If certain kinds of support are possible, then ethical relativism is a false theory - or at least rather implausible. It would lose most of its intuitive appeal.

Other kinds of support may be compatible with ethical relativism. They may even render it more plausible.

So let's ask again what  kinds of support are possible? I accept the notion that science cannot produce ethical rules or principles, but I want to go back to Dee's comment about the possibility of finding some support in our ethical concepts themselves. We have both done some reading on this approach.