The concept of autopoiesis in itself cannot explain a system’s persistence over time. Autopoiesis happens in a moment; it is an event that passes away as soon as it occurs and must be replaced with another operation. But in order for systems to persist or reproduce themselves, structures must emerge. Only structures persist in time. Thus structural coupling complements autopoiesis. Structure is associated with redundancy--repetition of the same kind of event. Systems recognize the same kinds of event and they develop expectations. Social structures are actually expectations.
Luhmann borrowed the structurally coupling concept from from Humberto Maturana. As Luhmann writes,
Maturana introduced the concept of structural coupling. The distinction [between this concept and autopoiesis] allows us to say that autopoiesis must function in any case since there would otherwise be no system. At the same time, it also indicates that coupling between system and environment concerns only structures [and not operations] and, as the case may be, everything in the environment that is relevant to these structures. Thus, on earth gravity is coordinated with the musculature of a living being that has to move in order to survive. . . . This is a case of structural coupling. This concept is adjusted to the autopoiesis of the system, which is to say that structural coupling does not interfere with the system’s autopoiesis [my emphasis]. . . There [can be] the destruction of the system by the environment, but the environment does not actively contribute to the maintenance of the system. This is precisely the point of the concept of ‘autopoiesis.’ The causalities that occur between system and environment are located exclusively in the domain of structural coupling. (Introduction to Systems Theory, 85)
In other words, nothing in a system’s environment can cause a specific structural change, or change of state, to happen in the system. The environment can only perturb or destabilize a system, but the system restabilizes itself in its own way.
Simultaneous Dependence and and Exclusion
Luhmann speaks of a simultaneous dependence and exclusion in structural coupling. For instance, the meaning attributed (by society) to a sentence cannot depend on what the speaker was thinking or intending when she spoke the sentence. This means that communication is not bound by consciousness, as in the intentions or desires of a speaker. And with respect to organic systems, while a person has to be alive to make an utterance (which could include talking in one’s sleep), the meaning of an utterance, clearly, doesn’t depend on the blood pressure or cholesterol numbers or any other elements of the speaker’s body. The point is that communication system simply cannot be concerned with all that. As Luhmann puts it,
After all, it is completely unthinkable that communication would have to consider everything that happens physically, chemically, or biologically within all the participants of communication. (Introduction to Systems Theory, 199).
All of that is excluded from communication. Something like cholesterol levels can only be included in a communication system as a topic; that is, it has to be translated into language.
In order to engage in language-based communication, one must be awake and attending to language. This is a case of structural coupling between a communication system and a consciousness/attention system, also known as the psychic system. Communication depends fundamentally on consciousness, or the conscious awareness; however, consciousness is operationally excluded from the communication system. In other words, communication is structurally coupled to consciousness, but not operationally coupled.
Operational coupling can happen when two systems have access the same operation, which means that the different, autonomous systems must be subsystems of the same system. For example, the healthcare (or medical) system and the education system are both subsystems of society. And these two subsystems can operationally couple when, for example, a doctor writes a note excusing a patient from school. It is the written communication from doctor to school that constitutes operational coupling. Both systems, being subsystems of society, have access to communication. However, it’s important to understand that the writing of the note alone is not enough; the note must be read and understood (or even misunderstood) by the school in order to count as communication–and the note must be understood as educationally relevant or meaningful, not medically meaningful. Communication is a system operation, not the act of a single person–it’s not a “speech act,” and it doesn’t depend on intent to communicate. A spy, for instance, can pick up communication that isn’t intended, or a slip of the tongue can be meaningfully understood.
In the example of the doctor and the note, we have a single person who is observed (by the medical system and the education system) as both a patient and a student. We might say she is “counted” by both systems; however, she is not a part of either system, because systems are not wholes consisting of parts. The elements of these systems are communication events, not people.
It’s important to understand that when two autonomous systems (e.g., two psychic systems or two different function systems) structurally couple, there is not a third system that emerges through combination. That is to say, contrary to some sociological theory, the two systems are not integrated. Two or more psychic systems cannot share the same thoughts, feelings, or perceptions. And the political system and the economic system do structurally couple, but they cannot form a third function system that combines the functions of politics and economics. That is to say, there is no third system that contains economy and politics as parts. A third system would cause the two systems to “stick together” and so their autonomy. If the economy collapsed, the political system would collapse with it–and vice versa.
When a state, as an organizational system, spends money, it structurally couples politics and the economy. Also when it passes a law regulating an economic practice, it structurally couples law and the economy. Nonetheless, these functional systems remain distinct, and the regulation can be subverted by the economy.
