about a property of elm trees, it will be considered true or false, depending upon whether that property applies to those trees which are in fact elms. There is nothing "in the head" that could fix his reference thus; rather, he concluded, his linguistic community, containing some speakers who did know the difference between the two trees, ensured that when he said "elm", he referred to elms. Putnam refers to this feature of language as "the division of linguistic labor". See also Ideational theory of meaning Semantic externalism as a response to skepticism Reference theory of meaning Swampman References Putnam, H. (1975/1985). "The Meaning of 'Meaning'". In Philosophical Papers, Vol. 2: Mind, Language and Reality. Cambridge University Press. Semantics Theories of language Epistemological theories Internalism and externalism Theory of mind