Maturana

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.

Testing the claims of Varela and Maturana via synthetic devices is the more serious concern in the discussion about Warwick and those involved in similar research.

That is, by describing social systems as operationally closed networks of communications, Luhmann (according to Maturana) ignores the fact that communications presuppose human communicators.