Writers often use the example of the brain to illustrate the concept of operational closure. Luhmann provides the example of consciousness. Consciousness is a closed system that operates only internally, something we should be grateful for because ‘…it would be terrible if someone could enter someone else’s consciousness and inject a few thoughts or a few perceptions of his own into it’.
Explaining how to understand operational closure in the context of social systems, Luhmann reminds us that the system is not to be understood as an ‘entity’, as a ‘unity’, but rather as a difference. The system is the difference between the system itself and its environment. Therefore, the question becomes who is drawing this distinction?
‘The distinction between system and environment is produced by the system itself. … [T]he important issue consists in the fact that the system draws its own boundaries by means of its own operations, that it thereby distinguishes itself from its environment, and that only then and in this manner can it be observed as a system.’
Operations within the system presuppose an environment. Luhmann speaks of ‘closure based on openness’ (and vice versa). That is, systems may be (and are) operationally closed but they are also cognitively open. To operate at all they are able to respond to stimuli from the environment. Nevertheless, any operation that occurs is located only within the system. The system relies exclusively on internal operations, therefore:
‘a system cannot use its own operations to get in touch with the environment. And this is precisely the point made by operational closure. Operations are from beginning to end (or, in other words, if seen as events) always possible only inside a system, and they cannot be used to make an intervention in the environment. For, in that case, when a border is crossed, they would have to become something other than system operations.’
It becomes clear that the concept of operational closure is best understood in tandem with those of autopoiesis, self-reference and, perhaps especially, constructivism – for which see here.
Luhmann, N. Introduction to Systems Theory (Cambridge: Polity Press, 2013) pp. 59-64.