The abilities of detecting contradictions and rearranging the cognitive space in order to cope with them are important to be embedded in the BDI architecture of an agent acting in a complex and dynamic world. However, to be accomplished in a multi-agent environment, ldquobelief revisionrdquo must depart considerably from its original definitions. According to us, the main changes should be the following ones: 1. replacing the ldquopriority to the incoming information principlerdquo with the ldquorecoverability principlerdquo: any previously believed piece of information must belong to the current cognitive state whenever it is possible 2. dealing not just with pieces of information but with couples <source, information> since the reliability of the source affects the credibility of the information and vice-versa. The ldquobelief-functionrdquo formalism is here accepted as a simple and intuitive way to transfer the sources' reliability to the information's credibility.