Some externalist strategies and their problems

I claim that there are four major strands of argument for externalism and set out to discuss three of them. The four are: (A) That referential thoughts are object-dependent. This I do not discuss. (B) That the semantics of natural kind terms is externalist. (C) That all semantic content, even of descriptive terms, stems from the causal relations of representations to the things or properties they designate in the external world. (D) That, because meaning is a social product and no individual can capture the whole social practice that defines a concept, what the speaker means always outruns what he can know. I briefly discuss (C) and (D) and conclude that they cannot be correct, because, if they were, the content of every thought would permanently transcend the reflective grasp of all thinkers. Then I discuss (B) and conclude that, though Putnam shows something interesting about natural kind terms-namely that a real verbal definition requires science-this has none of the consequences for philosophy of mind that it is normally supposed to have.