Institute Professor Noam Chomsky of the Massachusetts Institute of Technology (MIT) is a towering figure in the field of linguistics, whose 1957 monograph, Syntactic Structures, has been ranked among the most influential publications in 20th century cognitive science. In addition, his work was cited more than any other living scholar from 1980 through 1992, and he has also been prolifically published, authoring more than 150 books.
On the top floor of MIT’s innovatively designed Stata Center, the Yale Scientific sat down with Chomsky to discuss his insights on fundamental issues facing both linguistics and the broader field of cognitive science.
Linguistics and the Minimalist Program
Chomsky’s basic research program, the field of generative grammar, posits that there exists a set of rules that can generate all grammatical sentences of natural language. Discovering such universal rules is highly challenging since they can be tested using grammatical sentences from any natural language as data. In this sense, generative grammar aspires to the same generality as theories in the physical and biological sciences.
In the early days of generative grammar, Chomsky focused on two types of grammatical rules – phrase structure rules, which are used, for instance, in assembling noun phrases and verb phrases, and transformational rules, which are used to explain movement of syntactic objects.
In the 1990s, Chomsky proposed his Minimalist Program, which focuses on economic principles in the design and structure of human language. The Minimalist Program involved a radical streamlining of the assumptions of generative grammar. The distinction between phrase-structure rules and transformational rules largely disappeared, and all syntactic structures were derived from a single operation. Chomsky explained that “the most elementary combinatorial operation which finds its place somewhere in every computational process is simply an operation that takes two objects already constructed and forms a new object out of them. That is what is called Merge.”
The Residue of a Historical Error
In discussing the minimalist program, Chomsky clarified a common misunderstanding pertaining to the displacement property of human language. The displacement property is the tendency for syntactic objects to have moved relative to the location dictated by basic phrase structure rules.
It was long thought that phrase-structure rules were more fundamental than transformational rules and thus, that the displacement property did not arise naturally from the most basic operations of language but rather had to be explained by additional principles. At one time, Chomsky considered this to be an imperfection of language; But Chomsky explained that this was “a residue of a historical error” and that with clarification, it was clear that displacement operations are just automatic. He added that other important properties of language follow if we simply assume that the language faculty is maximally efficient.
Fundamental Questions of Cognitive Science
When asked about the fundamental questions facing cognitive science, Chomsky addressed problems of interpretation, acquisition, and production. “As just one example, each of us has somehow acquired the capacity for language which, from the very first step, is largely mysterious. Take an infant. Almost instantly and reflexively, he or she is able to pick out of the environment, the datum which is language related. How? A chimpanzee has roughly the same auditory system but plainly it cannot. And that is just the first step that is still not understood. How did we get the capacity to produce and understand rather complex structures?”
Chomsky referred to this line of inquiry as the acquisition problem. He next defined the interpretation problem: “Given the environment around us, how do we construct in our minds our best guess about what the person is intending to say?” But Chomsky noted that the production problem is the most mysterious and daunting of all: how do we produce the complex structures that we generate?
Chomsky observed that this question has a long history. “As Descartes noticed, we appear to be speaking freely in a way that is appropriate to circumstances but not caused by the circumstances. So we can produce speech over an unbounded range, constantly innovating, in a way that is not determined by external stimuli and in a way that does not seem to be caused by any internal structure. And we do it in ways that others with similar capacities can comprehend and recognize as though they had thought the same way. Well that sort of creative aspect of comprehension is a total mystery. That is just language. But the same questions arise for everything else: vision, organization of motion, audition, arithmetical ability, painting, any cognitive act.”