Free The Science of Language by Noam Chomsky

only about language, but it's a universal property of growth. The fact that we have arms and legs is a poverty of stimulus property – nutrition didn't determine them. So any aspect of growth – physical, cognitive, whatever – is going to have poverty of stimulus issues. And, at least in the sciences – it's not God, or something – it's universally assumed that it has to do with genetic endowment. So presumably the case of language has to do with genetic endowment. That's Universal Grammar as it has often been conceived.
    Now actually, that's wrong, because it's not due to genetic endowment; it's due to genetic endowment plus laws of the way the world works. Nobody knows how it works, but it's taken for granted by serious biologists in the mainstream that some kinds of developmental constraints or architectural factors play a crucialrole in growth, and also in evolution – in both forms of development. Some notion of evolution and growth, which in genetic cases aren't so far apart – they're going to play a role. So you really have two factors to consider – or rather, three factors. Experience is going to make some choices.Universal Grammar or genetic endowment will set constraints. And the developmental constraints – which are independent of language and may be independent of biology – they'll play some role in determining the course of growth. The problem is to sort out the consequences of those factors.
    Well, what's Universal Grammar? It's anybody's best theory about what language is at this point. I can make my own guesses. There's the question of lexical items – where they come from. That's a huge issue. Among the properties of lexical items, I suspect, are the parameters. So they're probably lexical, and probably in a small part of the lexicon. Apart from that, there's the construction of expressions. It looks more and more as if you can eliminate everything except just for the constraint ofMerge. Then you go on to sharpen it. It's a fact – a clear fact – that the syntactic objects you construct have some information in them relevant to further computation. Well, optimally, that information would be found in an easily discoverable, single element, which would be, technically, its label. The labels are going to have to come out of the lexicon and be carried forward through the computation; and they should contain, optimally, all the information relevant for further computation. Well, that means for external Merge, it's going to involve selectional properties – so, where does this thing fit the next thing that comesalong? For internal Merge, what it looks like – kind of what you would expect in that domain – is that it's the probe that finds the input to internal Merge and sticks it at the edge because you don't want to tamper with it, just rearrange. Well, that carries you pretty far, and it takes you off to features; what are they, where do they come from, and so on . . .[C]
    JM: Noam, that's all the time for today. Thank you very much . . .
    JM: [Discussion continues] To pick up on an issue from the last session, we had been discussing innateness and I think we had come to an understanding to the effect that with lexical concepts we have no clear idea of what it means for them to be innate, but they are .
    NC: Part of the reason for that – for not knowing what it is for them to be innate – is that we don't have much idea what they are.
    JM: Yes. Going further down the list into areas where we have a bit more confidence that we know what is going on, we had come to understand that with regard tostructural features the best way to understand innateness now is probably largely in terms of Merge, that is, a conception of language that focuses on the idea that most of the structure of language is somehow due to this introduction of Merge some fifty or sixty thousand years ago. Is that plausible?
    NC: Well, that is very plausible. How much of language that accounts for we don't really know