  For Arendt the public sphere comprises two distinct but interrelated dimensions. The first is the space of appearance, a space of political freedom and equality which comes into being whenever citizens act in concert through the medium of speech and persuasion. The second is the common world, a shared and public world of human artifacts, institutions and settings which separates us from nature and which provides a relatively permanent and durable context for our activities. Both dimensions are essential to the practice of citizenship, the former providing the spaces where it can flourish, the latter providing the stable background from which public spaces of action and deliberation can arise. For Arendt the reactivation of citizenship in the modern world depends upon both the recovery of a common, shared world and the creation of numerous spaces of appearance in which individuals can disclose their identities and establish relations of reciprocity and solidarity.