All three of these paths have been subsequently explored. Path (1) appealed to generative Essentialists. Chomsky (1981) suggested an extreme restriction: that universal grammar permitted only finitely many grammars. This claim (for which Chomsky had little basis: see Pullum 1983) would immediately guarantee that not all finite languages are humanly learnable (there are infinitely many finite languages, so for most of them there would be no permissible grammar). Osherson and Weinstein (1984) even