Why?
Because the abolition of slavery is one of the greatest achievements of our civilization.
New generations of humans are constantly being born, and until we teach them, they don't know why this is. They don't know why slavery was such a black mark on our history. They don't understand what it does not just to the people involved, but to a society. They don't know why it proliferated so easily (and this is still very relevant today; when our society turns a blind eye to illegal immigrant labor, it's an echo of the same economics that made slavery easy for past generations to accept).
You should be able to sit down with a 9th grader and explain to them, this is what slavery was, this is how common it was for most of history. This is why it was so tempting and these are the benefits people reaped from it. But this is how we realized that the costs outweighed the benefits, and how we created a better world at a great cost to many people.
Crucially, it's important to explain to someone how slavery would be bad for them and their community, even if they themselves were not a slave.
It's important to teach all of this to the new humans we raise. "It was bad, end of story" is not enough. The best way for them to learn is to reason through the arguments on both sides, explore the history, see how we got to where we are, and draw their own conclusions. Because you can't force a belief on someone. They need to get there themselves.
If you ban the discussion they are going to reach their beliefs without guidance. And the isolated, the lonely, the angry will end up with some very dark beliefs. It's happening now as a direct response to censorship culture.
I completely understand that slavery is a difficult and very personal topic for a lot of people. These are hard conversations to have. But for the sake of future generations we need to have them. Beliefs are stronger when they're justified. They are strongest when they are challenged, defended, and the challenges are defeated. We should never stop doing that.
