1.

H. Maturana formulates pragmatically in short: "An observer is a human being, a person, someone who can make distinctions and indicate precisely what he considers to be an entity (something) different from himself, who can do this with regard to his own actions and thoughts in a recursive way, and who is always able to do all this as if he were outside (or separated from) the given situation" (Erkennen:139). In this way he limits the observer to human beings, but he also gives him many connotations that can lead to misunderstandings. N. Luhmann tries to avoid these misunderstandings. With his suggestions to use "consciousness" or "psychic system" instead of "human being", I would go out of the frying pan into the fire (see also Anm 2 zu Ausage), and I would also abandon the theory of social systems.

2.

Initially, systems theory spoke of an "outside observer", a scientist who models a system. H. Maturana then only spoke of the "observer". With his (trivial) postulate that "every statement comes from an observer" (1982:34 and 148), which hit science like a bomb in 1970, he not only introduced the observer instance by name, but also produced a linguistic complication, because he receptively described the activity of the scientist as observing instead of productively constructing. It makes sense that H. Maturana is often counted among the constructivists.
N. Luhmann has retained the expression, but explicitly for an active operation that ends in (linguistic) naming. N. Luhmann says in reference to G. Spencer-Brown, observe hot "differentiate and name", which is a somewhat strange explication, because naming implies differentiation, which N. Luhmann calls re-entry.

H. Maturana says: "Every statement comes from an observer". I also say: "All observers can make statements". H. Maturana determines what he allows as a statement, I determine what I allow as an observer. As an observer, in this terminological sense, one can always imagine an arbitrarily abstract being that can just about make statements. Abstraction is often overstretched, so that institutions and organizations such as families or companies, "functional systems" such as art, religion, societies, etc. are included, which express their speech through specific organisms, which are then called role bearers, for example. If a spokesperson belongs to the company, one can say in this metaphorical sense that the company speaks where he speaks.

Jurisprudence and the morality behind it reflects the insignificance of people in social systems. Therefore, the company spokesperson does not become responsible when speaking in place of the company. Of course, the practice is arbitrary. Often - as in Greek mythology - the messengers of the message are judged, such as the GDR soldiers who shot at refugees at the wall in the name of their fatherland.

N. Luhmann finds it uninteresting who is speaking (except, of course, in the case of monetary copy "rights"), in his case it speaks through the author, whereby it does not matter whose thoughts the author expresses, what exactly the meaning of the expression author is. In the sociological systems theory of N. Luhmann, the question of the observer is not asked, because paradoxes are attributed communicative potential. The question there is which distinctions underlie an observation, but not who makes the observation. The part of G. Spencer-Brown's calculus of form to which N. Luhmann refers serves to dissolve paradoxes.

Paradoxes, of course, only arise when the observer is left out. If I make the observer disappear completely - for the sake of objectivity - Zeno's paradoxes arise, and if I fade out the observer as an observer, the Cretan paradox arises. The paradoxes disappear when I introduce the observer, that is, when I say who perceives which phenomena in which perspective (cf. Todesco, R: Lügen alle Kreter? (Do all Cretans lie?)).

The sociological systems theory of N. Luhmann can be interpreted discursively (in the sense of M. Foucault) from this point of view: The observer is specifically tabooed, so that a discourse of truth, which is suspended by contingencies, becomes possible. M. Foucault has placed the Victorian tabooing of sexuality in the function of creating knowledge. The tabooing of the observer enables a normality of social conditions.