In the conclusion to his trilogy, he writes that

[T]he terminological surface of spherology is already a deterrent against anything geared toward seriousness, power, and ratings. Power seekers from all sectors will carefully avoid speaking of foams, let alone bubbles. … The texts have a built-in imitation block that functions reliably under the given sociopsychological conditions. Mere quotation is already a risk for those who quote, and that should remain the case.45

By making such grand pronouncements, Sloterdijk has effectively distanced himself from academic publishing. No academics need intrude. The images and photographs that appear in this book and many of Sloterdijk’s other books are a peculiar feature of his artistic style. He uses images as philosophy, and was very possibly inspired by Oskar Negt and Alexander Kluge’s Geschichte und Eigensinn (History and Obstinacy), as well as Susan Buck-Morss’s Dreamworld and Catastrophe.46

If there is one philosophical work that most resembles Spheres, it is Oswald Spengler’s Der Untergang des Abendlandes (The Decline of the West). They are both works on the grand scale. But Spheres is, in its spirit and tone, far removed from Spengler’s book, which does not, under the best of circumstances, make for light reading. It is also philosophically far more profound, productive, and progressive. Sloterdijk’s style is parodic, ironic, and intensely humorous. Voices from the philosophical tradition resonate on every page. Much of the fun simply seems to evaporate in the English translation. Sloterdijk’s brilliant expressiveness relies very much on the subtleties of the German language; these do not always survive translation. Taking this into account, the translator has done a fairly good job. Not always. At one point, Postpessimismus appears as pessimism.47 Not quite.

