Word. When they say "people back then didn't think this was wrong" they're implicitly denying the humanity of the oppressed and enslaved. Abolitionism is born the moment a person is put I shackles, the first time whip meets another's back.

If you watch a mother cry out for her stolen children, a man plead for a moment of respite from back braking labour , a child beg for more food, and you don't see that slavery is wrong then you're a monster.