Recent attempts to revive the Platonic thesis that moral knowledge is innate have attempted to piggy-back on the perceived success of the Chomskian arguments for the thesis that linguistic knowledge is innate. The most important of these arguments has been the Poverty of the Stimulus argument. Chomskian poverty-of-the-stimulus arguments primarily deny that empiricist learning would allow children to be as competent with the language as they are. Childhood first language acquisition is for the most part invariant with respect to environmental input. If that’s right, then empiricist accounts of language acquisition are inadequate. This is thought to lead to the positive result that the only way to explain fully children’s linguistic competence is by reference to innate knowledge. According to Fodor, “The bottom line of Poverty of Stimulus Arguments, as Chomsky uses them, is that innate domain specific information is normally recruited in first language acquisition” (Fodor 2001). The ideas or propositional knowledge we acquire about some domain, the domain of language in this case, is explained by an innate mechanism specific to that domain.
How natural it seems to run a parallel argument in favor of a kind of moral nativism.