@Paul Gowder

What Caledonian said.

Not true? Please, please post about that. Not about moral progress etc, but how you have come to hold that any moral belief can be an objectively true belief. This is surely what 'we now know that's not true' implies.

Aristotle would probably ask you for evidence that he is flatly wrong. He might also ask you why your judgment is true, and his is not.

While I might not agree that we should enslave anyone, I'd certainly have the courtesy to admit to Aristotle that a moral is only as true as a society and an era holds it to be. Is this what you meant?

For your second comment, I'd say that this is a case of a religious given succumbing to overwhelming pressure from society and society's conscience. The Bible was the problem, or at least a justification for the problem. By this rationale, yes, progress was made. However, to temper TGGP's comment a little, 'moral progress' can surely only be made from one set of beliefs towards another set. There is no objective 'morality meter' that we've been inching our way up (down? along?) since the year dot. How could there be? Moral development might be a better way to describe what this post talks about.