Democracies as common projects of freedom, equality and solidarity are historically and systematically based on a form of recognition of universal personal indeterminacy. If persons are understood politically as free and participating, then this affects not only their understanding of self and freedom, but also their understanding of social and political belonging. Criteria for identifying the affiliation of persons thus become recognizable, firstly, as socio-political constructions, which, secondly, are not able to determine persons comprehensively or to grasp them completely. In a democratic perspective, as is argued here on the basis of the ancient conception of democratic polypragmosyne, criteria for social and political belonging are to be recognized as hypothetical and personal identity as a lifelong process and a category that is always open to questioning.