Since Saussure, the connection of an idea to a phonic pattern has been known as a 'sign'. In order to make the abstract form of this connection understandable to us, Saussure presents us with a visual representation: he draws a tree over the word 'tree' and separates the relation with a horizontal line. Around the diagram he draws an oval and adds two arrows which show that the reference is reversible. His approach illustrates the process of mise-en-scène in media societies that deal with signs of presence without having to having to use the abstraction of technologised practice. Saussure's diagram initialised a system of the scientific definition of the sign that then underwent further multi-variant development via French Structuralism. The collected lectures in this book trace the history of the problems and discourses of 20<sup>th</sup> century semiology – culminating in a return to action theory; as system theories, the structural positions of semiology again dissolve into action patterns, in order to scenically bridge the divide between cybernetic and sensual performances.
