In my view, any rule-based moral system will inevitably give “wrong”, “evil” or “immoral” answers to moral questions under certain circumstances. They may be unlikely circumstances, but I’ve never met a moral code which didn’t fall down under some sets of conditions, recommending behaviour which I would deem unacceptable.
My view of morality is that it is a cache of pre-generated guidelines for resolving moral questions. We cannot hope to reason out an answer every time we are confronted with a moral problem, so we build rules which attempt to encode an approximation of moral reasoning in easy-to-remember formulae. It’s rather like a scientist trying to write an expert system to answer most simple questions in his field of knowledge, leaving only the tricky stuff for him to deal with personally.
People often swap these rules with friends; this is how most children are taught morality. Parents give rules which they have found useful or valuable to their children, and hopefully the children accept those rules and add them to their moral knowledge base.
Of course, this view of morality makes it a human artifact by definition, so it’s not obvious that it’s a very useful starting place for the Absolute Morality Debate. However, we can consider whether there are base moral rules which all people should or must accept as starting points for their self-assembled moral code.
My view is that I am undecided. There may be base morals which everyone must accept, but I’ve yet to find any.