No, I mock you because you present as absolute truth positions that you aren't willing to defend when their self-contradictions or real-world ramifications are pointed out to you.
But let's take it step by step:
Did slaves have a natural right of self-determination?
You mean like the fact that the people who wrote and signed the Declaration of Independence kept slaves afterward? Self-Contradictions and real-world ramifications like that?
But let's take it step by step:
Did slaves have a natural right of self-determination?
Sure. They never should have been kidnapped in the first place. I will once more point out that this is the Morality of Islam, not the Morality of Christianity.