Where George Spencer-Brown went wrong – re-entry recalculated

Abstract

Purpose: The paper uncovers a mathematical error in George Spencer-Brown's genesis of re-entry. It distinguishes between the two interpretations of re-entry presented in “Laws of Form”: recursive versus sequential. The Indeterminacy inferred by George Spencer-Brown from his recursive genesis of re-entry is refuted in three different ways. The calculation of the Modulator from “Laws of Form” demonstrates that only the sequential interpretation of re-entry is reasonable. This contributes to the demystification of re-entry and enables a deeper understanding. Finally, six differences between the concept of form from “Laws of Form” and Niklas Luhmann's sociological systems theory are presented. Design/methodology/approach: Methodologically, the paper uses the ternary logic of discrete mathematics, which extends {0, 1} by “don't care” to {0, 1, -}. George Spencer-Brown's Indeterminicy is refuted by using three different methods: complete induction, Theorems 14 and 15 and the software XBOOLE. For the calculation of the Modulator, the only practical application of re-entry in “Laws of Form”, techniques from automata theory are used. Findings: The paper reveals a mathematical error in George Spencer-Brown's genesis of the re-entry of “Laws of Form” and refutes the assumption of Indeterminicy. The analysis of the only practical application of re-entry presented by George Spencer-Brown shows that the functioning of this Modulator can only be described correctly with the sequential interpretation of re-entry. Originality/value: The paper emphasizes the interdisciplinary potential of sociology and information technology and provides methods and tools of discrete mathematics for use in the analysis of the works of George Spencer-Brown and Niklas Luhmann.