 In everyday life, the announcement of a contradiction, when recognized as such, is generally not informative; at best, a listener who realizes she is hearing a contradiction learns that there is some problem with the announcer or the announced information itself. However, the announcement of something that is not intrinsically contradictory but merely contradicts existing beliefs is an everyday occurrence of great importance: upon receipt of trustworthy information that our belief about something is wrong, a rational response is to adjust our beliefs in an appropriate way. Part of this adjustment requires a determination of our attitude toward the general reliability or trustworthiness of the incoming information: perhaps we trust it completely, like a young child trusts her parents. Or maybe our attitude is more nuanced: we are willing to trust the information for now, but we still allow for the possibility that it might be wrong, perhaps leading us to later revise our beliefs if and when we learn that it is incorrect. Or maybe we are much more skeptical: we distrust the information for now, but we do not completely disregard the possibility, however seemingly remote, that it might turn out to be true. 