• Sociologist Niklas Luhmann, 1927
  

Luhmann was born in Lüneburg, Lower Saxony, where his father's family had been running a brewery for several generations. After graduating from the Johanneum school in 1943, he was conscripted as a Luftwaffenhelfer in World War II and served for two years until, at the age of 17, he was taken prisoner of war by American troops in 1945. After the war Luhmann studied law at the University of Freiburg from 1946 to 1949, when he obtained a law degree, and then began a career in Lüneburg's public administration. During a sabbatical in 1961, he went to Harvard, where he met and studied under Talcott Parsons, then the world's most influential social systems theorist.

In later years, Luhmann dismissed Parsons' theory, developing a rival approach of his own. Leaving the civil service in 1962, he lectured at the national Deutsche Hochschule für Verwaltungswissenschaften (University for Administrative Sciences) in Speyer, Germany, until 1965, when he was offered a position at the Sozialforschungsstelle (Social Research Centre) of the University of Münster, led by Helmut Schelsky. 1965/66 he studied one semester of sociology at the University of Münster.

Two earlier books were retroactively accepted as a PhD thesis and habilitation at the University of Münster in 1966, qualifying him for a university professorship. In 1968/1969, he briefly served as a lecturer at Theodor Adorno's former chair at the University of Frankfurt and then was appointed full professor of sociology at the newly founded University of Bielefeld, Germany (until 1993). He continued to publish after his retirement, when he finally found the time to complete his magnum opus, Die Gesellschaft der Gesellschaft ("Society as a Social System"), which was published in 1997.

Luhmann wrote prolifically, with more than 70 books and nearly 400 scholarly articles published on a variety of subjects, including law, economy, politics, art, religion, ecology, mass media, and love. While his theories have yet to make a major mark in American sociology, his theory is currently well known and popular in German sociology, and has also been rather intensively received in Japan and Eastern Europe, including Russia. His relatively low profile elsewhere is partly due to the fact that translating his work is a difficult task, since his writing presents a challenge even to readers of German, including many sociologists.

Much of Luhmann's work directly deals with the operations of the legal system and his autopoietic theory of law is regarded as one of the more influential contributions to the sociology of law and socio - legal studies.

Luhmann is probably best known to North Americans for his debate with the critical theorist Jürgen Habermas over the potential of social systems theory. Like his one time mentor Talcott Parsons, Luhmann is an advocate of "grand theory," although neither in the sense of philosophical foundationalism nor in the sense of "meta - narrative" as often invoked in the critical works of post-modernist writers. Rather, Luhmann's work tracks closer to complexity theory broadly speaking, in that it aims to address any aspect of social life within a universal theoretical framework - of which the diversity of subjects he wrote about is an indication. Luhmann's theory is generally considered highly abstract, and his publications are difficult to read. This fact, along with the somewhat elitist behavior of some of his disciples and the supposed political conservatism implicit in his theory, has made Luhmann a controversial figure in sociology.

A major critique of Luhmann is found in Piyush Mathur's detailed exegesis (2006) of one of Luhmann's treatises in an American journal. Luhmann himself described his theory as "labyrinth - like" or "non - linear" and claimed he was deliberately keeping his prose enigmatic to prevent it from being understood "too quickly", which would only produce simplistic misunderstandings. The influence of Gregory Bateson and Jurgen Ruesch on Luhmann has been discussed by Piyush Mathur in an April 2008 article titled Gregory Bateson, Niklas Luhmann, and Ecological Communication.

Luhmann's systems theory focuses on three topics, which are interconnected in his entire work.

1. Systems theory as societal theory;
2. Communication theory;
3. Evolution theory.

The core element of Luhmann's theory is communication. Social systems are systems of communication, and society is the most encompassing social system. Being the social system that comprises all (and only) communication, today's society is a world society. A system is defined by a boundary between itself and its environment, dividing it from an infinitely complex, or (colloquially) chaotic, exterior. The interior of the system is thus a zone of reduced complexity: Communication within a system operates by selecting only a limited amount of all information available outside. This process is also called "reduction of complexity." The criterion according to which information is selected and processed is meaning (in German, Sinn). Both social systems and psychical or personal systems (see below for an explanation of this distinction) operate by processing meaning.

