A fourth function of national identity is to promote a wide radius of trust, which acts as a lubricant facilitating both economic exchange and political participation. Trust is based on what has been called social capital ― that is, the ability to cooperate with other people based on informal norms and shared values.

Diversity is, moreover, critical to resilience. Environmental biologists point out that artificially produced crop monocultures are often highly vulnerable to disease because they lack genetic diversity. Indeed, such diversity is the motor of evolution itself, which depends on genetic variation and adaptation. Ecologists today worry about the loss of diversity in species around the world in part because this poses a threat to long-term biological resilience.

To the question 'Who is the Comte deX?' the normal answer would have been, not 'a member of the aristocracy', but'the lord of X', 'the uncle of the Baronne de Y', or 'a client of the Duc de Z'

in the modern world everyone can,should, will 'have' a nationality, as he or she 'has' a gender - vs. the irremediableparticularity of its concrete manifestations,