 Some generative Essentialists see a kind of paradox in Gold’s results—a reductio on one or more of the assumptions he makes about in-principle learnability. To put it very crudely, learning generative grammars from presented grammatical examples seems to have been proved impossible, yet children do learn their first languages, which for generative Essentialists means they internalize generative psychogrammars, and it is claimed to be an empirical fact that they get almost no explicit evidence about what is not in the language (Brown and Hanlon 1970 is invariably cited to support this). Contradiction. Gold himself suggested three escape routes from the apparent paradox: