Call a semantics for a given language externalist just in case it assigns to any expression of the language in question an "entity in the world" as its semantic value (perhaps relative to a context or other parameters). When semantics assigns individuals to names and sets of individuals to one place predicates, this is an example of extensional semantics becoming externalist: externalist semantic theories posit a semantic relation between the expressions of the language and entities in the world. For the purposes of discussing externalist semantics in this article, the author sticks with names and one-place predicates, considering Chomsky's opposition to externalist (or reference-based) semantics.