David Braden-Johnson

As a new field, cognitivism began with the total rejection of the old, traditional views of language acquisition and of learning ─ individual and collective alike. Chomsky was one of the pioneers in this respect, yet he clouds issues by excessive claims for his originality and by not allowing the beginner in the art of the acquisition of language the use of learning by making hypotheses and testing them, though he acknowledges that researchers, himself included, do use this method. The most important novelty of Chomsky's work is his idealization of the field by postulating the existence of the ideal speaker-hearer and his suggestion that the hidden structure of sentences is revealed by studying together all sentences that are logically equivalent to each other. This is progress, but his tests of equivalence are insufficient, as they all are within classical logic. This limitation rests on the greatest shortcoming of Chomsky's view, his idea that every sentence has one subject or subject-part, contrary to the claim of Frege and Russell that assertions involving relations (with two-place predicates) are structurally different from those involving properties (with one-place predicates). (See the Appendix below.).

The two characters in this philosophical dialogue, Russell Steadman and Jules Govier, take up the meaning and significance of David Hume’s famous “is-ought gap”—the proscription on inferring a fully moral claim from any number of purely descriptive statements. Building on the recent work of Hilary Putnam and John F. Post, Jules attempts to show that Hume’s rule is of little consequence when discussing matters related to justice or morality as we encounter them in daily life. He derives his conclusion from the observations that all nontrivial human discourse contains, however tacitly, some degree of embedded normativity, and that an overlapping continuum of different types of normativity permits reasonable inference from apparently pure descriptions to fully moral prescriptions. While Russell agrees that moral concepts inevitably make reference to empirical reality, he insists that, precisely in virtue of the tacit normativity of discourse, Hume’s gap persists, rendering fallacious any attempt to fashion an argumentative bridge between the two types of statements. Although the two do not resolve all of their differences, both of their positions shift significantly in response to the other’s insights.