 It seems that it cannot be the general type of belief that we are interested in here, at least not if the type in question is “belief that water is wet,” since different people (or even the same person on different occasions) could have beliefs of this type which had different narrow contents. Oscar is ignorant of the molecular structure of water; he identifies water as a clear, odorless, colorless substance that falls from the skies and fills the lakes. As we have already seen, Twin Oscar shares Oscar’s narrow content, but in his environment this narrow content determines that he believes that XYZ is wet, not that water is wet. However, an earthly expert chemist who has done years of laboratory research on water, and is well aware of its molecular structure, will have a different water-concept than Oscar does, and his belief that water is wet will have a different narrow content than Oscar’s does. The chemist’s Twin Earth duplicate does not believe that XYZ is wet, since he is aware of the chemical composition of water and his beliefs explicitly concern H2O. He believes that water is wet (though he also believes, falsely, that the substance that fills the lakes and emerges from the taps is water).