Noam Chomsky (born Avram Noam Chomsky) grew up in Philadelphia surrounded by many intellectual trends. His neighborhood was a hotbed of the Hebrew language, Jewish culture, Zionism, and anarchist immigrants from Eastern Europe. Chomsky started his career at the intersection of many fields: philosophy, mathematics, biology, foreign language, traditional grammar, and linguistics. He wrote his thesis on the Morphophonology of Modern Hebrew and spent much of these early years between the University of Pennsylvania and Cambridge, Mass. One of the leading ideas of the day was BF Skinner’s behaviorism, which considered language a system of correct responses to stimuli. During language acquisition under behaviorism, correct responses are gradually reinforced positively until the language is internalized by the child. Chomsky wrote a scathing critique of this perspective and proposed Universal Grammar as an alternative.
The behaviorists believed that language was simply a list of sentences that could be memorized. There are obvious problems with this premise. Take for instance the recursive nature of language illustrated by these examples: I know him. -> She knows I know him. -> They know she knows I know him, etc. Under behaviorism, how can sentences be infinitely long? Another problem is the clear judgement native speakers have about the grammaticality of a sentence they’ve never heard before. The probability of the sentence “Colorless green ideas sleep furiously” being spontaneously uttered in real life is indistinguishable from zero. Yet every English speaker recognizes its structure as legal, even though neither it nor the context under which it could be uttered would ever occur if Chomsky hadn’t created it.
These ideas and more are explored in one of Chomsky’s most famous works, Syntactic Structures published in 1957 in the Hague. In it Chomsky describes two levels of language, the surface structure (SS) level which is observable, and the deep structure (DS) level, which is observed indirectly. To go from the DS to the SS in 1957, and for things like English wh-movement, one must apply transformations. In comparison to the anthropological linguists, Chomsky relied much more on mathematical forms of reasoning and traditional grammar.
Eventually Chomsky started a revolution. In addition to the general idea of Universal Grammar as a base framework for all language, Chomsky was responsible for paradigm shifts in every corner of the linguistic discipline. Some of these contributions are in phonology (generative phonology in The Sound Pattern of English), syntax (Government and Binding or X-bar theory AND the minimalist program), and morphology (nominalization in Remarks). His ideas on the whole seek to explain how surface structures are generated and to determine what deep universals exist.
Who lost in this revolution? Some of the losers include relativists who believed each language was an invention of a particular culture (like Whorf and other anthropological linguists), generative semanticists (who now mainly do Head-Driven Phrase Structure Grammar), and behaviorists.