 While dual theorists agree with Putnam’s claim that some aspects of meaning are not “in the head”, others have opted for plain internalism. For example, Segal (2000) rejected the intuitions that are usually associated with the Twin-Earth cases by arguing that meaning (and content in general) “locally supervenes” on a subject’s intrinsic physical properties. But the most influential critic of externalism has undoubtedly been Chomsky (2000). First, he argued that much of the alleged support for externalism comes in fact from “intuitions” about words’ reference in this or that circumstance. But ‘reference’ (and the verb ‘refer’ as used by philosophers) is a technical term, not an ordinary word, hence we have no more intuitions about reference than we have about tensors or c-command. Second, if we look at how words such as ‘water’ are applied in ordinary circumstances, we find that speakers may call ‘water’ liquids that contain a smaller proportion of H2O than other liquids they do not call ‘water’ (e.g., tea): our use of ‘water’ does not appear to be governed by hypotheses about microstructure. According to Chomsky, it may well be that progress in the scientific study of the language faculty will allow us to understand in what respects one’s picture of the world is framed in terms of things selected and individuated by properties of the lexicon, or involves entities and relationships describable by the resources of the language faculty. Some semantic properties do appear to be integrated with other aspects of language. However, so-called “natural kind words” (which in fact have little to do with kinds in nature, Chomsky claims) may do little more than indicating “positions in belief systems”: studying them may be of some interest for “ethnoscience”, surely not for a science of language. Along similar lines, others have maintained that the genuine semantic properties of linguistic expressions should be regarded as part of syntax, and that they constrain but do not determine truth conditions (e.g., Pietroski 2005, 2010). Hence, the connection between meaning and truth conditions (and reference) may be significantly looser than assumed by many philosophers.