Noam Chomsky (1928-), professor of linguistics at Massachussetts Institute of Technology (and prominent political theorist), is one of the most cited living scholars. Chomsky was a major figure in the cognitive revolution which brought an end to the dominance of Skinnerian behavioral psychology and established cognitive models of human psychology and learning which remain central today. Chomsky replaced empiricist approaches with a mentalist or nativist theory of human learning based on the following observation about language:
The syntactical core of any language is so complicated and so specific in its form, so unlike other kinds of knowledge, that no child could learn it unless he already had the form of the grammar programmed into his brain, unless, that is, he had "perfect knowledge of a universal grammar.
Chomsky first formulated the logical problem of language acquisition, based on poverty of the stimulus arguments, and proposed a language acquisition device or Universal Grammar (UG) as a solution to this problem. Linguists working in this generative paradigm seek to describe human language in terms of highly abstract underlying structures; they are interested in our linguistic competence, or subconscious knowledge we all have about our language, rather than our performance, or actual use of language, which contains slips and errors. Milestones in the development of UG include Syntactic Structures (1957), Aspects of the theory of syntax (1965), the Principles and Parameters approach (1981), Government and Binding (1981) and The Minimalist Program (1995).