News Flash: Any Category or Grouping is Artificial

Any grouping of things can be considered an artificial construct: Whenever we categorize, there will be edge cases.  Take the elements: In the periodic table, We categorize them into metals and non metals, but elements on the border between the two, don't show the clear-cut distinctions we see from elements in the heart of their category.

To carry the analogy further.  The table was set up based upon the characteristics of the elements.  Later, when atomic theory came along, the arrangement of the elements agreed perfectly with the number of protons in each element.  It makes sense that atomic structure and behaviour would agree and it assures us that the arrangement was more like rational than arbitrary.

In a similar fashion, you can look at linguistic dendritic trees, which happen to agree very closely to genetic relatedness dendritic trees.  So the groupings may be artificial, but they are clearly based in reality.

To get to the Goldberg fiasco--she's sort of right and wrong at the same time. The German NAZI's certainly thought of Jews as a race and persecuted them as such.  On the other hand, while there are certainly Jews of all races, in Europe they were close to 100% Caucasian.  Goldberg was wrong to think of the NAZI genocide as white-on-white hatred, since the NAZI's thought of Jews as an alien race.  That doesn't change, just because 80 years later very few people think of Jews as a race.