How did Noam Chomsky’s approach differ from Zellig S. Harris’s structural linguistics?

While Zellig S. Harris and Noam Chomsky both contributed to the development of transformational grammar, their approaches were distinct in context and purpose.21

Harris, a structuralist, focused on extending the methods of Leonard Bloomfield to discover the linear distributional relations of phonemes and morphemes. For Harris, a transformation was a descriptive tool used to relate surface-level sentence forms, rather than a mechanism for deriving surface structures from a deeper level.1

In contrast, Chomsky’s system, as presented in Syntactic Structures, was a reaction against the post-Bloomfieldian emphasis on "discovery procedures." Instead of focusing on how descriptions were arrived at, Chomsky sought to formulate criteria for evaluating alternative grammars using formal, mathematical notions. His approach differed significantly in the following ways:2

• Mentalism: Chomsky adopted a "mentalistic" theory, prioritizing the speaker’s creative linguistic competence over the observation of actual performance.2
• Deep Structure: He introduced the concept of deep structure as an underlying level of representation from which meaning is derived, a departure from Harris’s surface-oriented analysis.23
• Universals: Chomsky challenged the structuralist view that every language is unique, arguing instead that languages share formal and substantive universals.2