The movie Don't Look Up illustrates the same systems theoretical basis when a comet approaches the Earth, different systems react differently and clash with one another: science, media, politics, and the economy the movie is a comedy and its humor is based on the incongruity between these systems.

The scientists want to communicate the scientific facts the media want to tell a good story, the big corporations want to make money, and the politicians want to have favorable polls. Each system does its own thing and people act in accordance with their roles in the respective system. This gives rise to multiple funny conflicts such as scientists being really awkward on TV shows. In the end, no centralized social action is possible, and while all the systems do what they do, and are busy dealing with one another, the comet destroys the Earth.

The question cannot be as manipulation theorists tend to ask "how can we get rid of media manipulation?" or as today's media discourses often suggest: let's abolish "fake news" so that only "true news" remain. This claim to replace fake with true news is of course also a media claim, and therefore "always already" both manipulated and manipulating. Luhmann writes: “It is impossible to understand the 'reality of the mass media'"

Functional differentiation has not always been there. According to Luhmann, it's the basic characteristic of modernity. Modern society is functionally differentiated.

The transition to functional differentiation happened---according to Luhmann--- between the 16th and the 18th century. Before that, society was characterized by what he calls “stratified differentiation”. This refers to different strata, roughly comparable to the different, hierarchical levels in feudal societies,

Like the aristocrats, the clerics, the craftspeople, and the farmers, or, if you prefer, it's also roughly comparable to what Marxists call “classes”. Before modernity, the differences between social strata structured life what people did or didn't do what they could and couldn't do depended on if they were, let's say, farmers or aristocrats. Today, what we do or don't do, what we can or can't do---when we study, vote, or watch YouTube, is conditioned by social systems like education, politics, or media.

Luhmann's most important concepts: "functional differentiation.”

This means the division of society into different systems. According to Luhmann, this is what Society consists of it's best understood not as a community of billions of individuals but at its basic level, it's constituted by these different systems.

This view of society can be roughly compared with the view of the human body not as a sum of cells or body parts like arms and legs, but is constituted by different systems such as cardiovascular system, the neural system, the reproductive system and so on. Social systems are defined by the function they fulfill for the whole. That's why Luhmann calls them “function systems”. Each of them allows society to do something in the body. For instance, the reproductive system enables humans to procreate in society, the political system for instance enabled society to make collectively binding decisions like joining the EU. If you want it or not, if the political system decides that your country joins the EU.

For Luhmann, [...] the most basic communication difference between the different systems is their code. This code is unique to each system. The legal system, for instance, is built around the code legal/illegal. All its communications, its institutions, its functions, revolve around this code. In the academic system (or “science system”), the basic code is true/not true. When academics publish a paper, or present a lecture, they tell others what they find to be true and not true. Others respond and contradict them but they must use the same code.

The purpose of the code is to enable the system to produce more and more communication, of the same type. It enables a system to respond to itself, to connect present with future communication and thereby to reproduce itself basically endlessly.

By using their codes, systems distinguish themselves from one another and achieve what Luhmann call “operational closure”. Communication of a system can only be continued with more communication of the same system. In academics, you respond to an academic paper with another paper, you cannot effectively respond with a song, or a prayer. If I just read out my academic papers here on this YouTube channel, no matter how brilliant they are, this channel would soon be dead.

Because of “operational closure”, we normally understand immediately to which system a communication operation belongs. If you give money to the waiter, it's understood it's the payment for your coffee, and not a declaration of love, or an encouragement to vote for you in the upcoming elections.

Niklas Luhmann aims at providing a higher level media theory than the manipulation theories, which flourish in both popular and academic circles. He recognizes that manipulation is not something external that happens to media from the outside and that could or should be avoided, instead it's an internal characteristic of how media work. Mass media cannot not be manipulated.

Luhmann presents not just the theory of the mass media, but a grand super theory of society. For him the mass media is just one of many autonomous systems all administered by their respective codes.

Crucially, Luhmann calls himself a “radical constructivist”. For him social reality, like money in the economy or points in sports, is constructed. But constructivism is no anti-realism. Something is real not despite but because it's constructed, like this video, for instance. Just as economic value is constructed in the economy, or political power in politics, “truth” is constructed in science or academics. [...] his does not mean that it is not valid, to the contrary For truth to be really valid, it must be constructed in science—and not, as in the past, prior to functional differentiation, by the Pope.