 The doxastic change that Perry underwent when he realized what was happening, the one that explains his change of behavior, can be aptly described (by him, at least), as coming to believe that I am making a mess. It is not aptly described as coming to believe that the shopper with the torn sugar sack is making a mess. Perry already believed that. Nor (Perry argues) is it aptly described as coming to believe that the F is making a mess, for any non-indexical F. For one thing, for any such F (the unique bearded man in a blue shirt at Safeway, the author of “Frege on Demonstratives”, etc.), we can construct a version of the case in which Perry already believed that the F was making a mess, but still persisted in trying to chase the F around the supermarket to tell him that he was making a mess. For another thing, it could easily be that everyone else in the supermarket believed that the F was making a mess, and none of them displayed the embarrassed cart-rearranging behavior that Perry displayed after he realized what was happening. So none of those beliefs looks like it explains Perry’s change in behavior. (At least, not by marking off a doxastic state that tends to give rise—against a typical background of desires and other beliefs—to that sort of behavior.)