The thousands of world religions have one thing in common: NONE of them condemns slavery. The Bible is no exception; the 10 Commandments do not forbid slavery. Moses tells the Israelites to kill the male children and non-virgin females, but take the young virgins for themselves. Even in the New Testament, in Ephesians 6:5–8, Paul states “Slaves, be obedient to your human masters with fear and trembling, in sincerity of heart, as to Christ.” Slavery was considered to be part of daily life.
What about slavery in Islam? Wikipedia states:
Slavery was a mainstay of life in pre-Islamic Arabia and surrounding lands. The Quran and the hadith (sayings of Muhammad) address slavery extensively, assuming its existence as part of society. Islamic sources indicate that Muhammad acquired slaves.
The Roman Empire acquired slaves from their military campaigns. I could go on and on about slavery around the world. Slavery has always been a global, unquestioned phenomenon.
Even in pre-colonial Africa, slavery was prevalent, although in many different forms. I think it is pretty safe to say that the myth perpetuated in the book Roots – of white men going into African villages and enslaving the population – was not the way the system worked. In fact, Africans enslaved Africans, in tribal wars for example, and then took the slaves off to coastal markets like Ile de Gorée in Senegal, to sell to the waiting white men and their transatlantic ships.

Africans enslaved by Africans
Of course, we know that the American founding fathers like George Washington and Thomas Jefferson owned slaves, and thought nothing of it. That was the social and economic practice of the day.
With all this background of thousands of years and billions of people, how can it be that I KNOW that slavery is wrong? It’s ingrained in me, like a priori knowledge, or gnosis. How can I be right while history and all religions are wrong? Even all around our modern world, there are some 36 million slaves, as shown in this map:

In the end, this is not an essay about slavery, but about the grounds for morality. How can I be so sure of my moral position? It’s not a rational argument. How can I even argue with someone who owns slaves? If I say, “Slavery is wrong,” they could just reply, “Well, I say it’s right,” or, “The Bible says it’s right.” End of discussion.
It seems that it would be even harder for Christians to oppose slavery. After all, the Bible – the irrefutable word of God – supports it. Christians, whose morality is the Bible, should all be supporting slavery.
Is my opposition to slavery simply societal conditioning? Can ALL my firmly-held beliefs be traced back to simple societal or parental conditioning? If I had been born into another society, would my views be different?