In principle all these three statements are completely wrong (https://en.wikipedia.org/wiki/0#History).
Babylon had a 0 symbol (ð’‘Š, I think) by 300 BC. The Olmecs and/or Maya had the Long Count (and presumably a 0 symbol) by at least 100 BC, although the first known contemporary long count date with a 0 by around 357 AD.
The point is that there's no such thing as a universal right. There are only rights some individual believes should be universal rights. If enough individuals band together, they can get those rights enshrined by whatever authority has the ability to grant and recognize rights for those people, but as long as that authority refuses them, they don't have that right. They just should have that right, according to you or me or whoever.
Again, we all likely agree that there is a moral imperative in play here that slavery should not be tolerated. And had the South won, I'm sure the guy being whipped against a post would be super comforted by us sitting around talking about his universal human rights. He could think about them to take his mind off the lashings.
I'm not arguing that rights have no conceptual existence. I'm arguing that conceptual existence isn't the existence that really matters. It's all lovely for me to say that anyone has the right to draw whatever cartoons they want, but there are 30 million people in Saudi Arabia who would rightly call me an idiot. The actual existence of the right is not some airy concept that I just get to define because it pleases me. It's a very practical thing that affects people's daily lives, and I don't get to declare otherwise just because it suits me.
Revolts only started working during the enlightenment era when the idea of rights started being supported by the nobles as well. Conceptually at least. That's where we got the French Revolution, worker's rights in the 19th century, and stuff like that.
Think about it, until the 1st world war or thereabouts, we as commoners didn't even have the right to free time.
The mathematical anti-realist would disagree.
Likewise, all human beings have always had fundamental rights [...]
Where do they come from? How did we discover them?
More so, you are wrong that the discussion of rights has only happened in the modern era. Elaine Pagels, a historian of early Christianity, has studied why women and slaves were often the strongest supporters of early Christianity -- part of the answer is the Christian church fought for their rights. Pagels offers, as an example, a priest in North Africa who felt that slave owners should be punished if they raped their slaves. At the time, the idea was counter to Roman law, but of course the millions of slaves in the Empire were supportive of such ideas.