*sigh* I do not argue for slavery, I think its foolish.
I can see (theoretically understand, just barely justify) a person owning slaves and actually being a good, humble, honest person. But, if I were faced with a slave system, either side, I would do what I could to assist its removal.
Sorry, I am libertarian (primarily "US libertarian party", but also libertarian, sorry for my inability to communicate), I edited that out before you posted, and I'm not sure why I edited it out, guess I'm just wierd like that...
Also, about alcohol; it is harder for alcohol to become a problem than for slavery, I just use similar reasoning i regards to why I won't practice/support either. But, I wouldn't support prohibition, it'd just be stupid to that.
And with regards to ancient slavery, some had it nice, but it doesn't take much research to find out what the Assyrians, Egyptians, or Romans would do to their slaves. The Assyrians were especially disgusting...