 But fine-grained Fregean senses or conceptual structures are not strictly required to distinguish beliefs in identities. Stalnaker (1981; 1987) argues that the metasemantic 2D framework he developed to explain what is communicated by an assertion of an identity sentence can also explain the content of the belief states attributed using an identity sentence to specify its content. If O’Leary were to notice the pole star and think to himself that’s Mars, for instance, the truth-conditions of his thought can be captured by a judiciously defined diagonal proposition (Stalnaker 1987, 125). In this case, the worlds we include in the context set may involve facts about which object is the target of O’Leary’s visual attention and facts about salient empirical properties he associates with the name ‘Mars’. On the metasemantic approach, then, the proposition we attribute in saying O’Leary believes that that is Mars is the proposition that the visually salient object is the object that has those Martian properties.