 But then we should be able to substitute proposition-description for that-clause, which, indeed, works well enough for ‘believes’: from ‘Holmes believes that Moriarty has returned’ it does seem to follow that Holmes believes the proposition that Moriarty has returned, even though a side-effect of the substitution is to change the clausal ‘believes’ into its transitive form. However, ‘believes’ is rather special in this respect. Despite (20), examples (21a) and (21b) below appear to have very different meanings: