There is a vision of mankind as divided naturally into non-overlapping groups, called nations, each nation enjoying its own single government, legal system, army, and church, each occupying a fixed and clearly delineated and continuous territory. The vision sees all persons living within each such territory as speaking a common language, reading the same newspapers, sharing a common history, racial origin, culture, and traditions, and it sees all of them as feeling loyalty towards, and as identifying themselves with, their nation for the very reason that these things are shared. This reason may be more or less explicitly formulated and more or less in correspondence with the facts. Were the vision to be realized in full - Iceland is the best example - then there would obtain a one-to-one correspondence between nations, states, languages, cultures, races, and territories. Nations, as constituted by the vision, must not be too large: they must embrace no mixtures of, for example, languages or cultures. But neither must they be too small: if necessary they must expand to accommodate all those who share a given language, culture, historical or racial origin.