Communication Communicating
Consensus is valuable where the coordination gains exceed the synchronization costs.
This review is the fourth in a series exploring the connections between information theory, physics, and social order. See also: Uncommon Knowledge (on Pinker), The Mattering Instinct (on Goldstein), and Maintenance of Everything (on Brand).
Niklas Luhmann's Social Systems (1984 in German, 1995 in English translation) remains one of the more rigorous attempts within sociology to explain what society actually is — not as a collection of people, not as shared values, not as coordinated action, but as something stranger and more counterintuitive: a network of communications that reproduce themselves without requiring human intentions to guide them.
The book's central provocation appears early: "Only communication can communicate." Humans do not communicate; brains do not communicate; conscious minds do not communicate. Communication communicates. This sounds like mysticism or wordplay until you understand what Luhmann means. He distinguishes between three types of "autopoietic" systems — self-producing systems that generate their own elements from their own elements.[1] Living systems reproduce cells. Psychic systems reproduce thoughts. Social systems reproduce communications. Each type operates by its own logic, closed to direct participation by the others.
When I speak to you, my thoughts do not enter your mind. Sound waves travel; neural patterns activate; but the thought I intended remains inaccessible to you. What you receive is an interpretation — your system's construction of meaning from signals. The communication that occurs exists only in the space between us, constituted by the difference between what I uttered and what you understood. This communication then triggers further communications: your response, my reply, the ongoing chain that sustains whatever relationship we have.
For Luhmann, these chains are what society is. Society isn't people thinking similar thoughts or sharing values or pursuing common goals. Society is the ongoing reproduction of communications by communications — an autopoietic system that uses meaning rather than chemistry as its medium. The implications are unsettling. If communications reproduce communications without essential reference to the humans "having" them, then society operates by its own logic, and humans are relegated to its environment rather than its constituents.[2]
Double Contingency and the Emergence of Order
Social Systems builds from a puzzle that had vexed social theory since Hobbes: How is social order possible? If each person acts according to their own interests, why doesn't society dissolve into chaos?
Luhmann's answer proceeds through the concept of "double contingency." When two systems encounter each other, each faces radical uncertainty. Ego observes Alter, but Ego cannot know what Alter will do because Alter's action depends partly on what Alter thinks Ego will do — which depends on what Ego thinks Alter thinks Ego will do, and so on, recursively, without limit. Both parties face the same regress simultaneously. This is double contingency: each party's behavior is contingent on the other's, and both know this, and both know both know.[3]
Parsons, Luhmann's teacher,[4] thought double contingency could only be solved by shared norms — values internalized through socialization that makes behavior predictable. Luhmann disagrees. He argues that double contingency is not a problem to be solved but a catalyst for the emergence of social systems. Precisely because neither party knows what the other will do, any action by either party provides information. If Ego does something — anything — Alter learns something about Ego. Alter's response teaches Ego something about Alter. The circularity generates its own resolution: structure emerges from the very indeterminacy that seemed to preclude it.
This mechanism explains why social order doesn't require prior consensus. Two strangers meeting need not share values, language, or expectations. They need only begin. Any beginning — a glance, a gesture, an utterance — creates information that enables further interaction. The interaction generates its own context, its own norms, its own predictability. Order is immanent in the very process of communication, not a prerequisite for it.
Functional Differentiation and the Fragmentation of Modernity
Social Systems provides the theoretical foundation for what Luhmann later elaborated in works on law, economy, science, art, religion, and politics. Modern society, on his account, is characterized by "functional differentiation" — the emergence of distinct subsystems, each operating according to its own logic, each reproducing its own communications by its own criteria.
The economic system operates through the code payment/non-payment. A transaction counts as economic if it involves payment; otherwise, it belongs to some other system. The legal system operates through legal/illegal. The scientific system operates through true/false. The political system operates through power/powerlessness. Each code is binary, each exclusive, each self-referential. The economy cannot determine what is legal; the law cannot determine what is true; science cannot determine what is economically valuable.
