I would argue that they are man made in so far as we have named them. And what we call "good" is really what we find pleasing, or generally in line with how we think things should be. Since not everyone thinks the same (and our thinking is shaped by our society, to a large part, unless we are unusually independent thinkers) then you have cultures, made up of people, butting heads over alternate versions of what is "right" and what is "wrong" or evil.
As a relativist you can of course say that the intolerant have every bit as much right, theoretically, to think whatever they want- but in practice it is necessary to keep them from harming others, because society just functions better that way. This is, I think, the happy marriage of relativism joined with utilitarianism, of a very inofficious kind. It's a perfectly rational way to function, and very pleasant. |