[...] Chomsky saw--and this, I believe, has been his most penetrating insight--that a valid model of linguistic behavior must account for the extraordariny fact that all of us perpetually and effortlessly use strings and combinations of words which we have never heard before, which we have never been taught specifically, and which quite obviously do not arise in conditioned response to any identifiable stimulus in our environment. Almost from the earliest stages of his linguistic life, a child will be able to construct and to understand a fantastic number of utterances that are quite new to him yet that he somehow knows to be acceptable sentences in his language. Conversely, he will quickly demonstrate his instinctive rejection of (that is, his failure to grasp) word orders and syntactic arrangements that are unacceptable though it may be that none of these have been specifically pointed out to him. At every stage, from earliest childhood on, the human use of language goes far beyond all "taught" or formal precedent, and far beyond the aggregate of individually acquired and stored experience. "These abilities", says Chomsky, "indicate that there must be fundamental processes at work quite independently of 'feedback' from the environment." The dynamics of human communication arise from within.