This paper focuses on the concept of the reified and consensual universes in the theory of social representations, and the relationship between them. Having examined the different ways in which Moscovici discusses this concept, and the different ways in which these discussions have been interpreted, I will suggest that many of the criticisms levelled at this facet of social representations theory appear somewhat misplaced. However, it does seem that some aspects of the concept of the consensual and the reified universes (...) are rather under-developed within the theory as a whole. It will be suggested that the recent addition of the notion of the representational project to the theory of social representations goes some way towards addressing some of these emergent issues, most notably with regards to the relationship between knowledges from different spheres. As an example, the area of representations of health and illness will be considered: drawing on work that takes the perspective of the sociology of scientific knowledge, it will be suggested that the theory of social representations needs to make the possibility of a bi-directional relationship between knowledge from the fields of scientific and common sense understanding more explicit. (shrink)