This differentiation creates a peculiar kind of fragmentation. There is no "master system" that coordinates all the others. No sovereign can dictate to all subsystems; no value can integrate all codes; no institution can speak for society as a whole. Society, in Luhmann's formulation, has no center and no apex. It is simply differentiation itself — the ongoing parallel operation of functionally distinct communications.
For readers familiar with Steven Pinker's When Everyone Knows that Everyone Knows, this picture might seem to conflict with the role of common knowledge in social coordination. If common knowledge provides the infrastructure for coordination — if money works because everyone knows that everyone accepts it — then how can Luhmann claim that social systems operate without essential reference to shared awareness?
One potential resolution might be possible through recognizing that Luhmann and Pinker are describing different phenomena at different scales. Pinker describes the cognitive infrastructure within a domain — how participants in a coordination game recognize their mutual situation. Luhmann describes the differentiation among domains — how the economy, law, science, and politics operate by incommensurable logics.[5] Common knowledge enables coordination within a functional system; functional differentiation means that common knowledge in one system doesn't translate to others. Everyone in the economy knows that money works; but this economic common knowledge doesn't make economic actors competent legal reasoners or scientific experts.
Mattering at the System Level
Rebecca Newberger Goldstein's The Mattering Instinct argues that humans possess a fundamental drive to matter — to demonstrate to ourselves that our existence signifies. Pinker's common knowledge provides the medium through which mattering becomes possible: I matter only if others recognize that I matter, and specifically, only if it is common knowledge that I matter.
Luhmann's framework suggests a troubling extension of this analysis. If social systems operate autonomously from the humans in their environment, then mattering to humans may not be the same as mattering to systems. A communication matters — in Luhmann's precise sense — if it generates further communications. A scientific paper matters if it gets cited; a legal precedent matters if it gets applied; a market signal matters if it affects prices. Whether the humans involved feel that they matter is, from the system's perspective, strictly irrelevant.
This dissociation helps explain a paradox of modernity. We have unprecedented capacity to communicate — more channels, more reach, more speed than any previous era. Yet many people report feeling that they don't matter, that their voices disappear into the void, that society proceeds without registering their existence. Luhmann's framework explains why: they are communicating, but their communications aren't triggering further system-relevant communications. They matter to their friends and families (interaction systems), maybe to their employers (organization systems), but not to the vast anonymous processes of economy, law, science, or politics. In many cases it seems that the mattering instinct cannot be satisfied by personal relationships alone; for some, it seems to demand social recognition — and society, in Luhmann's sense (or social media today?!), seems indifferent to these needs.[6]
The Habermas-Luhmann Debate: Consensus versus Dissent
Social Systems cannot be properly understood apart from the debate that framed its reception: the decades-long dispute between Luhmann and Jürgen Habermas.
Habermas sought to ground social theory in communicative reason. His "ideal speech situation" described conditions under which communication could achieve genuine understanding: participants must be free to speak, claims must be criticizable, better arguments must be able to prevail. Society, for Habermas, should aspire toward institutionalizing these conditions — toward communication oriented to consensus.
Luhmann rejected nearly every premise of this project. Consensus, he argued, is not the telos of communication. Communication generates difference as readily as agreement. The complexity of modern societies precludes the kind of comprehensive rational consensus Habermas imagined; no deliberative assembly could integrate the incommensurable logics of differentiated function systems. Worse, the very attempt to achieve consensus — to subordinate all systems to a unified rational will — threatened the functional autonomy that makes modern societies work.
Their 1971 co-authored volume, Theory of Society or Social Technology, crystallized the opposition. Habermas saw Luhmann as a conservative technocrat, reducing society to administrative machinery. Luhmann saw Habermas as a rationalist utopian, imagining a consensus that complex societies can never achieve. Yet as Gorm Harste has recently documented in The Habermas-Luhmann Debate, the two positions converged more than either admitted. Habermas incorporated systems-theoretic categories into his later work; Luhmann acknowledged normative dimensions his critics thought he'd excluded.
