This post is admittedly ambitious. It won't be long or super technical, but it will discuss what I view as Chomsky's largest error in thinking on language. I am currently reading his book On Language, which is a series of interview responses and talks that he gave over a long period of time. The following passage is what struck me most while reading the book.
But human cognitive systems, when seriously investigated, prove to be no less marvelous and intricate than the physical structures that develop in the life of the organism. Why, then, should we not study the acquisition of a cognitive structure such as language more or less as we study some complex bodily organ?
This above passage is the central issue I have with his way of thinking. I agree with Chomsky that the acquisition of cognitive structures should be studied in the same way we study the acquisition of bodily structures like organs. However, I completely disagree that language is a cognitive structure, unless I misunderstand his meaning of cognitive structure.
Bodily structures such as muscles and organs develop in a predetermined way constrained by our genetics. We all develop a heart or skeleton regardless of the small variations. This development is genetically predetermined. We cannot will ourselves to grow wings or scales.
However, how we use these structures is willed. We can move in an infinite number of ways, none of which are genetically predetermined. Of course, these willed movements are constrained, due to our physical structures determined by genetics. We cannot fly, because we do not have wings. We cannot swim like a fish, because we do not have gills. We rely on our genetically determined physical structures to move in an infinite number of new and novel ways, even without any prior experience. We do not have to see someone else jump onto our couch to do so ourselves. We can do this because of the mix of our past genetically developed physical structures and environmentally developed adaptations of those structures.
This is fundamentally true of language as well. Language is analogous to movement, not bodily structures. It is the coordination of our past genetically developed cognitive structures and environmentally developed adaptations of those structures that allow novel language.
Language is equivalent to the idea of movement which relies on structures, not the structures themselves.
Chomsky's largest disagreement with the behaviorist notions of language was the fact that they could not explain novel sentences generated from the "limited and impoverished experience" that people have throughout life. This is not a problem from my viewpoint. People do not wonder how children are able to produce novel movements from their "limited and impoverished experiences". They develop their physiological structures that develop through adaptation to their environment in a genetically constrained way. These developments and adaptations of their bones, muscles, tendons, etc. allow them to employ those same physical structures in novel ways without relying on past experience to do so.
Chomsky seems to believe that language is a structure that develops, like a heart or lung, and then wonders how it is possible to use those organs in novel ways. This is incorrect. We don't use our organs in novel ways. We use our organs to express novel movement, just as we use our brain's structure and past experiences to express novel language.