Full Idea
We need to postulate a network of beliefs, and also a background of capacities that are not themselves part of the network.
Gist of Idea
Beliefs are part of a network, and also exist against a background
Source
John Searle (The Rediscovery of the Mind [1992], Ch. 8.I)
Book Reference
Searle,John R.: 'The Rediscovery of the Mind' [MIT 1999], p.176