 The issue on which empirical research can and should be done is whether some of the unlearned prerequisites that humans enjoy have specifically linguistic content. For a philosophically-oriented discussion of the matter, see chapters 4–6 of Stainton (2006). For extensive debate about “the argument from poverty of the stimulus”, see Pullum and Scholz (2002) together with the six critiques published in the same issue of The Linguistic Review and the responses to those critiques by Scholz and Pullum (2002).