Systems can be structurally coupled loosely or tightly, and , given how much money states raise and spend, modern politics and economics (where the welfare state comes into being) are very tightly coupled. Tightly coupled systems tend to perturb one another a great deal. For instance, an economic recession can perturb the state so that they governing party may lose power to the opposition. Or unwise fiscal decisions of a government can perturb the economy and prompt it to restabilize itself.
A case of loose structurally coupling in modern society would be the coupling between religion and politics. It is unlikely that a change in religious doctrine could significantly destabilize a modern state, and it is unlikely that a government decision could significantly destabilize religion. Which is why the framers of modern constitutional republics took such pains to keep these two politics and religion apart. They didn’t want religious wars that could destroy the political system.
As for psychic systems, consciousness attends to its environment, which can be sensory impressions arising from within the body (e.g., a racing heart, a fever, a stomach ache) or external objects and events (i.e., anything seen, heard, felt, or tasted). And with internalized language, the psychic system can think about these perceptions, and, of course, think about thoughts. In this case, the psychic system uses the social medium of language for its own, nonsocial purposes.
And, according to Luhmann, actions like jumping up and down and shouting after accidentally striking one’s thumb with a hammer don’t count as language. Those inarticulate actions would have to be reframed with language before they could enter society, as when an adult tries to explain why child is crying or throwing a tantrum. The actions have to be interpreted.
The main point here is that consciousness is completely excluded from the operation of communication. This is what it means to say that autopoietic systems are operationally closed. Consciousness structurally couples with communication, but consciousness is excluded from the operation of communication; that is to say, consciousness must remain in the environment of the communication system. This is good for consciousness because if communication fails consciousness does cease its operations. Helen Keller didn’t lack consciousness before she learned to communicate.
Consciousness must be structurally coupled to the biological systems of the body. For instance, there can be no consciousness without adequate cerebral blood flow; that is to say, a person cannot attend to or process sensory impressions without a functioning brain. However, the brain is operationally excluded from consciousness. If this wasn’t the case, when a person went to sleep the brain would die. And clearly the brain would die if a person entered a long-term coma. That is to say, brain function does not depend on consciousness, yet consciousness does depend on the brain. This is an asymmetrical relationship.
Even though consciousness directly depends on adequate cerebral blood flow, communication does not. Communication depends only indirectly on the functioning brain. Communication directly depends only on consciousness, and consciousness directly depends only on a functioning brain. So consciousness stands between communication and the brain, so to speak. Cerebral blood flow is operationally excluded from the communication system. In other words, the only operation communication can link up with is communication.
Structural Coupling and Uncoupling
Another way of putting this (if yet another way is needed!) is that structural coupling implies structural decoupling. If communication can structurally couple with consciousness, it must also be able to decouple; otherwise the two systems would be one. For instance, sentences spoken or written can remain in a communication system as long as they are repeated or recur in further communication. The “original” speakers and listeners (or writers and readers) can be long dead, but the communication can remain in circulation. It’s true that some human consciousness has to be around to keep the sentence in communicative circulation; however, human consciousnesses (attentive minds) are plentiful and easily replaced. Thus, Luhmann can say that
communication depends completely on consciousness and at the same time excludes it completely. (Intro 199)
A system’s structures are influenced (but never directly steered) by conditions in its environment. Something in the system’s environment can certainly destroy a system (if, for instance a boulder crushes a person or if an asteroid crashes into a planet), but it cannot directly change it in any other way. In other words, there is a not a simple input-output process as in trivial machines. In complex machines, like societies, the “output” cannot be precisely predicted by the “input.” This means that a human being, or any complex organism, does not operate according to simple behaviorist stimulus-response models. In brief, the effect of a particular stimulus on a system depends on the system’s own structures. The operations are structurally determined.
An example a trivial machine is the the equation 2x=y. If I know what x is, I will know what y is. But if two students in a literature class read the same novel (the same “input”), the essays they write (the “output”) will obviously not be identical (unless one has plagiarized the other!) because the students do not have the same cognitive or affective structures.
So, after all this work, what is gained by excluding everything except except consciousness from the possibility of structurally coupling with communication? What is the evolutionary compensation?
What is gained is that communication has to depend on one and only one thing in its environment; it only has to depend on consciousness. Consciousness, in turn, only has to depend on organic systems of the body. This simplifies matters quite a bit. Communication doesn’t have to directly depend on a properly functioning brain or heart because consciousness depends on all that. If these organic preconditions aren’t met, then there is no question of communication anyway; so why worry about it or try to control it? As Luhmann puts it,
The compensation for this exclusion is the total dependence of communication on consciousness, which in turn depends completely on one’s brain, and the brain requires that the organism be alive. . . . [This is a] paradox of simultaneous total dependence and total independence. Communication happens only via consciousness and with the help of consciousness but never operationally as consciousness. (Introduction to Systems Theory, 200-201).