Despite the frequent use of the concept of ideology, we still do not know exactly what ideologies, how they are structured, and how they are related to discourse. In the framework on a multidisciplinary project, this paper explores these issues form a socio-cognitive point of view. Thus, ideologies are first defined a basic systems that underlie the social representations (such at the attitudes) of a group. They are constituted by group relevant values and organized by categories that reflect the basic interests or identity of its group and a relation to other groups and society as whole. The polarizing organization of ideologies is reflected in the structure of the manifestations of ideologies in social practices in general and in discour...