  Perry (1977) and Kaplan (1989a) take the relevant mediators of belief to be characters (Perry calls them ‘roles’). An agent can believe a proposition under one character, but fail to believe it under another character. This is John’s state when he first sees the messy shopper at \(t_0\), and he is willing to utter ‘He is making a mess’ but is not willing to utter ‘I am making a mess’. Perry and Kaplan also hold that a rational agent can believe a proposition under one character and also believe the negation of that proposition under a suitably different character. This is what happens when John utters ‘He is making a mess’ and ‘I am not making a mess’ in the slightly modified example: John believes the singular proposition that John is making mess under the character of ‘He is making a mess’ but believes the negation of that proposition under the character of ‘I am not making mess’. He is rational because the second character is not the negation of the first character (roughly speaking).