The physical symbol system hypothesis, forst stated by Alan Newell in 1976, states that "a physical symbol system has the necessary and sufficient means for general intelligent action". A physical symbol system in this sense comprises a set of tokens or symbols with rules to manipulate them. In computer terms we can think of digital representatiosm, but the term can also be applied to physical tokens, as envisaged in Searle's Chinese room. It is related to notions of physicalism in the philosophy of intelligence and consciousness, but is sometimes given a tighter meaning assumes a higher-level symbol system as found in symbolic AI as opposed to subsymbolic neural networks; however the altter can be argued to also be manioulating 'symbols' on a broad sense of the term, just vast numbers of them.
Defined on page 8
Used on pages 8, 9, 10
Links:
ACM Digital Library: Computer science as empirical inquiry: symbols and search