Reflections on Language

The principles of human language acquisition can be seen as a "learning theory", and, while "we lack an interesting conception" of almost all perceivable learning theories, "there are, I believe, some substantive steps towards [the learning theory of human language], but nothing comparable in other domains of human learning" (p. 19). "Let us define 'universal grammar' (UG) as the system of principles, conditions and rues that are elements or properties of all human languages not merely by accident but by [biological] necessity ... Thus UG can be taken as expressing 'the essence of human language.' ... UG will specify what language learning must achieve, if it takes place successfully. Thus UG will be a significant component of [the learning theory of human language] ... We can gain some insight into UG ... whenever we find properties of language that can reasonably be supposed not to have been learned." (pp. 29-30). The following is one such piece of UG. One may turn declarations into questions by moving the "is" in front, e.g. "the man is tall" becomes "is the man tall". But consider now the statement "the man who is tall is in the room". If language was nothing but a social construction then it would be perfectly reasonable for children trying to form the corresponding question to say "is the man who tall is in the room" in analogy with the above. However, "children make many mistakes in language learning, but never mistakes such as [this]" (p. 31). Apparently, "the child is employing a 'structure-dependent rule'" rather than the much simpler rule to put the first "is" in front. Why? "There seems to be no explanation in terms of 'communicative efficiency' or similar considerations. It is certainly absurd to argue that children are trained to use the structure-dependent rule, in this case ... The only reasonable conclusion is that UG contains the principle that all such rules must be structure-dependent. That is, the child's mind ... contains the instruction: Construct a structure-dependent rule, ignoring all structure-independent rules." (pp. 32-33). Feeling confident, then, that this principle must be part of UG, we conclude that it should hold universally in all human languages, and it does. Later we find more components of UG (principle of subjacency, trace theory, specified-subject condition, etc.). "From one point of view, we can properly say that these principles provide explanations for the fact that the data are such-and-such, and thus go well beyond the descriptions of such facts in particular grammars. From another point of view, the same principles serve to account for an important aspect of human learning, that is, for the construction of certain cognitive structures that play an essential role in thought and its expression" (p. 111). Just as UG places restrictions on human languages, human learning in general is surely restricted by innate properties of the mind, for example in the domain of scientific inquiry. "An intellectually