Quote:It might have been accepted back then as normal in a given society but that doesn't make ownership of another human being moral or justified.
Who says? You? Christians had no trouble with slavery until a couple of hundred years ago. NOWHERE does Jesus condemn slavery as a moral evil,neither does the Old Testament.
So far I have been unable to discover a single universal,moral imperative. OF COURSE I consider slavery a social evil and always have; I'm a child of my time and culture... I have no way of knowing what I would have thought ,as a slave or a slave owner, 2000,or even 500 years ago.I suspect I would have simply seen slavery as part of the natural order,like owning and using livestock..
Slavery was most certainly justified on pragmatic grounds in Roman times,at least; cheap and effective labour. Not Greek,not Roman, not Jewish,not Christian or Muslim thinkers had any problems justifying the morality of slavery.
Morality is not absolute,transcendent or universal. It is pragmatic and fluid,changing to accommodate human needs and desires.