The Language Instinct by Steven Pinker

Pinker argues that we have a language instinct, i.e. brain parts that work as hard-coded grammar parsers. In order to do that, he needs to show that there's a bound on possible language grammars. Anything inside the bound would be learnable, anything outside the bound would be unlearnable. Just because we can classify all extant languages, that doesn't imply a boundary. If anything, it implies path-dependency, which sounds like a better story to me, given that each new generation has to learn the current language.

It may be that we have meta-grammar hardware. However, disentangling that from the general processing facilities looks a bit difficult. Regardless, Pinker does relate some good quotes:

a language is a dialect with an army and a navy
-- Max Weinreich, Chapter 2, Chatterboxes
In Boston ... a woman who landed at Logan Airport ... asked the taxi driver, "Can you take me someplace where I can get scrod?"
He replied, "Gee, that's the first time I've heard it in the pluperfect subjunctive."
-- Chapter 5, Words, words, words
Think about having to memorize a new batting average or treaty date or phone number every ninety minutes of your waking life since you took your first steps.
--Chapter 5, Words, words, words
or IP addresses, or passwords, or words in a foreign language...