being born into slavery is a random fact -- life happens and they had no control over it really.

many people are meant to be slaves is also a fact -- it is not like everyone is gifted cerebrally, or even blessed to be in an environment where, by the time they are adults, have been shown a good formula for life; so consequently a section of the society is destined to be just slaves, it just needs the presence of a manipulator.

Aristotle, being an endless questioning guy he was, might have figured this out, although i'm not sure.

I'm going to firmly disagree and insist that no one should ever be a slave, and they are not meant to be slaves, regardless of their intellectual capacity or whether they were shown a good formula for life. Human society is in a failed state anywhere in which someone is forced into slavery.

I think you're committing a naturalistic fallacy, and I don't agree at all that people are ever meant to be slaves.

The most I can agree to is that "some humans are born into slavery due to chance". This is factual. That people are meant to be slaves is not a fact. Perhaps we have a language barrier here.