Knowledge representation and reasoning so far have focused on the ideal ultimate goal, thus stressing logical consistency and semantic homogeneity. On the way to consistent and homogenous knowledge representation and reasoning, inconsistencies and divergent opinions often have to be dealt with. In this article, a social vision of knoweldge representation is proposed which accomodates conflicting views that possibly even result in logical inconsistencies; reasoning is used to track divergent, possibly incompatible viewpoints. This approach to knowledge repsresentation and reasoning has been developped for a social software, a social semantic wiki.