On the treatment of slaves 

Epictetus – Discourses Book 1
I.13. On the treatment of slaves

If your slave won’t do your bidding,
You must bear with him as you bear with your brother,
We are all children of God.

Just because you are placed in a position above others,
Are you going to behave like a despot?
Remember you are governing fellow descendants of God.

You think you can hold a slave in contempt, because you own him?
Don’t you see that you are valuing the law of mortals,
Above the natural law of the universe?