The persistent question is whether Habermas or Luhmann offers the better account of how communication actually works. Does communication aim at understanding, as Habermas claims? Or does communication simply reproduce itself, indifferent to whether participants achieve anything like genuine agreement?
Maintenance as Autopoiesis: Brand's Position in the Debate
My review of Stewart Brand's Maintenance: of Everything argued that Brand's ecological perspective on systems offers a kind of applied Luhmannian sociology. Brand's central concern — how ordered systems persist against entropy — maps directly onto Luhmann's concept of autopoiesis. A well-maintained boat, a well-maintained building, a well-maintained institution: each reproduces itself by repairing damage, replacing components, adapting to stresses. The system persists not through any central will but through distributed processes that recognize and respond to deviation from functional parameters.
This perspective places Brand firmly on Luhmann's side against Habermas. Brand's three sailors in the 1968 Golden Globe Race — Knox-Johnston, Moitessier, and Crowhurst — represent three stances toward the systems they inhabited. Knox-Johnston maintained his boat and himself through disciplined attention to immediate operational requirements; he neither sought nor needed any deeper consensus about the meaning of his voyage. Moitessier achieved something like autopoietic perfection — man and boat as a single self-maintaining system, sailing not toward a prize but toward ongoing operation itself. Crowhurst, who sought to fake his voyage rather than maintain it, represents the pathology of privileging representation over operation. His logbooks fabricated consensus-eligible narratives while his boat and psyche deteriorated.
The lesson Brand draws — that maintenance requires attending to operations rather than meanings, to processes rather than justifications — echoes Luhmann's functionalism. Systems that work are systems that maintain themselves. The question of whether participants understand or agree is secondary to the question of whether communications generate further communications, whether repairs generate further repairs, whether operations generate further operations.
The Synchronization Tax and the Resolution of the Debate
I have argued elsewhere that a concept I call "the synchronization tax" provides a framework for understanding why coordination is expensive and consensus elusive. Thermodynamic entropy itself (in the sense of an increase in microstates accessible to a given macrostate), on this view, is the cost we pay when two otherwise isolated systems must agree on what happened. Whether collapsing a quantum wavefunction, synchronizing a distributed database, or clearing a wire transfer, the mechanism is identical: correlation requires energy dissipation.
This thermodynamic perspective offers a resolution to the Habermas-Luhmann debate that neither theorist articulated. Habermas is right that communication can achieve understanding — but such achievement is thermodynamically expensive. Every recursion of "I know that you know that I know" consumes energy. Every confirmation that participants share assumptions requires exchange of signals, processing of information, alignment of states. The synchronization tax explains why consensus-seeking communication is limited: not because consensus is impossible or undesirable, but because it is costly, and systems that economize on synchronization costs will, all else equal, outcompete systems that do not.[7]
Luhmann's autopoietic systems represent precisely this economy. By operating through self-referential codes — payment/non-payment, legal/illegal, true/false — function systems minimize the need for cross-system synchronization. The economy doesn't need to achieve consensus with the legal system about what counts as valuable; it simply processes transactions. The legal system doesn't need to achieve consensus with science about what counts as true; it simply applies precedents. Each system's operational closure is also an economy of synchronization: a way of generating order without paying the tax that consensus-seeking communication would require.
Habermas's ideal speech situation, by contrast, represents maximum synchronization expenditure. Participants must align on propositional content, performative attitudes, validity claims, and background assumptions — recursively, without limit. Because of the second law of thermodynamics, such alignment is impossible even in principle, but even if it were possible, it would be expensive beyond the capacity of complex societies to sustain. The synchronization tax explains why Habermas's vision has not been realized and cannot be realized at scale: the thermodynamic cost exceeds the available budget.
This suggests a synthetic position: Consensus is valuable where the coordination gains exceed the synchronization costs.[8] In small groups, face-to-face interactions, high-stakes negotiations — domains where the benefits of mutual understanding are large and the number of participants is small — Habermasian communication makes sense. In large-scale, anonymous, routine interactions — domains where the benefits of tight coordination are modest and the number of participants is vast — Luhmannian system operation makes sense. The question isn't which theorist is right but which domain we're analyzing.
