Luhmann is called an “anti-humanist” not because he was against humans (he was not a misanthrope) but because he was against humanism; he was against taking the human being as the center of the universe. And Luhmann was not just a post-humanist because, for him, humanism was mistaken from the start.
In Niklas Luhmann’s Theory of Politics and Law, King and Thornhill write,
For Luhmann . . .the only meaningful form of rationality is ‘system rationality.’ He views rationality as a process of reflection situated outside the individual human being, and therefore, not limited to particular ‘structures of experience processing.’ Rationality is the operative self-organization of a system in its autonomous contingency and complexity. ‘A system acts rationally’, Luhmann explains, ‘to the extent that is can absorb complexity and can solve internal problems thrown up by this . . . to the extent that in an extremely complex world it can preserve a higher, more intelligible world, which excludes other possibilities.’
Rationality, conceived in this way, is not a specific human property, located in one consciousness or in the dialogical interstice between one person’s consciousness and that of another person. . . Instead, rationality is simply the internal reality of an effectively functioning social system. (134-35)
Rationality, by this definition, is not the same as cognition. According to Hans-Georg Moeller,
Luhmann uses [the term cognition] in a very broad sense. Cognition occurs not only in minds but in all kinds of systems: living systems (cells or immune systems can have cognition of enzymes or viruses), psychic systems (minds, of course, have cognition), and social systems (the news media, for instance, have cognition of foreign wars).
Observing systems are cognitive systems. If a system observes something, it has cognition. Cognition is always a construction by means of the operational possibilities of the system. The legal system cognizes everything in legal terms. These are not constituted by what is cognized, but by the system itself. Smoking in a restaurant is not legal or illegal as such. It only becomes legal or illegal in terms of the legal code.
Biologically speaking, how we see the world depends on the cognitive capacities of our eyes and brains to produce images. Cognition is always a construction by an observing system. (Luhmann Explained, 217-18)