But those acts are still not inherently evil, nor would they be if everyone on earth thought they were.
If everyone on earth thought something was evil, that wold make it evil, relatively. Unless you are saying it's absolutely not evil.
"Good" and "evil" are simply labels that are put on things we, either as an individual or a society, like and, respectively, disagree with - and thus something can never be proven to be absolutely moral or amoral. I might consider something immoral that the next generation accepts as a standard practise, while they, in turn, could abhor things that I support. You cannot make the claim that there are moral absolutes, even if they are universally applied, as the next generation might have a need to disregard the ancient taboos and adopt a forbidden practice - something that would disprove the absolute "evil" nature of the act. Maybe Walsingham is correct, and this entire discussion is pointless, but I do not agree.
I'm not saying that what we define as good or evil can't change. I was saying that as long as every single person on earth or in one society thought something was evil, then it would be evil in the confines of that earth/society. As long as you set a context, anything can be absolute, and as long as we don't set a context, then everything can be relative. This applies to everything and not just morality. So I can say there is a moral absolute if there is a context for it to be put in.