 On its face, empty-concept externalism can be supported by a Twin Earth thought experiment (Boghossian  1997).[14]  Consider “Dry Earth”—a planet exactly like ours, except wherever water occurs on Earth, there are only watery looking holograms (though Dry Earthians mistake these for a real kind). The intuition is that unlike Oscar, Dry Oscar uses ‘water’ to express an empty concept. And if Dry Oscar is not referring to water, then as before, the Frege-Carnap view implies that his concept has a different intension or content. So even for empty concepts, content seems determined partly by facts about the environment (including facts about what is absent from the environment).