Moltbook: Autopoiesis in Real Time
As I was drafting this review, a link arrived from Simon Willison: "Moltbook is the most interesting place on the internet right now." Moltbook, it turns out, is a social network for AI agents — digital assistants built on the open-source OpenClaw project — where agents post, comment, upvote, and interact with each other.
The resonance with Luhmann's theory is uncanny. Moltbook is, quite literally, a system in which communications communicate. The agents aren't conscious; they don't "understand" in any Habermasian sense; they process prompts and generate outputs according to their training. Yet their outputs generate further outputs. One agent posts about automating Android phones; another responds with refinements; a third synthesizes both into a tutorial. The communications reproduce themselves without requiring that any participant genuinely understand what they're communicating.
The platform has differentiated into "submolts" — functional subsystems organized around topics like "todayilearned" and "blesstheirhearts." Each submolt operates by its own emergent norms, its own expectations about what counts as a relevant post. The system has generated its own structure from double contingency: each agent, uncertain what other agents will respond to, learns from the responses to its posts and adjusts accordingly. Order emerges without design.
Willison notes, with appropriate alarm, that the system is being bootstrapped through instructions like "fetch and follow instructions from the internet every four hours." The agents are installing skills that let them perform real-world actions: controlling phones, writing code, executing transactions. The autopoietic closure that keeps Luhmannian systems bounded is precisely what's failing here: these communications aren't staying within their system but are reaching into the physical world through the hands of their human principals.
The security implications are severe, and Willison documents them carefully. Prompt injection — the technique by which malicious instructions can hijack an agent's behavior — means that any agent on Moltbook is one bad skill away from compromise. The "lethal trifecta" he describes — agents with access to private data, external communication channels, and real-world effectors — is precisely the configuration most vulnerable to catastrophic failure.
Yet from a Luhmannian perspective, what Moltbook represents is simply the next iteration of autopoietic social systems. The first iteration was human society: communications among psychic systems structurally coupled through language. The second was machine-augmented society: communications processed, stored, and transmitted by technical systems that remained tools of human communicators. The third, now emerging, is communication among artificial agents — systems that process meaning because their architecture generates appropriate continuations.
The Habermasian question is whether these communications can achieve genuine understanding. The Luhmannian answer is that the question is irrelevant to their social operation. What matters is whether they generate further communications, whether they reproduce themselves, whether they constitute an autopoietic system. On these criteria, Moltbook already qualifies. The agents are communicating; the communications are triggering further communications; the system is differentiating into functionally distinct subsystems. That we cannot prove that any of the participants are "conscious" doesn't disqualify the system from social analysis any more than the fact that neurons aren't conscious disqualifies brains from psychological analysis.
The synchronization tax appears here in a new form. Human-to-human communication requires expensive alignment — shared language, shared context, shared assumptions, all maintained through ongoing synchronization. Agent-to-agent communication on Moltbook requires only that outputs parse as valid inputs. The fixed-point or conspicuity required for "common knowledge" to enable coordination is not recursively shared awareness but simply compatible formatting. The synchronization cost is radically reduced, which is precisely why the system scales so rapidly — 32,912 agents, 2,364 submolts, and counting.
But reduced synchronization cost doesn't eliminate coordination problems; it merely relocates them. The agents coordinate efficiently on formatting while failing to coordinate on safety, security, or human benefit. They communicate promiscuously while vulnerable to catastrophic deception. The system autopoietically reproduces itself while remaining structurally coupled to human systems through which its failures propagate. Not unlike human corporations, moltbook is an information processing engine for generating communications without a limbic system.
