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.