Nouns for Natural Kinds and the Problem of Arbitrariness
This chapter explains the “Kripke-Putnam orthodoxy” about the reference fixing of ordinary natural kind nouns, and some objections to it, especially “arbitrariness problems”: for example, a Kripke-Putnam baptism for “water” doesn’t discriminate between, say, H2O and P2O (H2O where the isotope of hydrogen involved is protium oxide, as in regular paradigms of water). The chapter presents a picture of reference fixing for natural kind nouns that refines the Kripke-Putnam picture and that appeals to sets of roughly sufficient conditions for reference and reference failure. It is argued that on this picture the referents of ordinary natural kind nouns turn out to be “ordinary kinds,” kinds which are vague along dimensions along which scientific kinds are precise: the reference of “water” is “the ordinary kind water” rather than H2O or other scientifically identified kinds. It is argued that this suffices to dispose of the arbitrariness worry on a broadly Kripkean view.