Language [can] be expressed . . . by movements of the hands and face just as well as by the small, sound-generating movements of the throat and mouth. Then the first criterion for language that I had learned as a studentโit is spoken and heardโwas wrong; and, more important, language did not depend on our ability to speak and hear but must be a more abstract capacity of the brain. It was the brain that had language, and if that capacity was blocked in one channel, it would emerge through another.
Harlan Lane