Can the liberal vision of one world ever work?

One of the most elusive and disputed mysteries of life, if not the fundamental mystery, is how homo sapiens has a sense of identity and what its nature is.

We understand that a medieval European peasant - or nobleman - did not think as the new middle and mercantile classes began to think in the 17th and 18th Centuries and that none of them could have seen things as we 'moderns' see things today.

But the explanation for such differences is open to any interest and agenda. It is Religion - no, it's Science. It is Capitalism at work - no, Marxism. It is Society, Culture, IQ, Race. It is Progress. No, it's not - there's no such thing as Progress.

Or could it simply be we live as and with different types of people?

The conservative view today that technocratic governance is stifling individual freedom, and the claim that a common humanity is the fabrication of a left wing elite for its own purposes, need  to  be interrogated, not taken for granted. As should the nativist idea that a man or woman cannot be German or Afrikaans and also feel Austrian and South African, wider still European and African, and beyond that, a member of the human race.

People have more identities, more ideas of themselves on offer now, than the medieval peasant or educated nobleman could ever dream of. Is it possible, in the way of things, some have moved further than others since the 12th, 18th or 20th Century and haven't stopped yet?