"Who am I to say rape and slavery are wrong?"

[kılıç_mehmet]

Well, the concept of wrong and right have evolved throughout history.
While slavery was a reality of the old world, beyond the concept of right or wrong for the people of the time, for today's world, it is considered to be wrong, as we have at least a uniform list of basic human rights, which guarantee personal freedom from bondage.
Similarly, rape was never really considered to be lawful to exercise on free women, perhaps, but the context which defines rape was changed.
"Rape" was also taken in context of domestic, spousal abuse, and punished accordingly.