Slavery versus the caste system, it is difficult to ascertain which is worse.  On the one hand, if you were born into the lowest caste system in India (untouchable) you were relegated to the work that was considered unclean or polluting to the higher castes. These included but not limited to morticians, executioner's, tanners, sweepers, and other assorted manual laborers.  The person was not a slave in the sense that they were bought and sold by others, but they were a slave to system that would not let them rise higher in their station in this life, but hopefully the next.  The Romans on the other hand, by the time of Christ, built an empire that counted approximately 30-40% of its population as slaves. These slaves were mostly made up of prisoners from their many wars and conquests of other civilizations. Slaves were bought and sold and could be killed or assaulted by their owners at will, but could also in some cases buy their way out, and eventually live free and even own slaves themselves.  Slaves in the Roman empire worked in every aspect of life including holding important positions in government. They were also scholars, teachers, writers, and doctors.  Each system was an outgrowth of these two different and distinct cultures, and represented a method for exploiting people, that in my opinion,was both morally and ethically corrupt.  Not to mention cruel, debasing, inhuman, and a blight on each civilization.  Unfortunately, some forms of both of these systems endure today in areas around the globe, and are no less as dehumanizing.