 At this point in the Theaetetus, Socrates proposes a model for how false belief can occur, based on an analogy with how signet rings can be impressed into a wax block to produce a sealing: in a similar way, our thoughts and perceptions make an impression on our memory, leaving behind traces which are signs or representations of the original objects thought about or perceived (191c–d; 194c–d). These traces can then be deployed in combination with fresh perceptions of objects, with which they may or may not accord, to produce beliefs. When one of these traces does not “fit” an incoming perception, like a shoe put on the wrong foot, the combination is incorrect and the resulting belief false (193c–194b). The model satisfies both constraints introduced by the earlier puzzles: it provides cases of falsehood where we are related exclusively to things that are, and where both items are in some way present to thought. But as Socrates develops the suggestion, it is made to rely crucially on our having different kinds of cognitive access to the two items combined in the belief (memory traces, on the one hand, and perceptions, on the other: 195c–d). As such, it does not serve to explain cases where just thoughts are involved, as when someone incorrectly believes that the sum of 5 and 7 is 11 (195e–196a). This is enough to vitiate the account Socrates and Theaetetus have given of false belief. But there should no longer be an issue about whether false beliefs are possible, the challenge posed by the original puzzles, only about whether we have been given a fully comprehensive account. Socrates tries to salvage the theory by proposing another model, where having different thoughts is compared to grabbing at birds in an aviary (197c–200d). Here again the constraints introduced by the earlier puzzles are met, but the account does not seem any more promising, if taken as a general theory of false belief. It is soon given up after being subjected to a number of objections, and Socrates returns to the dialogue’s main concern with knowledge. 