I ask myself that question when people speak on and on about some of their cherished assumptions that may in fact be more a construction of reality than a reflection of reality. I recently came across an example of how concepts can take on a life of their own for reasons we may little suspect.
While studying Caesar's Gallic War with a very talented professor and while researching in order to write a paper in this same course, this question came to me: What is the difference between a Celt (Gaul) and a German? These are two of the groups Caesar battles in the Gallic War.
After listening in class and reading further, it seems that the difference between a Celt and a German may simply be Caesar's political ambitions. Let me explain.
Caesar needed a big conquest so that he could get back to Rome and seek a consulship and more power. The land beyond the Rhine was just too big and too challenging to fit into the pressing time frame of his political ambitions. Hence, the area beyond the Rhine becomes the land of the Germans, of a distinct and excessively barbaric people not worth conquering. In contrast, the Celts or Gauls are a doable conquest within the time frame needed by Caesar's ambitions. Hence, the Rhine becomes the ethnic and cultural demarcation between Celt and German and the limit of Roman power, in spite of the fact that the peoples were, from all indications, closely related. See, for example, the comments of F.E. Adcock in Caesar As Man of Letters (Cambridge, 1956), p. 97, at this Google books link.
The rest is history. The French consider themselves Gauls or Celts; and certainly the people across the Rhine consider themselves quite distinctly German. (The work called The Germania by the Roman historian Tacitus would later do much to lay a foundation for German identity and unfortunate German nationalism in the modern era.)
I also recall a N.Y. Times article on DNA research from Oxford University in which the researcher concludes that the peoples of the British Isles (whether Scots or English or Welsh or Irish) are really one stock that migrated from--get ready for this--the Iberian Peninsula! Yet, the article concluded that there was no expectation that this scientific discovery would inhibit the various nationalisms, prejudices, and jingoism of these different, neighboring groups:
The Celtic cultural myth “is very entrenched and has a lot to do with the Scottish, Welsh and Irish identity; their main identifying feature is that they are not English,” said Dr. Sykes, an Englishman who has traced his Y chromosome and surname to an ancestor who lived in the village of Flockton in Yorkshire in 1286.Source link.
Yes, it seems that individuals and even nations can build their identities on arbitrary constructions that have little to do with any inherent or necessary differences between peoples. The Bible tells us that the just shall live by faith. The Bible and experience also tell us that many of us live by comfortable illusions only loosely based on historical fact. Unfortunately, some of these illusions or delusions have led to violence and war. More often, they simply lead to living in an ego-comforting fantasy world.
And so it is quite refreshing to read St. Paul making light of and relativizing so many of our human divisions, even ones that are indisputably real:
28There is neither Jew nor Greek, there is neither bond [slave] nor free, there is neither male nor female: for ye are all one in Christ Jesus.
Galatians 3:28 (KJV).