There is no reason to downvote a true statement, but it can perhaps be simplified somewhat in that Jefferson did not consider his slaves fully human, thus they

There is no reason to downvote a true statement, but it can perhaps be simplified somewhat in that Jefferson did not consider his slaves fully human, thus they can never be part of the natural aristocracy. Good enough to rape, sure. Good enough to cook his food and clean his clothes but not good enough to lead.