If moral values can be revised spontaneously while language acquisition cannot, the two domains differ in a way that undermines the analogy.

L1/M1 refer to Chomsky’s poverty of the stimulus argument: despite receiving little explicit linguistic and grammatical instruction, children develop language rapidly and at a young age, and quickly come to display competence applying complex grammatical rules. Similarly, Mikhail and other proponents of the analogy argue that children acquire moral knowledge at a young age based on relatively little explicit instruction. However, critics of the analogy point out several points of difference. Fir