The causal theory of reference is often taken to provide a solution to the problems, such as incomparability and referential discontinuity, that the meaning-change thesis raised. I show that Kuhn successfully questioned the causal theory and Putnam's idea that reference is determined via the sameness relation of essences that holds between a sample and other members of a kind in all possible worlds. Putnam's single ‘essential' properties may be necessary but not sufficient to determine membership in a kind category. Kuhn (...) argued that extension is fixed by similarity-dissimilarity relations that are liable to change in taxonomic reorganizations of science. *Received October 2009; revised January 2010. †To contact the author, please write to: Institute of Philosophy, University of Leiden, Martin de Vrieshof 4, 2300 RS Leiden, The Netherlands; e-mail: [email protected]. (shrink)

Many recent cognitive studies reveal that human cognition is inherently perceptual, sharing systems with perception at both the conceptual and the neural levels. This paper introduces Barsalou's theory of perceptual symbols and explores its implications for philosophy of science. If perceptual symbols lie in the heart of conceptual processing, the process of attribute selection during concept representation, which is critical for defining similarity and thus for comparing taxonomies, can no longer be determined solely by background beliefs. The analogous nature of (...) perceptual symbols and the spatial nature of intraconceptual relations impose new constraints on attribute selection. These constraints help people with different background beliefs select compatible attributes, which constitute a common "platform" for taxonomy comparison. (shrink)