The only scientifically interesting conception of a language is the I-language view

Chomsky therefore concludes that languages cannot be defined or individuated extensionally or mind-externally, and hence the only scientifically interesting conception of a ‘language’ is the ‘I-language’ view (see for example Chomsky 1986: 25; 1992; 1995 and elsewhere). Chomsky says of E-languages that “all scientific approaches have simply abandoned these elements of what is called ‘language’ in common usage” (Chomsky 1988, 37); and “we can define E-language in one way or another or not at all,