ABSTRACT
A foundational principle of modem cognitive science is the physical symbol system hypothesis, which states simply that human cognition is the product of a physical symbol system (PSS). A symbol is a pattern that denotes something else; a symbol system is a set of symbols that can be composed into more complex structures by a set of relations. The term physical conveys that a symbol system can and must be realized in some physical way to create intelligence. The physical basis may be the circuits of an electronic computer, the neural substrate of a thinking biological organism, or in principle anything else that can implement a Turing machine-like computing device. Classical presentations of the PSS hypothesis include Newell and Simon (1976) and Newell (1980); more recent discussions include Newell (1990) and Vera and Simon (1993, 1994).
