 Intensional transitive verbs are also involved in another puzzle of substitution-resistance besides the one already discussed. In the literature on propositional attitude reports, it’s the received view that the complement clauses in such reports refer to propositions. So, for example, in ‘Holmes believes that Moriarty has returned’, the clause ‘that Moriarty has returned’ is taken to stand for the proposition that Moriarty has returned. The whole ascription is then understood to have the form Rab, which in terms of the example means that Holmes (a) stands in the relation of belief (R) to the proposition that Moriarty has returned (b). However, as well as being denoted by that-clauses, it seems that propositions are also denoted by proposition descriptions, noun phrases that explicitly use ‘the proposition’, such as, in the previous sentence, ‘the proposition that Moriarty has returned’. So, if the clause and the description co-denote, we have the following truth: 