Do Kind Terms Denote Kinds?

According to the causal theory of meaning, to confer meaning onto a kind term isto fix a kind as its reference. I argue that this is incompatible with the claim thatmeanings are open textured, i.e. that semantics can underdetermine reference. Thetwo views, fixed reference and open textured reference, entail competing claimsabout the course of science. By examining an episode from the history of science,the discovery of isotopes, I conclude in favor of open texture for natural kind terms.I conclude that kind terms cannot denote kinds which refutes the causal theory ofmeaning.