In English, in order to speak about Arthur’s attitudes, we use sentences like “Arthur believes that natural language is messy”. For sentences of this kind we have a standard theory, according to which the ‘that’-clause ‘that natural language is messy’ denotes a proposition. As Prior showed for the first time, the standard theory appears to be at odds with some linguistic data. Geach and Prior both assumed that linguistic data are to be taken as reliable guides to a correct semantic (...) account and I will start by raising some worries concerning their methodology. Because of these data, Prior and Geach suggested some non-standard accounts. I will then show that if we take linguistic data seriously, their non-standard accounts do not fare any better than the standard theory. My general conclusion will thus not only be that Prior’s and Geach’s methodology is disputable, but also that their conclusions do not seem to follow even if we grant the reliability of their methodology. (shrink)