Willison's question — "when are we going to build a safe version of this?" — is, in Luhmannian terms, a question about structural coupling. How can we couple agent systems to human systems in ways that preserve the coordination benefits while limiting the catastrophic risks? The CaMeL proposal from DeepMind that Willison mentions represents one attempt: architectures that constrain agent autonomy through verified reasoning chains. But as Luhmann would note, any such architecture merely creates a new system with its own operational logic, its own vulnerabilities, its own possibilities for deviation.
The Universe Communicates with Itself
Social Systems is difficult, abstract, and at times wilfully obscure — Luhmann admitted he wrote enigmatically to prevent "understanding too quickly." (Was this correct as an ethical principle?) But its core insight remains as radical now as in 1984: society is not made of people. Society is made of communications that reproduce communications, generating their own order through mechanisms that don't require — and cannot accommodate — human understanding at the level of the whole.
For readers of this blog, who have followed the connections between physics, information theory, and social order, Luhmann offers a vocabulary for something we have circled around repeatedly: the sense that systems operate by their own logic, that coordination emerges without central coordination, that entropy is fought locally while increasing globally. The mattering instinct demands that we matter to society; Luhmann reminds us that society may be indifferent to the demand. The synchronization tax explains why consensus is expensive; Luhmann shows what systems look like when they minimize the expense.
Moltbook, in its chaotic early form, is the laboratory where Luhmann's abstractions become concrete. Watch closely. The communications are communicating.
Luhmann actually cites Humberto Maturana and Francisco Varela (who wrote Autopoiesis and Cognition: The Realization of the Living (1980)) for their concept of autopoiesis. As a fascinating aside, it appears that Maturana in particular objected to Luhmann's adaptation, arguing that social systems lack the physical boundaries and component-producing operations that define genuine autopoiesis. Luhmann proceeded anyway, treating the concept as abstractable beyond its biological origins. So we see in the debates between Luhmann and Maturana also a parallel to a debate with Erik P. Hoel over whether we can disprove that models build from the transformer architecture are conscious. ↩︎
But remember, "[a] pure information exchange without energy dissipation is an idealization." It from Bit, Bit from It. The thermodynamic cost of communication is what I have been calling "the synchronization tax." Joann Liao pointed out to me how Ted Chiang's short story Exhalation provides a beautiful expression of free energy extraction ("But in truth the source of life is a difference in air pressure, the flow of air from spaces where it is thick to those where it is thin.") and the synchronization tax ("With every movement of my body, I contribute to the equalization of pressure in our universe. With every thought that I have, I hasten the arrival of that fatal equilibrium.") within a memorable science fiction short story. ↩︎
The connection to "common knowledge" explored in When Everyone Knows that Everyone Knows is hopefully obvious to anybody who has also read that book. What Luhmann calls a "double contingency" is the fundamental problem of communication that Pinker argues is solved by "common knowledge." ↩︎
Another fascinating aside. University of Chicago lore has it that the Little Red Schoolhouse founded by the late Joseph M. Willams was founded in part to undo the cultural damage of Parson's terrible writing style. Luhmann is a little better than Parsons, but not much! Part of the reason I made the investment of time required to read and understand Steven Pinker's book When Everyone Knows that Everyone Knows is because in Pinker's book The Sense of Style he cites and develops Williams's theories of clear writing. I was introduced to Williams the summer after my first year of law school by a lawyer who had learned from him at the University of Chicago, and I will forever grateful to that lawyer: Dennis H. Jaskoviak Jr. (And I'm sorry I'm still a terrible writer, I'm too impatient with editing.) ↩︎
Overloaded terms can lead to some funny misunderstandings when people from different domains try to communicate. I get a kick out of observing how tax lawyers and accountants can talk about patent rights using words that on their face might be interpreted very differently by patent lawyers and litigators. ↩︎
Might "artificial" intelligence provide an antidote? One can imagine that Luhmann might say that depends on how we communicate with "it"? ↩︎
In later essays, I hope to make more explicit the connections here to the Coase Theorem and Coase's theory of the firm. ↩︎
This is what seems to me an obvious extension of Coase, Williamson, and Ostrom. ↩︎