Neither was it presented as the best example. One idea was taken from Athenian beliefs and op then says "It's through this lens that we should consider a wholistic approach ..."
Of course it's easier to throw out a random fact like 'oh slavery' so your argument is moot, but what are you really adding here?
It's not a random fact, it's the counterpoint to invalidate the OP's argument. It's easy to espouse individualism and not have to worry about anything when you have a whole class of people who you can order to do your bidding (to grow food, build buildings, even defend the city).
To answer questions here and in responses, as to what serfs were and how distinct they were or weren't from slaves:
"Serf" is servus in Latin: literally the word "slave". Serfs began as chattel slaves on late-Roman latifundia, but were tied to the land, not to individual owners, by late Roman laws trying to fight depopulation and keep agriculture running.
In the Dark Age, the Carolingian period, and the Viking Age, slaves'/serfs' rights increased due to pressure from the Church, while free commoners' rights decreased, often also due to pressure from the Church. By the end of the Viking Age and the beginning of the Middle Ages proper, official documents spoke of "slaves free and unfree"; by the High Middle Ages, land as well as people was servile or free, so that a serf could own free land (which required a cash rent) or a freeman could own servile land (which required labor service). "Own" here meant "lease", but you could literally buy or sell the lease, or borrow money against it.
A History of Private Life, especially its second and third volumes, and Marriage and Family in the Middle Ages are excellent sources on this.
Serfdom does starts with a specific owner at the start. What separates serfs from indentured servants was: "By taking on the duties of serfdom, serfs bound not only themselves but all of their future progeny."
And of course people where at times forced into serfdom making the slavery connection even more obvious.
This is not a case of someone casting contemporary normative values on an ancient culture in judgement. The parent made a correct positive claim; ancient cultures, including Athens, typically had vastly more inequality than is present today.
It doesn't matter whether or not inequality had a different flavor of cultural sophistication or acceptance attached to it at the time. It remains that the culture is not a good example of equality.
> It remains that the culture is not a good example of equality.
If you take context into account, inequalities in Athens were actually pretty decent compared to other places.
For one citizens were equals (~10% of the population, males only). Women, again for that time, could enjoy a relative freedom and had a place in society. Slaves were quite notoriously well treated in Athenian households, more like mandatory work than inhumane treatment, and a comparatively high proportion would eventually 'earn' their own freedom in Athens. In the wider picture, don't forget that slavery was that age's "industrial" drive, you could not end slavery and have the means to defend the city.
If you look at Athens within its own space and time, it really was a prime example of philosophical and societal enlightenment. It would, as you know, go on as a political model to influence the Roman Republic institutions (sadly a pale copy in practice) and later on the Empire's culture, down to our modern days quest for democracy passing by Revolutions. Judging "humanity" is relative, it can only be done relevantly to a context —that of the deed, and the idea.
> In the wider picture, don't forget that slavery was that age's "industrial" drive, you could not end slavery and have the means to defend the city.
I have a suspicion that much of our moral advancement as a species is essentially a function of our technological advancement. We're not more humane because we have better and more strongly held ideals, but because we're allowed by technology the space to practice them.
As I said above, don't forget that slavery was that age's "industrial" drive, you could not end slavery and have the means to defend the city. It was a life or death situation, and no society at the time found a way to sustain military might without slavery as an economical asset. I take that as a sign that it was no easy change of paradigm.
Later on, machines allowed one man to put out the work effort of several, and things progressively changed, but it took centuries, for hard reasons that I observe are, historically, more economic than philosophical. You could argue that domination or independence should not have been the end goal in civilizations history and I could agree, but then we're not talking about human beings anymore and it all becomes an abstract thought experiment rather irrelevant to our world.