ABSTRACT
In 1991 Claus Emmeche and I suggested that ‘the chain of events which sets life apart from non-life.... needs at least two codes: one code for action (behaviour) and one code for memory—the very first of these codes necessarily must be analog and the second very probably must be digital.’ This principle of code-duality played a major role in our initial ideas on biosemiotics. The paper looks back to the origin of the idea of code-duality and confronts some of the ambiguities raised by the concept.