Overview

This chapter focuses on one of the most powerful ideas in cognitive science. This is the analogy between minds and digital computers. In the early days of cognitive science this analogy was one of cognitive science's defining ideas. As emerged in the historical overview in Part I, cognitive science has evolved in a number of important ways and what is often called the computational theory of mind is no longer “the only game in town.” Yet the computational theory, and the model of information processing on which it is built, still commands widespread support among cognitive scientists. In this chapter we see why.

For a very general expression of the analogy between minds and computers we can turn to the physical symbol system hypothesis, proposed in 1975 by the computer scientists Herbert Simon and Allen Newell. According to this hypothesis, all intelligent behavior essentially involves transforming physical symbols according to rules. Section 6.1 spells out how this very general idea is to be understood. Newell and Simon proposed the physical symbol system hypothesis in a very programmatic way. It is more of a general blueprint than a concrete proposal about how the mind processes information. And so in section 6.2 we turn to the version of the physical symbol system hypothesis developed by the philosopher Jerry Fodor. Fodor develops a subtle and sophisticated argument for why symbolic information processing has to be linguistic. He argues that the architecture of the mind is built around a language of thought.