Following the influential thought experiments by Hilary Putnam and others, philosophers of language have for the most part adopted semantic externalism concerning natural kind terms. In this article, we present results from three experiments on the reference of natural kind terms. Our results confirm some standard externalist assumptions, but are in conflict with others: Ordinary speakers take both appearance and underlying nature to be central in their categorization judgments. Moreover, our results indicate that speakers’ categorization judgments are gradual, and proportional (...) to the degree of similarity between new samples and familiar, “standard” samples. These findings pose problems for traditional theories, both externalist and internalist. (shrink)

Experimental philosophy of language uses experimental methods developed in the cognitive sciences to investigate topics of interest to philosophers of language. This article describes the methodological background for the development of experimental approaches to topics in philosophy of language, distinguishes negative and positive projects in experimental philosophy of language, and evaluates experimental work on the reference of proper names and natural kind terms. The reliability of expert judgments vs. the judgments of ordinary speakers, the role that ambiguity plays in influencing (...) responses to experiments, and the reliability of metalinguistic judgments are also assessed. (shrink)