For a system of values (morality) to exist in a world that fails to demonstate any form of perfection, man must be inborn with a sense of an exterior measurement. For example, think of the metric system in a world of unlabeled distances (since morality is a form of measuring actions). Without a perfect (absolute) meter stick locked up in a museum somewhere, evaluating distances in metric becomes meaningless. Without absolute measurements, the entire concept of judging specific distances quantitatively is an exercise in futility. "What's right for her may not be right for me" is an result of this empty reasoning.