Pesetsky [Pesetsky, D. 1982. Paths and categories. Doctoral dissertation, MIT] compares the primitives of c-selection (syntactic categories such as NP, CP, etc.) with those of θ-theory ("agent", "patient", "goal", etc.) and argues that the latter, but not the former meets what we may call the condition of "epistemiological priority". That is, they can plausibly be applied by the learner to provide a preliminary, prelinguistic analysis of a reasonable sample of data and thus can provide the basis for development from the initial state to the steady state.
- Chomsky (1995), a pag.31