On Language Log, I came across Universal Grammar haters. For some, the debate rages on about nurture versus nature and I, like this blogger, also think the debate is inane.
My personal slant draws from the field of artificial intelligence where it's an already-firm conclusion that "grammars" aren't just abstract concepts pertaining to linguistics only. In a broader sense "grammar" is structure; it determines the sequential order of computation and clarifies the constituents of a functioning dynamic. So grammar also has relevance in other geeky subjects like computer programming, mathematics, systems theory and digital circuitry. Even our very DNA must have the innate capacity to understand a grammar because, without it, it would surely be hit-or-miss whether a string of gene sequences were executed in a timely order. Grammar is order. Neither you nor I would exist otherwise, let alone our complex brains.
Grammar is, on the most fundamental level, part of any coherent system and necessary to maintain that coherency. So, forgetting about whatever political vendettas one personally has against Chomsky et alia, most emphatically there must be some sort of basic "universal grammar" from which specialized grammars for particular languages are drawn. However this universal grammar must not be misunderstood to be only linguistic in nature but part of the fundamental processes of thought and computation. I believe that one innate capacity of the human brain, bland as it may sound, would be the ability to distinguish an object from an action performed on it.
A brain born without any inherent grammar must surely be a lump of thoughtless meat, fundamentally incapable of computation itself. Thought requires grammar. It's a foregone conclusion that an idea is nothing more than a structure of links to other ideas in an infinite sea we call knowledge. The neuronal structure of knowledge requires an innate grammar to parse it before one can comprehend it. To deny that there is a universal grammar in this sense is to say that the very act of thinking can be learned out of thin air. It can't, no more than you can teach a block of ice to think.