This paper will sketch a model of the human mind according to which the mind's structure is massively, but by no means wholly, modular. Modularity views in general will be motivated, elucidated, and defended, before the thesis of moderately massive modularity is explained and elaborated.

Modular models of mind

Many cognitive scientists and some philosophers now accept that the human mind is modular, in some sense and to some degree. There is much disagreement, however, concerning what a mental module actually is, and concerning the extent of the mind's modularity. Let us consider the latter controversy first.

How much modularity?

Here the existing literature contains a spectrum of opposed modularist positions. At one extreme is a sort of minimal peripheral-systems modularity, proposed and defended by Fodor (1983, 2000). This holds that there are a variety of modular input and output systems for cognition, including vision, audition, face-recognition, language-processing, and various motor-control systems. But on this view central cognition—the arena in which concepts are deployed, beliefs are formed, inferences drawn, and decisions made—is decidedly non-modular. Then at the other extreme is the hypothesis of massive modularity proposed and defended by evolutionary psychologists (Cosmides and Tooby, 1992, 1994; Tooby and Cosmides, 1992; Sperber, 1994, 1996; Pinker, 1997). This holds that the mind consists almost entirely of modular systems. On this view there is probably no such thing as ‘general learning’ at all, and all—or almost all—of the processes which generate beliefs, desires and decisions are modular in nature.