Why is slavery a good thing?

Answer 1

Slavery has never been a good thing.

Taking into account of what I just said, the only time slavery might be considered a good thing is if in ancient times the choice was being a slave or being killed. In the case of ancient Rome as example, after your nation was defeated by Rome, and you were made a slave ( God forbid ) there might be a chance that one's behavior as a Greek slave tutor, freedom might be offered in due time. This is a stretch however, but in ancient Rome, becoming a freedman was a possibility.