_An Essay on Man_, Cassirer. Bantam Books, NY, January 1970. Part I: What is Man? Chapter II: A Clue to the Nature of Man: the Symbol. pp. 25 – 28. As demonstrated by the biologist Johannes von Uexk ü ll, life must be understood not in terms of physics and chemistry, but as a distinct and self-subsisting actuality which takes on innumerable forms, each of which constitutes a unique mode of experience and, therefore, possesses a unique reality. The circular operation and interaction of anatomically identifiable receptor (Recall Gro ß ' “attention economy”) and effector systems, which determines and coordinates the environmental stimuli that affect the organism and its response to those stimuli, characterizes all life including human life. But, while this “functional circle” ( Uexk ü ll) forms a direct and immediate type of experience for animals, the receptor and effector systems are separated by a symbolic system in human life. This interposition of the symbol de...