This chapter looks at world-making from the viewpoint of one of its constitutive ingredients: solidarity. Solidarity is the substance of a successful world-making, if world-making is defined as the creation of a common universe. It makes sense to think that in order for this common universe to exist, there must be something that holds it together. Here, I will argue that solidarity should not be conceptualized as the ‘something that holds the common universe together’ but rather as the ‘there must be something that holds the common universe together’. The distinction here lies in a step I think worth taking, which sees in the ambiguous nature of the concept an (often a posteriori) description of a certain social reality at a certain time, and an (often a priori) political project, the two aspects being inseparable. That they coexist historically in such an intimate way is mirrored by the flexibility of the concept. For the imagery of the massive solidity of a people – painted abstractly – we must substitute the idea of a recurrent specification of social bonds with a political view.

This idea, the guiding thread for the following thoughts, unveils the fact that three of the characteristics that have been ascribed to solidarity – reason, abstraction and equality – are more problematic than they would seem to be at first sight. Hannah Arendt, writing on the end of the eighteenth century, expresses with exemplary clarity what we can now call the received twentieth-century view of the concept.