  1. Peter Sloterdijk, Foams: Spheres III (Los Angeles: Semiotext(e), 2016), 13. 
  2. Peter Sloterdijk, Foams: Spheres III (Los Angeles: Semiotext(e), 2016), 14. This closeness is also the source, as Sloterdijk aims to show, of all religious affects and is the real ground of all theological speculation. 
  3. Peter Sloterdijk, Foams: Spheres III (Los Angeles: Semiotext(e), 2016), 15. 
  4. Bruno Latour, “A Cautious Prometheus? A Few Steps Toward a Philosophy of Design (with Special Attention to Peter Sloterdijk),” Keynote lecture for the Networks of Design meeting of the Design History Society, Falmouth, Cornwall, September 3, 2008. 
  5. Peter Sloterdijk, Foams: Spheres III (Los Angeles: Semiotext(e), 2016), 16. 
  6. Peter Sloterdijk, Foams: Spheres III (Los Angeles: Semiotext(e), 2016), 17. 
  7. Peter Sloterdijk, Foams: Spheres III (Los Angeles: Semiotext(e), 2016), 17. 
  8. Peter Sloterdijk, Foams: Spheres III (Los Angeles: Semiotext(e), 2016), 18. 
  9. Peter Sloterdijk, Foams: Spheres III (Los Angeles: Semiotext(e), 2016), 19. 
  10. The Spheres project, although enabled only from the modern perspective of the collapse of the monosphere, is written “from the inside.” In a quasi-Hegelian mode, it attempts to describe spheropoiesis from its inner unfolding. We may now retrospectively say that metaphysical immune projects were doomed to fail from the start, but this was not at all obvious for those involved, living as they were in a “closed world,” to use Alexandre Koyré’s expression. 
  11. Friedrich Nietzsche, Fröhliche Wissenschaft, cited in Karl Barth, Church Dogmatics: Volume 3 - The Doctrine of Creation, trans. Harold Knight et al., (A&C Black, 2004), 235. 
  12. Peter Sloterdijk, Foams: Spheres III (Los Angeles: Semiotext(e), 2016), 50. 
  13. Peter Sloterdijk, Foams: Spheres III (Los Angeles: Semiotext(e), 2016), 52. 
  14. Peter Sloterdijk, Foams: Spheres III (Los Angeles: Semiotext(e), 2016), 56. 
  15. Peter Sloterdijk, Foams: Spheres III (Los Angeles: Semiotext(e), 2016), 58. 
  16. Peter Sloterdijk, Foams: Spheres III (Los Angeles: Semiotext(e), 2016), 60. 
  17. Peter Sloterdijk, Foams: Spheres III (Los Angeles: Semiotext(e), 2016), 25. 
  18. Peter Sloterdijk, Foams: Spheres III (Los Angeles: Semiotext(e), 2016), 74. 
  19. Peter Sloterdijk, Foams: Spheres III (Los Angeles: Semiotext(e), 2016), 97. 
  20. Peter Sloterdijk, Foams: Spheres III (Los Angeles: Semiotext(e), 2016), 130. 
  21. Peter Sloterdijk, Foams: Spheres III (Los Angeles: Semiotext(e), 2016), 135. 
  22. Peter Sloterdijk, Foams: Spheres III (Los Angeles: Semiotext(e), 2016), 137. 
  23. Peter Sloterdijk, Foams: Spheres III (Los Angeles: Semiotext(e), 2016), 158. 
  24. Peter Sloterdijk, Foams: Spheres III (Los Angeles: Semiotext(e), 2016), 160. 
  25. Peter Sloterdijk, Foams: Spheres III (Los Angeles: Semiotext(e), 2016), 180. 
  26. Peter Sloterdijk, Foams: Spheres III (Los Angeles: Semiotext(e), 2016), 181. 
  27. Peter Sloterdijk, “The Anthropocene: A Process-State at the Edge of Geohistory?”, trans. Anna-Sophie Springer, in Art in the Anthropocene: Encounters Among Aesthetics, Politics, Environments and Epistemologies, ed. Heather Davis and Etienne Turpin (London: Open Humanities, 2015), 334. 
  28. Peter Sloterdijk, Foams: Spheres III (Los Angeles: Semiotext(e), 2016), 183. 
  29. Peter Sloterdijk, Foams: Spheres III (Los Angeles: Semiotext(e), 2016), 299. 
  30. Peter Sloterdijk, Foams: Spheres III (Los Angeles: Semiotext(e), 2016), 301. 
  31. These anthropogenic islands, or anthropospheres, are made up of nine topological dimensions or topoi, each responsible for a different yet synergistic aspect of their anthropogenic operativity: the chirotope or the operational realm of human hands; the phono- or logotope or the vocal, and later also literary, dome shared by the sphere’s inhabitants; the utero- or hysterotope or the expanded zone of maternal care; the thermotope or the space of shared comforts; the erototope or the space of erotic transferences; the ergo- or phallotope or the space of shared work and a shared sense (sensus communis); the aletho- or mnemotope or the truth-gathering site; the thanato- or theotope or the space of the dead, ghosts, and the gods; and finally the nomotope or the space of shared mores and customs. 
  32. Peter Sloterdijk, Foams: Spheres III (Los Angeles: Semiotext(e), 2016), 458. 
  33. Peter Sloterdijk, Foams: Spheres III (Los Angeles: Semiotext(e), 2016), 654. 
  34. Peter Sloterdijk, Foams: Spheres III (Los Angeles: Semiotext(e), 2016), 657. 
  35. Peter Sloterdijk, Foams: Spheres III (Los Angeles: Semiotext(e), 2016), 657. 
  36. Peter Sloterdijk, Foams: Spheres III (Los Angeles: Semiotext(e), 2016), 711. 
  37. Peter Sloterdijk, Foams: Spheres III (Los Angeles: Semiotext(e), 2016), 822. It is the world that Michael Hardt and Antonio Negri identified as being simultaneously Empire and the multitude (see Michael Hardt and Antonio Negri, Empire (Massachusetts: Harvard University Press, 2000), for Sloterdijk a sign that the radical subversive pretense of their book is futile and anachronistic. 
  38. Peter Sloterdijk, Foams: Spheres III (Los Angeles: Semiotext(e), 2016), 687. 
  39. Peter Sloterdijk, Foams: Spheres III (Los Angeles: Semiotext(e), 2016), 682. 
  40. Giorgio Agamben, Homo Sacer: Sovereign Power and Bare Life (Stanford: Stanford University Press, 1998); Homo sacer: Il potere sovrano e la nuda vita (Giulio Einuadi, 1995). 
  41. Peter Sloterdijk, Foams: Spheres III (Los Angeles: Semiotext(e), 2016), 775. 
  42. Peter Sloterdijk, Foams: Spheres III (Los Angeles: Semiotext(e), 2016), 824. 
  43. Peter Sloterdijk, Foams: Spheres III (Los Angeles: Semiotext(e), 2016), 779. 
  44. Gilles Châtelet, To Live and Think Like Pigs: The Incitement of Envy and Boredom in Market Democracies (London: Urbanomic, 2014). 
  45. Peter Sloterdijk, Foams: Spheres III (Los Angeles: Semiotext(e), 2016), 807–8. 
  46. Oskar Negt and Alexander Kluge, History and Obstinacy, ed. Devin Fore (New York: Zone Books, 2014), German original pub. in 1981; Susan Buck-Morss, Dreamworld and Catastrophe: The Passing of Mass Utopia in East and West (Cambridge, MA: The MIT Press, 2000). 
  47. Peter Sloterdijk, Foams: Spheres III (Los Angeles: Semiotext(e), 2016), 820.