An approach informed by the modular theory of mind. This theory, associated in particular with formal linguistics, is also explored in other areas of cognitive science such as philosophy and cognitive psychology. It holds that the human mind is organised into distinct 'encapsulated' modules of knowledge, one of which is language, and that these modules serve to 'digest' raw sensory input in such a way that it can then be processed by the central cognitive system (involving deduction, reasoning, memory and so on). Cognitive linguists specifically reject the claim that there is a distinct language module.

The claim that language is an encapsulated module amounts to the assertion that linguistic structure and organisation are markedly distinct from other aspects of cognition. From the perspective of formal linguistics, this theory entails that language can be studied independently of other aspects of cognitive function.

Moreover, formal linguists also treat language itself as modular. Thus the various 'knowledge systems' that make up linguistic knowledge, including phonology, semantics and syntax, are encapsulated sub-modules of the language module. Accordingly, they too can be studied independently of one another as they are held to be structured in wholly distinct ways. Cognitive linguists also reject the claim that language consists of wholly distinct sub-modules.