What a silly article. They saw themselves as greek, or macedonian, or athenian, or citizens versus slaves. Everywhere in the world people saw themselves and other as where they were from, their culture, etc. Travel was very difficult and most people didn't read, so chances are you'd never see someone from somwhere else with different color or fashion sense.

The first mentions I know of people based on their race in when talking about "the negroe", but it is still implied as being people from Sub Sahaaran Africa, but by virtue of ignorance about individual tribes/regions, a common name was used. I remember a famous criticism to the constitution created after the French revolution that talked about "the rights of men"; instead of the rights of the French, the Englishman, the Turk; which were seen as completely different groups of people given the time and difficulty of travel.

Plus, I dislike the confusion between slavery and racism. People used to take what they wanted by force, and when allowed, they'd take human beings. I doubt it was because they hated other people, instead it was because they were allowed to subjugate other people; motivated by financial/power motives. Enslavement was a common practise until the ideals of humanism won over the super powers of the time; humanism won over human greed.