Aristotle and George Spencer-Brown

The paper deals with Aristotelian logic as the special case of more general epistemology and sociology of both science and common sense. The Aristotelian principles of identity, of noncontradiction, and of excluded middle are to be supplemented by the second-order cybernetic, or "cybernethic" principles of paradox, of ambivalence, and of control. In this paper we collect some ideas on how to evaluate the scope of Aristotelian logic with respect to the laws of thought they tried to determine and to do so within the historical moment of the impact of the invention of writing possibly triggering this determination. We look at some modern doubts concerning these laws and discovering an understanding of complexity that is not to be resumed under any principle of identity. The invention of sociology, epistemology, and the mathematics of communication follow suit in focusing not only on the observer but more importantly on the distinction between observers to further contextualize any talk of identities and operationalize both talk and fact of contradiction, paradox, and ambivalence.