> We are rightfully condemning chattel slavery. However we can't do that if we are not appealing to a universal moral standard. We have no right to claim that t

> We are rightfully condemning chattel slavery. However we can't do that if we are not appealing to a universal moral standard. We have no right to claim that the Southern states were wrong, if slavery in the way existed back then wasn't universally wrong. I really don't understand why you think there is a need for a universal moral truth in order to have a self-consistent moral code. We didn't believe that every human being has certain rights, which is why our ancestors did not perceive chattel slavery as immoral. We now do, and the actions of our ancestors are appalling to our modern perspective, but we cannot at all believe that this means we are "right" and they are "wrong" by appealing to a universal moral code. We can point out that certain moral codes lead to better outcomes (golden rule and all that), we can reason that society is better off enforcing stricter moral standards and we can build societies that enshrine some of these moral rules as laws, all without a universal morality existing at all. The comparison to physics does not help here. Morality is entirely dependent on a set of subjective beliefs, such as the one I mentioned above about human rights. Physics is not. The world is either flat or it isn't, but two different groups of humans can have diametrically opposed beliefs about, say, veganism and neither of them is necessarily wrong.