The notion of "complexity" is a fundamental topic in the natural and social sciences and helps us to understand the relationship between systems and their environment. Niklas Luhmann traces a philosophical history of the concept showing how complexity indicates the possibility of describing unity (system, environment, world) referring mainly to the relationship between elements and relationships. The history of complexity also shows the path of modernity from medieval metaphysics to transcendental philosophy that rests on the investigation of subjective consciousness through a private self-reflection without the influence of the external world and religious determinations. However, the natural sciences offer interpretations that refer to the reduction of complexity based on structures that have selective functions and give rise to "emerging properties".
Above all, the sociological debate of the 60s and 70s highlighted the need to determine the elementary unity presupposed by complexity. The surveys were based on microsystems or even on the results of statistical data while from a philosophical point of view the problem of "sense" and its determined selection prevailed (Luhmann). In particular, we see a significant difference between the study of social systems and hermeneutics that privileges the interpretation of discursive practices. Selecting possibilities that contain a "sense" for the human being implies analyzing the nature and structure of the action in relation to the natural and social environment. Only through this investigation can we intervene to try to reduce the risks of a systemic evolution that escapes our control because it is guided by the imperatives of economic power that is threatening the planet with wars, the immoderate exploitation of resources and nature and the wrong use of artificial intelligence.
Placing the search for the unity of complexity in the very broad field of the theory of action leads to important differences especially between "strategic action", "instrumental action" and "communicative action". These differences are important because the action must always be studied in reference to specific purposes of the agent and to the social consequences (Habermas). Our philosophical contribution to the search for the unity of complexity for the human being, therefore without the reduction to natural properties of a science in particular, privileges the notion of "habitual behavior". Habits are both individual and social and lend themselves well to grasping the reduction of the complexity of human life and offer, according to a trans-disciplinary view, the normative assumptions to promote control over the choices we make with respect to the environment.
Provisional references:
N. Luhmann, Complessità sociale, Enciclopedia delle scienze sociali, online, 1992.
J. Habermas, Nachmetaphysisches Denken II, Frankfurt, Suhrkamp, 2012.
R. Giovagnoli, Habitual Behavior: Reduction of Complexity of Human Daily Life, in R. Giovagnoli & R. Lowe (Eds), The Logic of Social Practices II, Springer, Cham, 2023.