Sometimes they were taken for religious reasons, or because they were born into the wrong race. Even longer ago they were stolen from one trible by another because their parents  were sturdy and looked like they might produce good fighters.

Sadly it's in our very nature to take what we want and justify it later. Maybe we'll get better, one day... 

 Thank you for your comment. It Gave me a few more lines of thought on the subject. 🫂