Contrary to what Marxism has led people to expect, it is pre-industrial society which is addicted to horizontal differentiation within societies, whereas industrial society strengthens the boundaries between nations rather than those between classes. The same tends to be true, in a different form, lower down on the social scale. Even there, preoccupation with horizontal, often subtle but locally important differentiations can be intense. But even if the local group is internally more or less homogeneous, it is most unlikely to link its own idisyncratic culture to any kind of political principle, to think in terms of a political legitimacy defined in a way which refers to the local culture. For a variety of obvious reasons, such a style of thinking is, in these conditions, most unnatural, and would indeed seem absurd to those concerned, were it explained to them.
Local culture is almost invisible.
The most it can do is identify the village of origin of anyone who opens his mounth at the local market. In brief, cultures proliferate in this world, but its conditions do not generally encourage what might be called cultural imperialisms, the efforts of one culture or another to dominate and expand to fill out a political unit. The factors determining political boundaries are totally distinct from those determining cultural limits. But these are not the normal, pervasive conditions of agrarian society. The speakers of a given tribal language may, for instance, not be treated as members of it, if they happen to be of the wrong occupational caste.