Furthermore, each system has a distinctive identity that is constantly reproduced in its communication and depends on what is considered meaningful and what is not. If a system fails to maintain that identity, it ceases to exist as a system and dissolves back into the environment it emerged from. Luhmann called this process of reproduction from elements previously filtered from an over - complex environment autopoiesis (pronounced "auto - poy - E - sis"; literally: self - creation), using a term coined in cognitive biology by Chilean thinkers Humberto Maturana and Francisco Varela. Social systems are autopoietically closed in that while they use and rely on resources from their environment, those resources do not become part of the systems' operation. Both thought and digestion are important preconditions for communication, but neither appears in communication as such.

Luhmann likens the operation of autopoiesis (the filtering and processing of information from the environment) to a program, making a series of logical distinctions (in German, Unterscheidungen). Here, Luhmann refers to the British mathematician G. Spencer - Brown's logic of distinctions that Maturana and Varela had earlier identified as a model for the functioning of any cognitive process. The supreme criterion guiding the "self - creation" of any given system is a defining binary code. This binary code, is not to be confused with the computers operation: Luhmann (following Spencer - Brown and Gregory Bateson) assumes that auto - referential systems are continuously confronted with the dilemma of disintegration / continuation. This dilemma is framed with an ever - changing set of available choices; everyone of those potential choices can be the system's selection or not (a binary state, selected / rejected). The influence of Spencer - Brown's book, Laws of Form, on Luhmann can hardly be overestimated.

Although Luhmann first developed his understanding of social systems theory under Parsons' influence, he soon moved away from the Parsonian concept. The most important difference is that Parsons used systems merely as an analytic tool to understand certain processes going on in society; Luhmann, in contrast, treats his vision of systems ontologically, saying that "systems exist". That is, Luhmann in fact suggests to substitute the paradigm of systems theory for the ontological paradigm: the difference system/environment (which also signifies a relationship).

Another difference is that Parsons asks how certain subsystems contribute to the functioning of overall society. Luhmann starts with the differentiation of the systems themselves out of a nondescript environment. He does observe how certain systems fulfill functions that contribute to "society" as a whole, but this is happening more or less by chance, without an overarching vision of society. Finally, the systems' autopoietic closure is another fundamental difference from Parsons' concept. Each system works strictly according to its very own code and has no understanding at all of the way other systems perceive their environment. For example, the economy is all about money, so there is no independent role in the economic system for extraneous aspects such as morals.

One seemingly peculiar, but within the overall framework strictly logical, axiom of Luhmann's theory is the human being's position outside any social system, initially developed by Parsons. Consisting of "pure communicative actions" (a reference to Jürgen Habermas) any social system requires human consciousnesses (personal or psychical systems) as an obviously necessary, but nevertheless environmental resource. In Luhmann's terms, human beings are neither part of society nor of any specific systems, just as they are not part of a conversation. Luhmann himself once said concisely that he was "not interested in people". That is not to say that people were not a matter for Luhmann, but rather, the communicative actions of people are constituted (but not defined) by society, and society is constituted (but not defined) by the communicative actions of people: society is people's environment, and people are society's environment. Thus, sociology can explain how persons can change society; the influence of the environment (the people) on the system (the society), the so-called “structural coupling”. In fact Luhmann himself replied to the relevant criticism by stating that "In fact the theory of autopoietic systems could bear the title Taking Individuals Seriously, certainly more seriously than our humanistic tradition" (Niklas Luhmann, Operational Closure and Structural Coupling: The Differentiation of the Legal System, Cardozo Law Review, vol. 13: 1422)

Luhmann was devoted to the ideal of non - normative science introduced to sociology in the early 20th century by Max Weber and later re-defined and defended against its critics by Karl Popper. However, in an academic environment that never strictly separated descriptive and normative theories of society, Luhmann's sociology has widely attracted criticism from various intellectuals, perhaps most notably from Jürgen Habermas.

Luhmann also appears as a character in Paul Wühr's work of literature Das falsche Buch, together with - among others - Ulrich Sonnemann, Johann Georg Hamann and Richard Buckminster Fuller.

Luhmann owned a pub ("Pons") in his parents' house in his native town of Lüneburg. The house, which also contained his father's brewery, had been in his family's hands since 1857.